Author Topic: Alternative focusing screens for DSLRs - focusing on the matte area  (Read 15147 times)

arthurking83

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Re: Alternative focusing screens for DSLRs - focusing on the matte area
« Reply #30 on: January 15, 2016, 02:35:57 »
Your finding makes it clear (no pun intended) that the Optibrite from Katzeye is more friendly for MF.
.....

Actually, I'm finding it the other way around, but with a caveat.
The Katzeye I have has the two focus aides in the split prism and the microprism collar around that.
The microprism collar is quite large through the D300, which I guess is due to the smaller overall size of the screen itself relative to  the size of the microprism etching.
In this instance, my guesstimate is that the microprism circle covers roughly 1/3rd of the size of the whole screen, so that if the subject is within the 1/3rd area of the vf near the centre, then it will be in range of the microprism area.
But, the D800's S-type screen is usually more accurate if I'm manually focusing from only the matter areas(that is not using the focusing aides of the Katzeye's screen)
So if the subject is in the periphery, where you can't use the centralised focus aides of the katzeye screen, I find that the S-Type is more accurate.
All this assumes fast lenses too tho. 50 @ f/1.2, 105 @2 f/1.8, 24 @ f/2.
The 24/2 is where the accuracy difference is blurred a bit tho..
I assume that it could be due to both the f/2 aperture and the shorter focal length(which probably means deeper DOF, and hence more forgiving allowance of errors).

The 105/1.8 is the harder of the above lenses to focus, and of course the the differences between an Fx and Dx FOV also come into play.
The test target I used was a test pattern I found on the internet with stars and stripes printed on a white sheet.
I had to change distances to try to overcome any undue softness the lens may have at it's periphery too. So for the D300 I set the focus target at the periphery of the frame, and IIRC at just a very slightly longer distance(less than about 1m) whereas with the D800, I set the same target at about the 2/3rds range in the viewfinder area(ie. not right at the very edge).
My assumption here was that if the lens is less acute in it's drawing at the very edge, it'd have skewed the result a bit in favour of the D300 no matter the screen used!
While I did end up taking some images, my primary concern was on the liveview images, once I focused via the respective viewfinders.
My hit rate with the D800 setup was 'more often than not' .. in that reviewing the D800 liveview image, if I tried to tweak the image to a more focused one, it would tend to blur out of focus instead .. so I assume that focus was hit via the vf.
I do remember that the D300 usually could do with a slightly better focus point with a slight tweak more often that not, but that focus was still more than good enough tho for an image.
(the 105/1.8 has a hazy rendering wide open(up to f/2) for this area of the scene. The focus tweak was minimal, but to my eyes on the D300's Lv screen it seemed that I could do a little better.

Using the focus aides on the katzeye screen, all MF attempts were 100% spot on all the time if I allowed myself a second or so to process the scene.
In give and take situations, where only a split second is offered to get the shot(eg. a kid momentarily stopping for a photo, but with the impatience to get back to the game! ;)) my hit rate with the D300 was impacted a little, even tho it has the focus aids. I usually get it, but I still need multiple exposures to be sure to get one image at an acceptable level.


If I had the funds .. I would have jumped at the opportunity to acquire the Katzeye operations.
They certainly do have great products.
Arthur

Řivind Třien

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Re: Alternative focusing screens for DSLRs - focusing on the matte area
« Reply #31 on: January 15, 2016, 03:11:43 »
"Your finding makes it clear (no pun intended) that the Optibrite from Katzeye is more friendly for MF."
.....
.. Actually, I'm finding it the other way around, but with a caveat. ...

The Katzeye Optibrite screen is more transparent (have it in my D200, check the beginning of this thread), and I agree that would make it more difficult to determine focus with a wider aperture lens compared to one without Optibrite (although I would say my all matte D200 screen "snaps" pretty easily into focus compared to stock screen). My comparison above was to the Katzeye all-matte non-Optibrite screen, which would be my choice if available.  I am not a fan of screens with the split/microprism aids, as I think that an important point of manual focusing is to be able to focus and compose at the same time. Thus I see those screens as an entirely different class of screens.

Again, with 105/2.5 the dimness of the S-screen is not a problem. But it would be a lot more comfortable to use for focusing and framing with my dimmer lenses if it was as bright as the  Katzeye all-matte non-Optibrite, as much that if I could get one I wold be inclined to take the cost on top of the S-Screen, and in particular if the Katzeye screen later could be transplanted to the D500 if I decide to eventually go for that...
Řivind Třien

Řivind Třien

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Re: Alternative focusing screens for DSLRs - focusing on the matte area
« Reply #32 on: January 16, 2016, 06:35:40 »
Lo and behold, Katzeye had one remaining piece of the the all matte material left so I went ahead and ordered, although it is a bit crazy using even more funds on this. On the bright side (no pun intended) I got the D7100 for a good price. It also seems to me that Nikon has kept the same standard for screens from D300 up to D7200, so perhaps there could be a slight hope that the Katzeye could one day be transplanted into a D500 if I go for that. I will hold off selling the S-Screen for now.

Further comparison at f/4 and f/5.6, using the AW1 as instrument again, indicates that the D5100 all matte (non-Optibright) Katzeye is a little over 1EV brighter than the S-Screen on D7100 at f/4 and a little under 1EV brighter at f/5.6; tested with 300/4 PF with and without TC-14E, DK21M on D5100 and no magnification on D7100 to keep image sizes as similar as possible.


Řivind Třien

Řivind Třien

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Re: Alternative focusing screens for DSLRs - focusing on the matte area
« Reply #33 on: February 24, 2019, 08:59:00 »
In another thread, http://nikongear.net/revival/index.php/topic,8300.msg134877.html#msg134877, we discussed the stock focusing screen of D500 vs. other alternatives. The issue at hand is that all screens from D200 through the 7000 series to D500 are called Type B BriteView Clear Matte Mark II, but manual focus with D500 is reported to better than the other bodies with stock screen.  As I now have the D500 available, here is a comparison to my D200 Katzeye screen with Optibrite and the D7100 Katzeye without Optibrite, recorded with  the AW1 with 10mm f/2.8 lens. While I could have put the stock screens back into the other bodies, I did not want the extra risk of getting them scratched or loaded with dust, so the D500 screen is rather compared to what is presumed to be better alternatives (KatzEyes, although not available any longer). All captures were done with a DK-17M in place (the need to use a modified  adapter might be the reason the two older bodies shows more vignetting). Since these were handheld, the comparison is not valid for crispness of the viewfinder images.

First with 55mm f/3.5 at f/3.5

D200 KatzEye screen with Optibrite:




D500 stock screen:




D7100 KatzEye without Optibrite:




Then with 50mm f/1.8 at f/1.8 (this was a new setup so although I tried to keep distances and framing the same, it should primarily just be compared between cameras, not to the f/3.5 images):

D200 Katzeye screen with Optibrite:




D500 stock screen:




D7100 KatzEye without Optibrite:



Interestingly, the D500 stock screen is less transparent/more matte than the D200 Katzeye screen with Optibrite at both apertures, providing more background blurring. The effect is most pronounced with the wider aperture lens. This is quite unexpected as manual focusing improved from the D200 stock screen when the Katzeye screen was installed, and the D200 stock screen is supposed to have the same properties as the one in D500. So may be there has been variations in stock screen with similar designation, or there is something about the optics in the D500 that makes the screen provide a more realistic rendition.

Anyway my conclusion is that with the D500 screen being better than the Katzeye in my D200, there is little reason to replace it with a third party screen. It provides a very crisp and large viewfinder image with DK-17M that snaps easily into focus. It is possible that in situations with bright light and where one has to focus very fast, the Katzeye without Optibrite in my D7100 might provide somewhat higher hit rate, but the viewfinder is much darker than that of the D500 with stock screen.

 
Řivind Třien

Frank Fremerey

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Re: Alternative focusing screens for DSLRs - focusing on the matte area
« Reply #34 on: February 24, 2019, 14:51:34 »
Thank you, Řivind for the comparsion. I would be interested in whether the ground glass or the VF construction make the difference for secure manual focus operation.

After some time now with the replacement F6J type screen in the D850 which is significantly better than the original, I still rate the D500 higher in manual focus support.
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Řivind Třien

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Re: Alternative focusing screens for DSLRs - focusing on the matte area
« Reply #35 on: February 24, 2019, 22:06:10 »
Thank you, Řivind for the comparsion. I would be interested in whether the ground glass or the VF construction make the difference for secure manual focus operation.

After some time now with the replacement F6J type screen in the D850 which is significantly better than the original, I still rate the D500 higher in manual focus support.

Thanks for the comment, Frank. We would not really know for sure whether Nikon has tweaked the the ground glass properties of Type B BriteView Clear Matte Mark II screens without being able to transplant the same screen between a D200/D7000 series body and D500. However the screens are not compatible between these bodies and D500 (judged from drawings of the screens at focusing screen.com). The viewfinder optics certainly contributes to the crispness of the viewfinder.
Řivind Třien