Author Topic: Question on Leaf-Shutters  (Read 10405 times)

Erik Lund

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Re: Question on Leaf-Shutters
« Reply #15 on: January 16, 2017, 14:29:51 »
Surely, Phase One must be working on a mirrorless system, if they wish to stay in business.

A 100mp DSLR medium format, will require mandatory use of mirror-up, if the capabilities of the 100mp resolution sensor is to be exploited. This means using the camera in LV mode for focus stacking.

My guess is that Fujifilm GFX and the Hasselblad X1D will have the lions share of the medium format market in 2017, unless Leica and Phase One go mirrorless medium format in 2017 too.

I think that medium format DSLR only makes sense for professionals already invested in such systems. Those new to medium format should go mirrorless, considering the future.

I'm afraid the Phase One is a lot more sophisticated than you might think,,,

It has a build-in seismograph that monitor vibrations, it can be set to fire the shutter when there are no vibrations,,, This thing is light-years ahead of the competition,,,
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bjornthun

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Re: Question on Leaf-Shutters
« Reply #16 on: January 16, 2017, 15:30:23 »
I'm afraid the Phase One is a lot more sophisticated than you might think,,,

It has a build-in seismograph that monitor vibrations, it can be set to fire the shutter when there are no vibrations,,, This thing is light-years ahead of the competition,,,
I'm not so sure that they are ahead of the competition, and if they don't have a mirrorless like the Fuji GFX or the Hasselblad X1D in the works, they are soon way behind.

I think it's better to get rid of the mirror altogether, than using impressive sounding and probably expensive  contraptions to work around the limitations. A seismograph does sound impressive, but it's a workaround adding to the parts count in the camera.

Akira

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Re: Question on Leaf-Shutters
« Reply #17 on: January 16, 2017, 16:18:31 »
Frankly I would doubt if the sensor used in Fuji GFX and Hasselblad X1D offer sensible difference compared to, say Sony 42MP full-frame sensor.

The Sony sensor used in GFX and X1D is only 44x33mm in size.  The difference between this sensor and a full-frame sensor is smaller than that between a full-frame sensor and an APS-C sensor.  Also, the 44x33 Sony sensor can put out 14bit data and thus is not compatible with 16bit Opticolor+.

Phase One offers larger sensor (53.7x40.4mm) for IQ3 series which puts out true 16bit data and compatible with 16bit Opticolor+.  The difference between the IQ3 sensor and a full-frame sensor should be sensible.
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Erik Lund

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Re: Question on Leaf-Shutters
« Reply #18 on: January 16, 2017, 16:33:50 »
Apparently the mirror-less think that the removal of a mirror makes it up for an inferior sensor, dynamic range and bit depth,,,

BTW there is a complete range of lenses that fits the Phase One.
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David H. Hartman

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Re: Question on Leaf-Shutters
« Reply #19 on: January 16, 2017, 23:06:19 »
There is a shutter efficiency issue with leaf shutters. How much effect is determined by how fast the shutter can open and close. The shutter will always open fully but the faster the shutter speed the less time the shutter will be fully open. The shutter acts as an aperture that varies as it opens and closes. Older, slower, larger leaf shutter would be most likely to show this issue. It's only an issue for high shutter speeds. I never worried about shutter efficiency because I didn't shoot medium and large format transparencies at high shutter speeds. Also the shutters in lenses for the Hasselblad 500 series had top shutter speeds of 1/500th but in reality they were more like 1/350th which would compensate for the shutter efficiency.

The effect of shutter efficiency is to decrease exposure. For still life slower shutter speeds would normally be used so shutter efficiency would not be an issue.

Dave Hartman
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bjornthun

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Re: Question on Leaf-Shutters
« Reply #20 on: January 17, 2017, 00:11:08 »
Apparently the mirror-less think that the removal of a mirror makes it up for an inferior sensor, dynamic range and bit depth,,,
No, they do not think such rubbish, as the global moderator suggests.  >:(
Quote
BTW there is a complete range of lenses that fits the Phase One.
Good for Phaseone.

There's no point in further participation here.

David H. Hartman

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Re: Question on Leaf-Shutters
« Reply #21 on: January 17, 2017, 00:35:37 »
If I was to venture into 'medium format' I would go all in for a Phase One XF 100MP, not just because it's Danish, which I'm quite proud of, but because it works,,, and it is a significant step up compared to even the D810,,,

Sensor 53.7 x 40.4 mm, 16 bit, 15 stop dynamic range, ISO 50,,,

It also features build in Focus Stacking,,,

Expensive, yes but please make an inventory and compare the two totals,,,

Were I at the least a demi god I'd already own a Phase One XF 100MP with a macro, normal, half and double lens but as a mortal of the peasent class I can only dream.

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pluton

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Re: Question on Leaf-Shutters
« Reply #22 on: January 17, 2017, 01:47:49 »
There is a shutter efficiency issue with leaf shutters. How much effect is determined by how fast the shutter can open and close.

We might as well mention the other efficiency issue with leaf shutters.  It is the increased exposure effect when using very small aperture stops.  Since the little f/16 hole is fully uncovered longer than, say, a f/4 hole, it is fully exposed longer than the f/4 hole.  The effect is small, less than a stop as I recall, and only had to be seriously considered when using finicky, contrasty slide films.
Keith B., Santa Monica, CA, USA

Akira

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Re: Question on Leaf-Shutters
« Reply #23 on: January 17, 2017, 01:54:13 »
I've heard that the very efficiency issue "functions" like the apodization filter (because the peripheral area is "dodged") and makes the bokeh somewhat smoother.  Of course, that would depend highly on the balance between the actual speed of the leaves and the shutter speed.
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Roland Vink

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Re: Question on Leaf-Shutters
« Reply #24 on: January 17, 2017, 02:22:40 »
If the shutter is close to the aperture blades near the optical center, a semi-closed shutter shouldn't affect exposure into the image corners any more than a stopped down aperture does. When the aperture is wide open and the shutter speed is very fast, a significant fraction of the exposure will be while the shutter is opening and closing - not fully open. In that case the shutter is acting like a stopped-down aperture, so the exposure will be less than expected (shutter efficiency as previously mentioned), and the DOF will be greater than expected.

On the other hand, if the shutter is far from the optical center, the  image corners could experience significantly less exposure than the center. This effect will be most noticeable when shooting at wide apertures, which is exactly were optical vignetting is strongest, vignetting increased further due to the shutter!

fish_shooter

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Re: Question on Leaf-Shutters
« Reply #25 on: January 18, 2017, 00:17:04 »
An interesting discussion thus far. At one time I owned a fairly large Hasselblad system, most items were bought in the 70's and 80's so we are talking a while back! I agree with much that has been said. I suspect that shutter efficiency is one of the reasons Zeiss developed the 100mm Planar lens that was optimized for wide-open shooting at infinity, i.e., for aerial photography. As well there is no distortion due to different sides of the frame being exposed at different times (e.g., high shutter speed with FP shutters). In contrast the 80 Planar for SLRs (I have owned both the Hassy and Rollei versions and they behave the same) is quite poor wide open. They need to be set at least to f/5.6, better yet at f/8. Most of the Hassy C lenses needed to be stopped down a bit. Many were best around f/11. As well there is a tiny button below the winding crank on the side of 500C and later related bodies - This triggers the first part of the lens cycle and flips up the mirror. After this, the sound of the Compur shutter and Prontor shutter on later lenses is quite quiet. It is possible this new Hasselblad will be this quiet - we need to wait and see/hear. A quiet camera will be useful for certain shooting scenarios such as inside churches. I saw a top view comparing the new Hasselblad to the new Fuji and other cameras on the net a few days ago but can't seem to be able to find it now - it shows the Hassy as being much thinner than the Fuji. Thus the H might be a good choice for a field camera. Slower lenses could also mean lighter weight lenses...

One of the main disadvantages of the Hasselblad V system is that one was limited to the lenses provided by Hasselblad. The only 3rd party item that I recall was a teleconverter (I did not own this). About the time that the Nikon Ai lenses came out Hasselblad introduced the 2000 series cameras with focal plane shutters. I eventually bought two of them. They were not problem free. I once had to send a camera with a stuck on lens to Hasselblad for repair - it was stuck in the middle of the lens cycle. However, the cool thing was adapting other lenses. For me this included having a Bronica focusing mount for the Nikon super tele lenses modified to mount on a Hasselblad. I had owned the 500mm Tele-Tesssar lens but had a bad experience with it - it broke in two at the shutter while I was on a sailboat shooting a regatta in Puget Sound - not a good time for this to happen!  As well the 500 had chromatic aberration that could be seen in a transparency without much magnification.  The lens was only f/8. So I was eager to try out alternatives! I was able to find all 4 focal lengths of the Nikon super teles. The barrel of the focusing mount as well as the Hasselblad mount and sides of the body preclude these lenses from covering the full 54 x 54 mm of the format. Just a wee bit of the corners are cut off. No problem for any rectangular crop, however. I sold the 400 and 600mm but still have the 800 and 1200(ED version!) as well has the modified focusing mount and AU-1. It will be interesting to see what gets developed for the new Hassy in the way of lenses and how good they are. I suspect we will see more in the way of lenses from Fuji due to the focal plane shutter and the within company advantage of development and manufacture (i.e., vertical integration).

David H. Hartman

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Re: Question on Leaf-Shutters
« Reply #26 on: January 18, 2017, 01:37:16 »
Focal plane shutters: something to consider in regard to leaf v. focal plane flash sync.

The Nikon D800 and D300s both offer X-sync up to 1/320th or 1/250th second (both options) but one is not home free. With a speedlight such as an SB-700, 800, 900 or 910 there will be shading (not black band clipping) at the top of the frame at full and half power. By dropping to one quarter power or 1/200th at full power the problem goes away. I've seen this shading problem with a Norman 2000 XP also. The problem is inherent vice as Canon owners report the same. It is easiest to see on a light background such as a white seamless. I'll try to post test photos when I get home.

The issue here is the total shutter travel time and the T.10 flash duration. I'm searching for trough boxes in the "attic" for a proper explanation. It may be that the first curtain has started closing clipping the tail of the flash while the rest of the frame gets the full benefit of the dieing flash pulse.

Dave
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Erik Lund

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Re: Question on Leaf-Shutters
« Reply #27 on: January 18, 2017, 09:01:40 »
With all the new flash sync-types like for instance Elinchrom High Sync (HS) there is no need for leaf shutters at all.

On D810 or D5 the Elinchrom flashes (select types, HS) sync with up to 1/8000 without any problems at all!
Erik Lund

simato73

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Re: Question on Leaf-Shutters
« Reply #28 on: January 18, 2017, 16:02:42 »
According to Fuji Rumors the new GFX will come with an optional (and quite expensive) adapter for Fuji 645 lenses for Hasselblad.
This has electronic contacts with the lens and you can choose whether to control the aperture from the body and use the camera shutter or use the lens shutter.

http://www.fujirumors.com/leaked-images-specs-fujifilm-gfx-lens-adapters-wcltcl-x100-ver-ii/
Simone Tomasi

Les Olson

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Re: Question on Leaf-Shutters
« Reply #29 on: January 19, 2017, 11:27:43 »
The flash sync speed is the whole ballgame? No other benefits for those of us who don't use flash? It makes me wonder if I should be getting a Fuji GFX.

The leaf shutter is useful in two situations.  What they have in common is the use of flash mixed with ambient light.

One situation is where you want to use flash to stop motion while keeping the ambient lighting high.  The duration of a flash is very short - 1/1000 sec or so.  The fact that the camera shutter is open for 1/200 sec or so does not matter if there is no other light, because the only exposure will be during the flash.  But if there is enough other light to produce exposure the whole time the shutter is open you get ghosts - partial images of the moving subject.  So leaf shutters enable you to stop motion either outdoors in daylight or in the studio while having enough ambient light to see what you are doing.

The second is when you want to do take pictures outdoors in bright light with fill flash, but you want a large aperture for shallow depth of field - which will cause extreme over-exposure if the shutter speed has to be 1/200.  Of course, you can save a few thousand dollars and use a neutral density filter with a focal plane shutter, unless the dim viewfinder image is unacceptable.   

There are examples of both at https://fujilove.com/flash-fuji-and-leaf-shutters/