NikonGear'23
Gear Talk => Camera Talk => Topic started by: Akira on July 07, 2016, 08:43:35
-
http://www.dpreview.com/news/8595291296/now-with-4k-fujifilm-x-t2-offers-24mp-improved-af-and-video-specs
Some product images:
http://www.dpreview.com/news/2952778073/hands-on-review-fujifilm-x-t2-mirrorless-camera
First impressions:
http://www.dpreview.com/reviews/fujifilm-x-t2-first-impressions-review
An early review on The Camera Store TV:
https://www.youtube.com/watch?v=QE0M-D39YZM
-
Looks like yet another winner from Fuji ;)
On a side note; Oh I whish Nikon would announce an 'Roadmap' for lenses,,,,
-
Apparently Fuji and Olympus seem to be the most enthusiastic about improved the responsiveness of the mirrorless cameras.
On a side note; Oh I whish Nikon would announce an 'Roadmap' for lenses,,,,
Which reminds me that Nikon has never released any roadmap of their products? Would that be their policy? Of course, no one would want to publish the roadmap for any "replacement" model. :D
-
In the old days there where 'pre-release' or pre-production versions of optics presented at 'events'
-
In the old days there where 'pre-release' or pre-production versions of optics presented at 'events'
That's how I saw Bjørn in person here in Tokyo: Nikon invited photographers from various parts of the world to Japan to unveil their epoch making D3. But the pre-release or the presentation of the pre-production model is not exactly the disclosure of the roadmap: the new products are already there.
-
Back to the topic, I am very excited and if the upcoming real-world reviews will confirm the expected improvements (for me, especially continuous AF) then I will promptly get one.
Otherwise, I'll still be getting one, but with less hurry so that perhaps I can benefit from price drops.
-
There probably will be plenty of second-hand X-T1 cameras available soon ... Good news for anyone keen on getting into the 'X' line.
-
Whilst I doubt that I will get into the Fuji X-line of cameras and lenses, the release of a new camera of the calibre of the X-T2 is something that is always of great interest to me, as it presents the other manufacturers with new competitive challenges. The responses to these new challenges by the other manufacturers will in due course almost certainly benefit me when I buy my next camera.
Therefore let us hope that the X-T2 will prove to be even more successful than its already highly acclaimed predecessor, the X-T1.
-
The X-T2 has got a magnesium alloy body, so the lens mount is not attached to polycarbonate plastic but real metal.
A first for mirrorless is the dual SD card slots in the X-T2.
Fujifilm has by now developed the most comprehensive lineup of lenses, specially designed for APS-C.
-
Apparently Fuji is relatively more serious about improving the fundamental problems of mirrorless cameras, compared to, say, Sony.
-
An additional improvement for the X-T2 is the new "cursor" or dedicated joystick for moving the AF point around as well as using it for moving the enlarged MF focus area.
The rear LCD of the X-T2 can be flipped out horizontally as well as vertically.
Let's see what the rumoured Sony A9 will look like. Sony seems to be all about "full frame" now. I think the X-T2 will have a much better user interface than the Sony A6000 and A6300. The A6300 did't get the new AF "joystick", and is in many ways just a magnesium alloy version of the A6000, albeit with a more modern sensor.
The A7x series have all got two command wheels + the dial on the back + separate EV comp wheel. This makes the A7x series much easier to use than an A6000/A6300 which has only got one command wheel + the dial at the back of the camera. So, A6x00 = total of two wheels/dials and A7x = total of four wheels/dials. This is a tremendous difference. Now if Sony would add the separate AF "joystick"...
-
Apparently Fuji is relatively more serious about improving the fundamental problems of mirrorless cameras, compared to, say, Sony.
That's an interesting statement, but I don't understand what you mean.
Would you care to expand the concept?
-
The rear LCD of the X-T2 can be flipped out horizontally as well as vertically.
What I'm most interested in personally is the construction of this LCD. :)
The AF of APS-C Alpha can be Achilles' heel. The low-light limit of AF of Alpha6300 is rated at -1EV which is a bit outdated.
-
That's an interesting statement, but I don't understand what you mean.
Would you care to expand the concept?
As mentioned, the low-light performance of AF of APS-C Alpha can be a bit outdated. Panasonic cameras can focus in the darkness of as low as -4EV (even the entry model GF7). Olympus doesn't publish the low-light limit of their AF sensitivity, but, based on my experience with E-M5 MkII, its AF performance is practically on par with that of GX8 that I also owned briefly.
The data read-out of the full-frame sensor is inevitably slower than that of the smaller APS-C or m4/3 sensors, which lead to the longer lag in the display of the viewfinder images.
So, neither full-frame or APS-C Sony cameras are as "well-rounded" as those of Fuji or Olympus or Panasonic, even if the image quality offered by the current full-frame and 24MP APS-C sensors can be fantastic.
-
The boost in readout speed in the newest APS-C sensor from Sony comes from the move from aluminium to copper wiring. Likely the full frame sensors can benefit in a similar way. Fuji uses Sony sensors, so Fuji will be behind if Sony is behind, on sensor tech. Sony to the best of my knowledge, is not behind on sensor tech. Note also that Panasonic has not got phase detect AF.
In practice the AF on Sony works well, and -1 EV AF sensitivity has caused me no practical problems. The real challenge lies in the absense of a separate AF point selector rather than AF sensitivity.
Sony's challenge isn't what's inside the cameras, but rather the external user interface of their APS-C cameras.
The menu system should be totally revamped with a touch screen interface like the Hasselblad X1D. This does apply to all manufacturers, since not a single one of them have a really great menu system.
-
The on-site PDAF sensor will be defunct before the light drops to the EV rated in the catalog. Panasonic's AF system independent of PDAF is more consistent and successful. The AF performance should also be highly dependent on the algorithm beside the chip technology. So long as The Camera Store TV reviews are concerned, the video AF performance of Sony is not as reliable as that of Canon.
-
Of course, the AF is more challenging on the larger format, which should be counted in when comparing the technology and the performance of AF.
-
Fuji specifies that contrast AF in the new Fuji X-T2 goes down to -3 EV and says that contrast AF excels in low light, see here http://www.fujifilm.com/products/digital_cameras/x/fujifilm_x_t2/features/page_02.html
This means that the new copper wired Sony APS-C sensor is capable of -3 EV sensitivity when using contrast detection.
What we don't know in some of the Sony specs is, if PDAF or contrast AF is listed. In case a sensor offers both, both should be listed. Here is a list of Sony A7x specs from wikipedia: https://en.m.wikipedia.org/wiki/Sony_A7
It appears that we go from 0 EV to -4 EV depending on the camera body. The A7s models use contrast AF and both go to -4 EV. The A7R2 goes to -2 EV, and has the newest sensor of the A7x models.
This is pretty much a moving target.
-
Also the specification should be for a) static subject, b) an approaching target using a standardized test protocol. It could be e.g. equivalent to a bride approaching the altar in a dimly lit chuch, which is a commonly encountered and often challenging AF problem.
Smaller sensors lead to a more challenging AF problem since the smaller scale of image means the focus must be achieved correspondingly more precisely than with a larger sensor system to reach a given final sharpness in the image. However, it seems typical that larger sensors take more time to read the data for reasons I'm unfamiliar with.
-
As mentioned, the low-light performance of AF of APS-C Alpha can be a bit outdated. Panasonic cameras can focus in the darkness of as low as -4EV (even the entry model GF7). Olympus doesn't publish the low-light limit of their AF sensitivity, but, based on my experience with E-M5 MkII, its AF performance is practically on par with that of GX8 that I also owned briefly.
The data read-out of the full-frame sensor is inevitably slower than that of the smaller APS-C or m4/3 sensors, which lead to the longer lag in the display of the viewfinder images.
So, neither full-frame or APS-C Sony cameras are as "well-rounded" as those of Fuji or Olympus or Panasonic, even if the image quality offered by the current full-frame and 24MP APS-C sensors can be fantastic.
Thank you for explaining.
If you happen to have the opportunity to handle a new X-T2 I'd be interested in your opinion.
-
I love the X. My X100T is a hell of a camera for her price and size. Yet I have so many Nikon options right next to me on my table that I only think of lenses I do not get for Nikon.
Guess what the first lens is that comes to my mind? ... 1.8/75mm Zuiko ... and 4/300 Zuiko ... gosh, I am lusting for these, although I generally do not like the OM-D user interface, but there are still some PENs.
The 1.2/56 Fuji Lens is very very good (and the XPro2 feeld perfect in my hand), but I already have an 85mm Nikkor with very decent bodies to use it on, so what?
In the end I come back to Nikon and hope for the 850 or 900 and more of this wonderful Nikon glass.
-
Fuji specifies that contrast AF in the new Fuji X-T2 goes down to -3 EV and says that contrast AF excels in low light, see here http://www.fujifilm.com/products/digital_cameras/x/fujifilm_x_t2/features/page_02.html
This means that the new copper wired Sony APS-C sensor is capable of -3 EV sensitivity when using contrast detection.
What we don't know in some of the Sony specs is, if PDAF or contrast AF is listed. In case a sensor offers both, both should be listed. Here is a list of Sony A7x specs from wikipedia: https://en.m.wikipedia.org/wiki/Sony_A7
It appears that we go from 0 EV to -4 EV depending on the camera body. The A7s models use contrast AF and both go to -4 EV. The A7R2 goes to -2 EV, and has the newest sensor of the A7x models.
This is pretty much a moving target.
According to the catalog, the lowest limit of AF sensitivity of the newest A6300 is -1EV, which is not impressive. Apparently the relative pixel size (A7S2>A7R2>A6300) is related to the lowest limit of the AF sensitivity (-4, -2 and -1EV respectively).
-
Also the specification should be for a) static subject, b) an approaching target using a standardized test protocol. It could be e.g. equivalent to a bride approaching the altar in a dimly lit chuch, which is a commonly encountered and often challenging AF problem.
Smaller sensors lead to a more challenging AF problem since the smaller scale of image means the focus must be achieved correspondingly more precisely than with a larger sensor system to reach a given final sharpness in the image. However, it seems typical that larger sensors take more time to read the data for reasons I'm unfamiliar with.
Ilkka, thanks for sharing your insight from the practical point of view. Indeed the catalog data don't specify the character of the target, but, in general and according to my experiences, the catalog data coincide pretty well with the real-world performance.
-
Thank you for explaining.
If you happen to have the opportunity to handle a new X-T2 I'd be interested in your opinion.
I will post my impressions here.
That said, the biggest complaint personally would be their retro design craze. The same goes for Olympus (and also Panasonic recently).
-
According to the catalog, the lowest limit of AF sensitivity of the newest A6300 is -1EV, which is not impressive. Apparently the relative pixel size (A7S2>A7R2>A6300) is related to the lowest limit of the AF sensitivity (-4, -2 and -1EV respectively).
The A7S and A7S2 only feature CDAF, A7R2 and A6300 offer PDAF as well, so this is apples and oranges, if you go by pixel size only.
There are two figures to be quoted for mirrorless cameras that feature PDAF, the low light sensitivity for CDAF (contrast) and then the low light sensitivity for PDAF (phase). There is no reason to assume that these coincide a priori.
Both the Sony A6300 and the Fujifilm X-T2 use the new copper wired sensor from Sony. How do you reconcile Fuji stating -3 EV and Sony stating -1 EV? I reconcile those figures this way; Fujifilm states the CDAF figure and Sony the PDAF figure. Indeed Fuji says -3 EV for CDAF on their official web site, stating that CDAF "excels" in low light. Does Sony in their catalogue say if their figure for the A6300 is for CDAF or PDAF?
-
I didn't say that the low-light limit of PDAF and CDAF sensors coincide. Rather contrary. When Nikon released threir first Nikon 1 series, the designers said in one of the interviews that the PDAF will stop functioning earlier than CDAF when the lighting becomes dimmer (although the sensor was not made by Sony at that time). The engineers refrained from mentioning at which EV the PDAF stop functioning.
Considering that the manufactures tend to impress better performances of their products, it should be safe to assume that the low-light limit of AF performance of mirrorless cameras published on the catalogs is based on the performance of CDAF. Then the pixel sizes should matter.
-
Guys , a very interesting discussion. There are a few people that try and work out how different manufacturers "cheat" on their marketing. Since I shoot with Sony, Olympus and Nikon I just work out what cameras work for different things as I shoot my normal images and not worry too much about the technical details. I keep trying to find a good deal on a Fuji X-trans just to give one a try but little success so far. Fuji's seem to hold their value well. I really wish Sony would simplify their UI (and drop the prices) . Funny, but for what and how I shoot, the Sony a7II is not miles ahead of my D700 IQ-wise :( . I just could not justify the expense of a7RII or a7sII. In hindsight, should have bought fewer Native lenses and gone for the better body ;)
The X-T2 looks a very nice upgrade.
Tom
-
Funny, but for what and how I shoot, the Sony a7II is not miles ahead of my D700 IQ-wise :( . I just could not justify the expense of a7RII or a7sII. In hindsight, should have bought fewer Native lenses and gone for the better body ;)
That is interesting. The D600/610/750-Chip inside the A72 is well above the D700 offering. It counts roughly three times the photons at the same ISO. Now that is should be somewhat degraded by Sony peripherels? Very interesting.
-
I wish more cameras followed Fuji's classic button design with all the dedicated dials clearly marked on top.
One look is enough to see which lens is being used, at which aperture, shutter speed, ISO, etc.
(http://1.static.img-dpreview.com/files/p/articles/2952778073/FujifilmXT2-02.jpeg)
Image hosted on DPR
I like the button programmability of my Sony's but basic functions should just have dedicated buttons or dials like on the Fuji or Df cameras IMHO.
-
"... basic functions should just have dedicated buttons or dials like on the Fuji
of or Df cameras IMHO"
Hear hear.
(a Df user since 2013)
-
That's an interesting statement, but I don't understand what you mean.
Would you care to expand the concept?
The weaknesses of the mirrorless design in its current incarnations are not intrinsic to the design but come from the obsession with keeping the cameras small and light.
One drawback compared to the SLR design is higher power consumption, so that for a given battery size mirrorless cameras get fewer shots per charge than SLRs (the XT2, eg, gets 340 shots per 1250 mAh while the D7200 gets 1110 shots out of 2400mAh). So mirrorless cameras ought to have bigger batteries than SLRs, but to keep them small and light they have been given smaller batteries. Fuji has given the XT2 an optional battery grip with two extra batteries that allows you to get 1000 shots per charge - still less than an SLR and the camera is no longer small and light.
Another weakness of the mirrorless design is the short flange focal distance that mirrorless cameras have in order to remain small. There are two aspects to that. The first is that digital sensors are unhappy when light strikes them obliquely. Purely by chance, the long flange focal distance imposed by the mirror of the SLR design is much better for digital sensors. The second is that the short flange focal distance means that the angle between the periphery of the sensor and the back of the lens is large - especially with larger sensors. The result is severe peripheral light fall off, which is dealt with by automatic correction and in Sony's case but not (apparently) Fuji's by designing barrel distortion into the lenses, which then also has to be automatically corrected. This is not ideal for image quality.
A third issue that is not really a weakness of the mirrorless concept but is a contradiction of the design philosophy is sensor-based image stabilisation.
Of those, the only one that Fuji has addressed is stabilisation.
-
I wish more cameras followed Fuji's classic button design with all the dedicated dials clearly marked on top.
One look is enough to see which lens is being used, at which aperture, shutter speed, ISO, etc.
I like the button programmability of my Sony's but basic functions should just have dedicated buttons or dials like on the Fuji or Df cameras IMHO.
I could not agree more with you, JA!
Here is my new old kiddo, following the same philosophy (ISO, Time, Aperture, Distance):
-
It can be argued that the weakest spot in the Fujifilm X cameras is the X-Trans colour filter layout. Very nice results (wrt colour rendition) can be obtained (eg with PhotoNinja) but not so perfect results ("colour starved") with ACR/LR, which today simply is the industry standard for raw conversion. It means that most Fujifilm X users will use that, they might not even realise that better results can be obtained, and they will never switch to another converter. In fact, they might have been better off with a Bayer sensor.
-
It can be argued that the weakest spot in the Fujifilm X cameras is the X-Trans colour filter layout. Very nice results (wrt colour rendition) can be obtained (eg with PhotoNinja) but not so perfect results ("colour starved") with ACR/LR, which today simply is the industry standard for raw conversion. It means that most Fujifilm X users will use that, they might not even realise that better results can be obtained, and they will never switch to another converter. In fact, they might have been better off with a Bayer sensor.
I agree that ACR/LR is poor wrt. conversion of RAF's. I have tested most raw conversion softwares and found Raw Therapee to be superior in demosaic'ing the X-trans pattern.
-
I agree that ACR/LR is poor wrt. conversion of RAF's. I have tested most raw conversion softwares and found Raw Therapee to be superior in demosaic'ing the X-trans pattern.
Thanks for the tip Sten, I will give Raw Therapee a try too
-
Raw Therapee is a mixed bag of surprises. Some good, some not so good. The speed is glacial and stability of the software is not the aspect the developers have paid most attention to in my experience (Win7/10). However, on the other hand, new versions are rapidly forthcoming thus there is always hope one of them works well enough. If one materialises, I'll set up a Linux box for it.
Apparently Raw Therapee 'understands' X-type sensors as it has its own RAW module for X with lots of parameters to experiment with. I'm using RT in order to extract the most from my S3/S5 Pro RAFs, and hope lingers on still.
-
Another weakness of the mirrorless design is the short flange focal distance that mirrorless cameras have in order to remain small. There are two aspects to that. The first is that digital sensors are unhappy when light strikes them obliquely. Purely by chance, the long flange focal distance imposed by the mirror of the SLR design is much better for digital sensors. The second is that the short flange focal distance means that the angle between the periphery of the sensor and the back of the lens is large - especially with larger sensors. The result is severe peripheral light fall off, which is dealt with by automatic correction and in Sony's case but not (apparently) Fuji's by designing barrel distortion into the lenses, which then also has to be automatically corrected. This is not ideal for image quality.
Based on the Fuji XR 14mm/2.8 and 23mm/1.4 lenses I've got, it is clear to me that the very short flange-to-focus distance that Fuji uses has not impeded them from designing distortion-free wide prime lenses featuring normal/fully acceptable amounts of light falloff at the periphery. So with the APSC-sized target at least, it can be done.
-
One look is enough to see which lens is being used, at which aperture, shutter speed, ISO, etc.
This is the key idea.
-
Based on the Fuji XR 14mm/2.8 and 23mm/1.4 lenses I've got, it is clear to me that the very short flange-to-focus distance that Fuji uses has not impeded them from designing distortion-free wide prime lenses featuring normal/fully acceptable amounts of light falloff at the periphery. So with the APSC-sized target at least, it can be done.
I use Sony and have the Sony/Zeiss 16-35/4 and the Zeiss Batis 25/2, and both function very well.
Indeed, all of the wide angle lenses designed natively for mirrorless (Fuji, Sony, Olympus, Panasonic) are retrofocus, but with short back focal distances. Since they are retrofocus, problems with periphersl vignetting and smearing are avoided. Though the natively designed wide angles have a short back focal distance, they are designed with the rear exit pupil suffficiently far away from the sensor, thus avoiding the problem of light hitting the sensor at a too oblique angle. This means that they are designed differently from Leica M compatible rangefinder wide angles.
By looking through a Zeiss Batis 25/2 Distagon, we can see that diameter of the rear exit pupil is much larger than the diameter of the front entry pupil. This is the tell tale sign that we are dealing with a retrofocus design and not a symmetrical wide angle design. Yet the rear lens element is closer to the sensor than what is possible with a DSLR. "Distagon" by the way is Zeiss' label for retrofocus wide angles. The Zeiss Touit 12/2.8 Distagon is made for both Sony and Fuji APS-C mirrorless, and is also a retrofocus type with a short back focal distance.
Specifically, a long back focal distance (distance from the rear lens element to the sensor) is NOT required to make a lens retrofocus. It's only required to make the lens fit onto a DSLR.
-
There is an aftermarket sensor filter for the 135/24x36mm format Sony's that is specifically designed to enable the Leica M and Contax lenses to better function on Sony cameras so equipped - the peripheral vignetting and smearing issues of such lenses on Sony cameras are significantly reduced when this sensor filter is used.
eras I use Sony and have the Sony/Zeiss 16-35/4 and the Zeiss Batis 25/2, and both function very well.
Indeed, all of the wide angle lenses designed natively for mirrorless (Fuji, Sony, Olympus, Panasonic) are retrofocus, but with short back focal distances. Since they are retrofocus, problems with periphersl vignetting and smearing are avoided. Though the natively designed wide angles have a short back focal distance, they are designed with the rear exit pupil suffficiently far away from the sensor, thus avoiding the problem of light hitting the sensor at a too oblique angle. This means that they are designed differently from Leica M compatible rangefinder wide angles.
By looking through a Zeiss Batis 25/2 Distagon, we can see that diameter of the rear exit pupil is much larger than the diameter of the front entry pupil. This is the tell tale sign that we are dealing with a retrofocus design and not a symmetrical wide angle design. Yet the rear lens element is closer to the sensor than what is possible with a DSLR. "Distagon" by the way is Zeiss' label for retrofocus wide angles. The Zeiss Touit 12/2.8 Distagon is made for both Sony and Fuji APS-C mirrorless, and is also a retrofocus type with a short back focal distance.
Specifically, a long back focal distance (distance from the rear lens element to the sensor) is NOT required to make a lens retrofocus. It's only required to make the lens fit onto a DSLR.
-
There is an aftermarket sensor filter for the 135/24x36mm format Sony's that is specifically designed to enable the Leica M and Contax lenses to better function on Sony cameras so equipped - the peripheral vignetting and smearing issues of such lenses on Sony cameras are significantly reduced when this sensor filter is used.
eras
Yes, that's right. It's offered by Kolari Vision.
-
Based on the Fuji XR 14mm/2.8 and 23mm/1.4 lenses I've got, it is clear to me that the very short flange-to-focus distance that Fuji uses has not impeded them from designing distortion-free wide prime lenses featuring normal/fully acceptable amounts of light falloff at the periphery. So with the APSC-sized target at least, it can be done.
Maybe. A retrofocus lens must have barrel distortion (and a telephoto lens must have pincushion distortion). Correction cannot be complete in an asymmetrical lens, and prime lenses in the 20mm (35mm equivalent) range typically have around 2% barrel distortion (Zeiss 12/2.8 2%, Zeiss 21/2.8 1.7%, Sigma 20/1.4 2.4%, Canon 20/2.8 1.9%, Nikon 20/1.8 1.6%, Nikon 20/2.8 2.3%, Pentax 21/3.2 2%). According to Photozone the Fuji 14/2.8 has 0.4% measured distortion and the 23/1.4 less than 0.3%, in both cases the same in RAW and JPEG. Those are incredibly (literally) low values. There has to be a suspicion that they are correcting the distortion in RAW.
The 14/2.8 has 2.4 stops of light fall-off at f/2.8 and 1.8 stops at f/4. There are no direct comparisons but the Nikon 20/1.8, eg, has, on FX, 1.2 stops of light fall-off at f/2.8 and the Nikon 12-24/4 has 1 stop of light fall-off at 12mm and f/4. The Fuji 23/1.4 has just over 2 stops of light fall-off at f/1.4. The Nikon 24/1.4 has 0.9 stops of light fall-off on DX at f/1.4.
Of course, everyone decides for themselves what is acceptable, but it is clear that the mirrorless user pays a penalty.
-
According to Photozone the Fuji 14/2.8 has 0.4% measured distortion and the 23/1.4 less than 0.3%, in both cases the same in RAW and JPEG. Those are incredibly (literally) low values. There has to be a suspicion that they are correcting the distortion in RAW.
The XF 35/2WR has significant barrel distortion; it is NOT corrected in RAW.
-
Maybe. A retrofocus lens must have barrel distortion (and a telephoto lens must have pincushion distortion). Correction cannot be complete in an asymmetrical lens, and prime lenses in the 20mm (35mm equivalent) range typically have around 2% barrel distortion (Zeiss 12/2.8 2%, Zeiss 21/2.8 1.7%, Sigma 20/1.4 2.4%, Canon 20/2.8 1.9%, Nikon 20/1.8 1.6%, Nikon 20/2.8 2.3%, Pentax 21/3.2 2%). According to Photozone the Fuji 14/2.8 has 0.4% measured distortion and the 23/1.4 less than 0.3%, in both cases the same in RAW and JPEG. Those are incredibly (literally) low values. There has to be a suspicion that they are correcting the distortion in RAW.
The 14/2.8 has 2.4 stops of light fall-off at f/2.8 and 1.8 stops at f/4. There are no direct comparisons but the Nikon 20/1.8, eg, has, on FX, 1.2 stops of light fall-off at f/2.8 and the Nikon 12-24/4 has 1 stop of light fall-off at 12mm and f/4. The Fuji 23/1.4 has just over 2 stops of light fall-off at f/1.4. The Nikon 24/1.4 has 0.9 stops of light fall-off on DX at f/1.4.
Of course, everyone decides for themselves what is acceptable, but it is clear that the mirrorless user pays a penalty.
Let's compare these figures to two Nikon mount 20/21mm lenses. The Nikon AF Nikkor 20/2.8 has a vignetting of 2.26 EV at f/2.8 and the Zeiss ZF.2 21/2.8 has a vignetting of 1.99 EV at f/2.8 which is less than 0.5 EV difference from the Fuji 14/2.8 at f/2.8. It is well known that all lenses will vignette less as you stop them down, so comparing a lens that starts at f/1.8 to one that starts at f/2.8 may be a skewed comparison.
Let's consider distortion, and compare the Zeiss Loxia 21/2.8 for mirrorless Sony and the Zeiss Milvus/ZF.2/ZE 21/2.8 for DSLRs. Both are retrofocus Distagons.
Zeiss Loxia 21/2.8: http://www.zeiss.de/content/dam/Photography/new/pdf/en/downloadcenter/datasheets_loxia/loxia_2821.pdf
Zeiss Milvus/ZF.2/ZE 21/2.8: http://www.zeiss.de/content/dam/Photography/new/pdf/en/downloadcenter/datasheets_milvus/milvus2821.pdf
From the graphs for distortion, we see both lenses have very similar, about 2% barrel distortion without any digital correction applied.
The graph for vignetting indicates approx. -2 EV for the Milvus/ZE/ZF.2 (DSLR) lens. The graph for the Loxia (mirrorless) indicates less, but I think that one is digitally corrected.
Both the mirrorless and the DSLR Zeiss 21/2.8 show very similar quality MTF graphs, though the mirrorless lens has a more gentle curve drop off toward the corners, where the DSLR lens drops more abruptly near the edge.
The takeaway for Zeiss is that distortion is comparable for the DSLR and mirrorless lenses.For the Fuji 14/2.8 and corresponding full frame DSLR Nikon 20/2.8 and DSLR Zeiss 21/2.8 the vignetting is actually comparable rangin from 1.99 EV to 2.4 EV. My guess for the Zeiss Loxia 21/2.8 is an uncorrected vignetting between 2-2.5 EV.
In summary it appears that little, if anything is given up with mirrorless wide angles. In the case of Zeiss, the mirrorless Loxia 21/2.8 weighs 398 grams, about half of it's DSLR sibling, so some weight is lost. ;)
-
The XF 35/2WR has significant barrel distortion; it is NOT corrected in RAW.
Digging further, it appears Fuji includes lens correction parameters in all its RAW files. Lightroom and ACR use that information to automatically correct the RAW files, and as I understand it you can't turn that off (which would account for Photozone's results). Some other converters do allow you to turn the correction off.
According to Imaging Resource the Fuji 35/2 does not have significant distortion in the uncorrected files (http://www.imaging-resource.com/lenses/fujinon/xf-35mm-f2-r-wr/review/).
The 35/2 and the 35/1.4 are both quasi-symmetrical designs (http://www.fujifilm.com/products/digital_cameras/x/fujinon_lens_xf35mmf2_r_wr/specifications/ and http://www.fujifilm.com/products/digital_cameras/x/fujinon_lens_xf35mmf14_r/specifications/) - as you would expect a "normal" lens to be - so it would be surprising if they did have much distortion.
-
Photo Ninja, which I use, does not read Fuji lens correction parameters.
I use PT Lens for lens correction.
PT Lens has determined that the Fuji 14mm does not require any correction. http://epaperpress.com/ptlens/profileInt.html#FujinonLenses So it seems likely that this lens at least does not have lens correction parameters in the raw file.
-
That Fuji 14/2.8 must be a very fine lens. Very few lenses get the note "no correction needed". The Olympus 75/1.8 and the Sony Zeiss 135/1.8 are in the same distinguished club.
Most double Gauss normal lenses will have at most 1-2% distortion, many less than that. Double Gauss lenses, or Planar in Zeiss speak for DSLRs have a front group that is more negative than the rear group in order to increase the back focal distance to allow for the mirror box.
-
Photozone use jpeg files from D3x with a flat profile to get vignetting data for Nikon mount lenses. They go on to say that Canon files show 40% more vignetting due to a more agressive profile in their Canon test camera. One must wonder... ???
-
Let's compare these figures to two Nikon mount 20/21mm lenses. The Nikon AF Nikkor 20/2.8 has a vignetting of 2.26 EV at f/2.8 and the Zeiss ZF.2 21/2.8 has a vignetting of 1.99 EV at f/2.8 which is less than 0.5 EV difference from the Fuji 14/2.8 at f/2.8. It is well known that all lenses will vignette less as you stop them down, so comparing a lens that starts at f/1.8 to one that starts at f/2.8 may be a skewed comparison.
Let's consider distortion, and compare the Zeiss Loxia 21/2.8 for mirrorless Sony and the Zeiss Milvus/ZF.2/ZE 21/2.8 for DSLRs. Both are retrofocus Distagons.
Zeiss Loxia 21/2.8: http://www.zeiss.de/content/dam/Photography/new/pdf/en/downloadcenter/datasheets_loxia/loxia_2821.pdf
Zeiss Milvus/ZF.2/ZE 21/2.8: http://www.zeiss.de/content/dam/Photography/new/pdf/en/downloadcenter/datasheets_milvus/milvus2821.pdf
From the graphs for distortion, we see both lenses have very similar, about 2% barrel distortion without any digital correction applied.
The graph for vignetting indicates approx. -2 EV for the Milvus/ZE/ZF.2 (DSLR) lens. The graph for the Loxia (mirrorless) indicates less, but I think that one is digitally corrected.
Both the mirrorless and the DSLR Zeiss 21/2.8 show very similar quality MTF graphs, though the mirrorless lens has a more gentle curve drop off toward the corners, where the DSLR lens drops more abruptly near the edge.
The takeaway for Zeiss is that distortion is comparable for the DSLR and mirrorless lenses.For the Fuji 14/2.8 and corresponding full frame DSLR Nikon 20/2.8 and DSLR Zeiss 21/2.8 the vignetting is actually comparable rangin from 1.99 EV to 2.4 EV. My guess for the Zeiss Loxia 21/2.8 is an uncorrected vignetting between 2-2.5 EV.
In summary it appears that little, if anything is given up with mirrorless wide angles. In the case of Zeiss, the mirrorless Loxia 21/2.8 weighs 398 grams, about half of it's DSLR sibling, so some weight is lost. ;)
It is worth noting for other people that Zeiss' data sheets give data for radial distortion, while Imatest and other test systems use TV distortion, which is a related (and generally better) measure: Zeiss' 2% is not the same as the 2% you see in lens reviews.
I didn't say that high levels of distortion were a consequence of the mirrorless design: peripheral light fall-off is a consequence of the mirrorless design and allowing barrel distortion mitigates peripheral light fall-off, and it appears that mirrorless manufacturers have taken advantage of that in some lenses. So the fact that some mirrorless lenses do not have more distortion than their SLR equivalents is irrelevant.
Zeiss lenses consistently (notoriously, one might say) have a lot of light fall-off, so the fact that a mirrorless Zeiss and an SLR Zeiss both have a lot of light fall-off has more to do with Zeiss than with the mirrorless design. And, as you point out, we don't actually know what the uncorrected light fall-off is for the Loxia because they don't tell us. Why do you suppose that is? The Nikon 20/1.8 has 1.2 stops of light fall-off at f/2.8 - and it weighs 355g. It is not stopping down that clears light fall-off, it is the relative aperture: the fact that the Nikon goes to f/1.8 is irrelevant.
-
According to Photozone the Fuji 14/2.8 has 0.4% measured distortion and the 23/1.4 less than 0.3%, in both cases the same in RAW and JPEG. Those are incredibly (literally) low values. There has to be a suspicion that they are correcting the distortion in RAW.
Les, Your suspicion is justified based on all known principles. I questioned the results I was seeing also. However, I can report that with both my 14mm/2.8 and 23mm/1.4 Fuji lenses, I have mounted them to the camera(Fuji XE1) with plastic tape inserted between the lens and camera electronic contacts, so the camera had no way of 'knowing' what lens was attached. In the Fuji menu system it's called "Shoot Without Lens". It's the same setting as when one shoots with a 'dumb' 3rd party adapter that has no communication with the body.
Results: Same apparent lack of distortion.
Results from the Fuji 14mm are reminiscent of...although not the same as... the clean, distortion-free images as one got with the a Leica M camera and the 21mm/3.4 Super-Angulon.
-
Even with a "dumb" lens the camera might do some trickery on its own ... For example, a Nikon has the same ability to reduce CA for in-camera generated jpgs irrespective of the lens being known to it or not.
-
It is worth noting for other people that Zeiss' data sheets give data for radial distortion, while Imatest and other test systems use TV distortion, which is a related (and generally better) measure: Zeiss' 2% is not the same as the 2% you see in lens reviews.
I didn't say that high levels of distortion were a consequence of the mirrorless design: peripheral light fall-off is a consequence of the mirrorless design and allowing barrel distortion mitigates peripheral light fall-off, and it appears that mirrorless manufacturers have taken advantage of that in some lenses. So the fact that some mirrorless lenses do not have more distortion than their SLR equivalents is irrelevant.
Zeiss lenses consistently (notoriously, one might say) have a lot of light fall-off, so the fact that a mirrorless Zeiss and an SLR Zeiss both have a lot of light fall-off has more to do with Zeiss than with the mirrorless design. And, as you point out, we don't actually know what the uncorrected light fall-off is for the Loxia because they don't tell us. Why do you suppose that is? The Nikon 20/1.8 has 1.2 stops of light fall-off at f/2.8 - and it weighs 355g. It is not stopping down that clears light fall-off, it is the relative aperture: the fact that the Nikon goes to f/1.8 is irrelevant.
I know perfectly well that there are different meassures of distorion, which is why I stuck to Zeiss's data sheets for comparing Zeiss lenses.
Btw. relying on photozone.de, it possible to obtain two values for vignetting for the same lens at the same aperture by testing it on different cameras. Check out Zeiss 21/2.8 on Canon and Nikon respectively. Which do you believe?
This test of the Zeiss Loxia 21/2.8: http://phillipreeve.net/blog/rolling-review-zeiss-loxia-distagon-2-821mm-t/ , shows real vignetting at f/2.8 to be at 2.5 EV, and I guessed at an interval of 2-2.5 EV. :) Zeiss knows perfectly well that data for uncorrected vignetting can be extracted by just taping over the electrical contacts. Thus speculation about why they didn't publish it are futile. The aperture of Loxia lenses is mechanical, like Leica M lenses.
The Loxia 21/2.8 has a 52mm filter thread compared to 77mm for the Nikon 20/1.8. The Nikon lens is a modern AF design, and the Zeiss lenses are both old school MF lenses, which is why I compared the Zeiss lenses at the outset. Fewer variabels.
-
Even with a "dumb" lens the camera might do some trickery on its own ... For example, a Nikon has the same ability to reduce CA for in-camera generated jpgs irrespective of the lens being known to it or not.
Correction of CA is my happiest memory from Nikon Capture (NX?). It was the first software I had, that could do it.
I think in camera distortion correction is impossible without knowing the lens, but I wonder more about vignetting.
-
The barrel distortion of the XF 35/2 WR can easily be observed in PhotoNinja, which as already mentioned, does not autocorrect distortion. I would never call such an amount of distortion insignificant. Both the 23/1.4 and the 14/2.8 do not show any significant distortion in PhotoNinja at all.
In other words, the low distortion figures for both the 14 and the 23 are most probably the true optical distortion figures.
-
I figured that the distortion data published on the popular online reviews are generally based on the test charts hanging just a few meters from the camera/lens combo. So, the lenses tend to show more distortion than focused at distances. The condition is more disadvantageous for faster lenses which tend to show the strong barrel distortion when focused closely.
As for the retro, design, I don't necessarily dislike the dials. But I don't like the hardware design in which the lesser used dial keep taking up the space (like the shutter speed dial in A or P modes). Also, I don't like the fact that the increment step cannot be changed. Who would still need to set the ISO "manually" by 1/3 steps? (I want Nikon to provide a whole step option in the menu on all models.) Also, I always feel the turning of the dials while pushing the lock button awkward. The command dials do require an extra hand or finger to push the desired function button, but its handling is much nicer than the dials of retro-dsign.
Also, I don't like the film camera design with the extra space on the left-hand side of the body. That space was only necessary to accommodate the film patrone and makes no sense on a digital camera. That extra space makes the holding of the camera feel awkward when switched the orientation of the camera between landscape and portrait. I remember that even Bjørn, the Df advocate, complained about it.
-
Nah. You got the wrong end of the stick, Akira. I positively prefer the "extra" space on the left, as it makes hand holding so much easier. The occasional trend of launching cameras chopped-off to the left (with the rationale as you explain), makes me cringe as handling becomes awkward and ignores the fact that cameras tend to be used by humans with two hands.
-
Nah. You got the wrong end of the stick, Akira. I positively prefer the "extra" space on the left, as it makes hand holding so much easier. The occasional trend of launching cameras chopped-off to the left (with the rationale as you explain), makes me cringe as handling becomes awkward and ignores the fact that cameras tend to be used by humans with two hands.
Bjørn, I remember you claimed the added left-hand side by attaching RRS L-bracket in your "Living and Working with Df" thread. That wouldn't happen on a cameras of the "correct" DSLR design.
-
No, that was *not* my point. You misread me and cannot derive the conclusion you put forth. The RRS factory L-bracket was too thick to allow my fingers access to the aperture ring whilst holding the camera correctly. This is simply an interface adjustment not a change of principle. Slimming the grip by 3-4 mm put the situation right. For other bodies, such as the D600, this problem does not prevail although its RRS bracket is at least as thick, if not thicker, than the stock RRS for the Df. Each camera has to be evaluated on its own for handling ease. It is a 3-D shape.
-
Okay, I stand corrected in terms of the interpretation of your problem with Df and RRS bracket.
But my complaint about the extra space stays true (at least) to me.
-
We agree to disagree. I want both hands to participate actively in the operation of the camera, the lens, and their controls. I want to see easily how the camera is set up for a given purpose.
-
The best UI can be different from person to person. The basic camera set up (shutter speed, aperture, ISO, the remaining frames as well as the exposure compensation) can easily be seen on the LCD in the modern DSLR design, too, albeit not in the same way as in the film camera design.
By the way, do you need to set the ISO value manually by 1/3 steps? Also, you have to set the shutter speed using the command dial anyway to go below 1 sec. or to set it by 1/3 steps.
-
I think we should be happy that different manufacturers follow different paths w.r.t. user interfaces, since then perhaps more people can get a camera he or she really likes and can use creatively, with or without "space on the left side". ;)
-
The best UI can be different from person to person. The basic camera set up (shutter speed, aperture, ISO, the remaining frames as well as the exposure compensation) can easily be seen on the LCD in the modern DSLR design, too, albeit not in the same way as in the film camera design.
By the way, do you need to set the ISO value manually by 1/3 steps? Also, you have to set the shutter speed using the command dial anyway to go below 1 sec. or to set it by 1/3 steps.
Curiously, my D800/E, recent, fairly high-end cameras, cannot show me both the frames remaining AND the set ISO in the top annunciator panel. Hmmm...
I know you asked Bjørn this, but I recently realized that not once in my entire history of possessing digital cameras, now almost ten years, have I ever set the ISO in between the standard full doubling/halving values, ie: 100/200/400, etc.
-
It is worth noting for other people that Zeiss' data sheets give data for radial distortion, while Imatest and other test systems use TV distortion, which is a related (and generally better) measure: Zeiss' 2% is not the same as the 2% you see in lens reviews.
The Zeiss habit of graphing the distortion along the image from center to edge makes sense to me. One can clearly see that many wide (Distagon type) lenses have more distortion at 2/3 out than they have at the edge. My lack of engineering or high geometry education prevents me from understanding how giving an overall percent figure without graphing it by location is more useful.
-
Curiously, my D800/E, recent, fairly high-end cameras, cannot show me both the frames remaining AND the set ISO in the top annunciator panel. Hmmm...
I know you asked Bjørn this, but I recently realized that not once in my entire history of possessing digital cameras, now almost ten years, have I ever set the ISO in between the standard full doubling/halving values, ie: 100/200/400, etc.
Keith, your answer would be as highly appreciated as any experienced photographers.
If I remember correctly, the info structure on the LCD screen on the top cover of Nikon DSLRs was changed in the D7200/750 generation. The display of P, A, S, M settings is gone and instead we can see "both" the ISO and the number of the remaining frames. The full setting info can be seen only on the rear LCD screen by pushing the "info" button.
-
For what it's worth, I very often use the 1/3 EV stops for ISO.
-
For what it's worth, I very often use the 1/3 EV stops for ISO.
On Df? Could you elaborate the situations?
-
Nothing to elaborate, Akira. I just prefer this approach.
-
The barrel distortion of the XF 35/2 WR can easily be observed in PhotoNinja, which as already mentioned, does not autocorrect distortion. I would never call such an amount of distortion insignificant. Both the 23/1.4 and the 14/2.8 do not show any significant distortion in PhotoNinja at all.
In other words, the low distortion figures for both the 14 and the 23 are most probably the true optical distortion figures.
The relationship between lens symmetry, distortion and peripheral light fall-off has been known since the 19th century. So if Fuji have done what you suggest they have discovered a new principle of optics, which they have never patented but which no one else can work out how to copy although anyone can buy the lenses and take them apart and see how it is done. Anything is possible, but that has to be low on the likelihood scale.
-
A little off topic, but possible relevant: what if Fuji has utilised the Slussarev method and introduced coma into the pupils? That would reduce vignetting and based on experience from the (earlier) wide Nikkors using this approach, one can have reduced vignetting and very little barrel distortion. In this case the price to be paid is of course the necessity of adding more elements to do a downstream correction for the introduced aberration.
Owners of these Fuji lenses could observe the themselves by looking into the lens (front or rear) well stopped down, to see whether the pupil shape alters off axis. My 15 mm Nikkors (f/3.5, f/5.6) both show this effect very clearly. The newer Nikkor 14 mm f/2.8 does not.
-
Google turned up this (and more) on Slussarev: http://photo.net/large-format-photography-forum/00I1bL
Slussarev's method has been used by Zeiss, Nikon, Rodenstock et al., read the third or fourth post in that thread.
A side note here may be the Russar 20mm f/5.6 wide angle design, by Russinovich. That lens has actually been re-issued by Lomography and Zenit Krasnogorsk.
-
Google turned up this (and more) on Slussarev: http://photo.net/large-format-photography-forum/00I1bL
Slussarev's method has been used by Zeiss, Nikon, Rodenstock et al., read the third or fourth post in that thread.
A side note here may be the Russar 20mm f/5.6 wide angle design, by Russinovich. That lens has actually been re-issued by Lomography and Zenit Krasnogorsk.
According to both Rudolf Kingslake and Hubert Nasse (http://lenspire.zeiss.com/en/wp-content/uploads/sites/2/2015/09/en_CLB41_Nasse_LensNames_Distagon.pdf) the design was invented by another Russian, Roosinov (or Roossinov), and later became the Zeiss Biogon and the Schneider Super-Angulon. It is symmetrical, and has a large negative element at both ends, so both the entry and exit pupils are enlarged at oblique angles, and because of the symmetry there is no distortion (the design was intended for aerial reconnaissance cameras). A lens with a large negative front element but not a large negative rear element will show the effect for the entry pupil but not the exit pupil (Kingslake illustrates this with Nikon's 8mm fisheye), and will have a lot of barrel distortion because of the extreme asymmetry - which also contributes to uniformity of illumination.
According to Nasse peripheral light fall-off in Distagon-type designs is due mainly to mechanical vignetting by the mount, which is why it clears as the lens is stopped down. In symmetrical lenses like the Biogon smaller apertures have little effect.
-
A fisheye lens is all about barrel distortion of course. It is also very efficient in terms of the fraction of incoming light actually ending up at the film plane. Thus evenness of illumination is no surprise.
I looked closely on my 15 mm Nikkors and their clearly show the most pronounced enlargement of the entrance pupil. Whatever changes taking place in their exit pupils are much more difficult to observe. They are highly retrofocus optics with huge negative front elements and also show very low barrel distortion (at distance). Very nice lenses for architecture they are.
Up close, their CRC design introduces substantial barrel distortion, just like with the 35/1.4 to name another lens sharing this behaviour.
-
Les, we are talking about the same man, I got the "-ich" at the end of name wrong. Properly transscirbed from Cyrrilic it is Rusinov. More about the original Russar, http://microsites.lomography.com/russar-lens/history/
-
Nothing to elaborate, Akira. I just prefer this approach.
Okay, this would be my last question for this particular topic. Do you like to change ISO value for the exposure compensation or for the intentional over/underexposure rather than tweaking the dedicated exposure compensation dial?
-
I select an appropriate ISO value before I commence a sequence of shots. Spinal reflex from the old days perhaps, but it works.
-
I select an appropriate ISO value before I commence a sequence of shots. Spinal reflex from the old days perhaps, but it works.
Thanks, Bjørn.
-
Yesterday I was able to handle an X-T2 at Camera World, a shop off Oxford Street which I have used several times in the past.
I did not have long, but my immediate impressions were very favourable. It feels like an improved X-T1, with many things familiar but better. The joystick to move the focus point is indeed a joy, and pressing it in to the camera body centres the point. The EC dial is a little stiffer, which makes it harder to nudge accidentally. The ISO and shutter speed dials have a lock/unlock button, so you can lock a setting or have the dial moveable, as you wish. These dials are a little taller than on the X-T1, and easier to adjust without moving the drive and metering mode dials below. Focus seems much faster, and the camera more responsive, but I was not able to carry out a proper test.
The booster grip makes the camera noticeably heavier, but that does include two extra batteries. The grip fits well and is comfortable to hold.
The D pad buttons are slightly raised and easy to operate.
I pre-ordered camera and grip from Camera World, as they offered a very good deal on my old D300 and grip.
All in all, from my brief experience, I would say that Fuji has listened to its customers.
-
TCSTV post a review of the field test using pre-production units:
https://www.youtube.com/watch?v=vUPxVYAnz_E