« Your Camera Is Too Slow | Main | Open Mike: A Short Break (Blog Notes) »

Friday, 05 May 2017

Comments

Protective glass is the enemy of the lens-collector unless said collector sticks to highly telecentric lenses with copious exit pupil distances. The Sonys use 2mm of glass on their sensors, while Leica seems to have settled on 0.8 mm cover glass thickness on the current Ms and SL. So those should be the best choice for the collector of lenses from all eras and all makers. Expensive? Yeah, but what is that to the serious lens collector?

But there are limits. Jim Hughes gets lovely results from his Canon rangefinder 19mm on a Fuji X-Pro2. The Canon 19 is sort of a poor man's SuperAngulon, an extreme design that almost touches the imaging chip. But my copy, perhaps not in as pristine condition as Jim's, vignettes severely at full frame on my SL.

The Sony A7ii also has a thick glass in front of the sensor, that's why Leica wide angle lenses look like crap on it and why some owners go to the trouble of replacing it.

It's not like everyone wants a Fujifilm camera. In fact, according to CIPA, Fuji is dead last in mirrorless camera sales. (Which, incidentally, account for roughly half of DSLR sales volume.) Fortunately most consumers are wise enough to sway away from such expensive, yet flawed cameras.
And this lump of a camera is not really what I'd call 'desirable.' Atleast not in my book. Compare the 50S to the Hasselblad X1D: the latter is svelte, and its evocative design is simply gorgeous. A far cry from the rather bulky, all-black Fujifilm camera. And I have no reason to believe the Hasselblad is any worse than the Fujifilm. Sure, the Hasselblad is more expensive, but since we're in a 'what if I won the lottery' mode, that's not an issue.

Mike, on the Fuji X- series and lenses other than Fuji. I ditched the excellent 14mm Fuji for the equally excellent 12mm Zeiss offering. At the wide end the two extra mm does make a difference. Both are very good. No problems with either lens, just wanted a bit wider without going to a zoom.

Ya know Mike, they have this at LensRentals now...Just sayin"

I always took it as a sign of ineptness on Sony's part that people rather use old manual focus lenses rather than their OEM offerings. Isn't it the case that the camera manufacturers make a higher margin with their lenses? At least traditionally. With Sony they introduce new models at such a rapid rate that perhaps they simply want to churn camera bodies....

Yes I too often wonder how the knight of the wind blown castle is not the ruler of an establishment of imaging goods, having more in his private vaults than the vaunted Samy, my liege, Earl of Angeles.

Mike, I appreciate your worldview. I am often amused by the way you ponder GAS.

Yaaaawn!!
Give us more shots of the farm!
My most desirable camera of this moment is on its way to me: a Yashica 66.
Hey, it doesn't need an extra piece of glass in front of the sensor.
And it has a bigger sensor too!
PLEASE, Mike, more photos!!!
Regards,
David

Always thought its major 'problem' was its clunky, brick like appearance from a company renowned for its innovative design.

For a brief while I subscribed to the Facebook GFX page and saw "billions" of photos made with adapted lenses, all jpegs, all sized and modified for Facebook, all of which touted how fabulous they were. I found myself overloaded with "fake news." I knew they couldn't be as wonderful as touted. Thanks again to Lloyd and his analytical approach. It really does make sense that lenses designed without allowance for a specific cover glass might not work as well as hoped. The emperor has been revealed. He has no clothes. It makes no sense to spend US$6,500 on a body and then attach inferior lenses, what a surprise!

A few dozen old lenses and a Sony A7 is fun! More fun than a barrel of monkeys I am sure, since a can of air and a microfiber cloth is usually adequate for lens cleanup.

I wonder though about the use of Fujifilm GFX to Hasselblad H adapter.
The camera, adapter, and lens are all made by Fujifilm as is the Hasselblad H itself. It seems like the best of all worlds solution to get a selection of leafshutter lenses and perhaps Fuji designed the GFX with the H lenses in mind.

I still enjoy shooting my Koni-Omega Rapid 200 (6x7) - the big negatives are a joy to look at. But I must confess, I sort of struggle to see the benefit of trying to squeeze legacy format lenses onto such a heavily cropped 44x33mm format.

Even 645 lenses will have a 1.3x crop factor, and 6x7 lenses will a 1.6x crop.

Don't get me wrong, I even enjoy using old 135 film SLR lenses on M4/3 sensors, so there's an even bigger crop. But at least those film lenses are relatively compact, lightweight, and very inexpensive.

With MF lenses, on the other hand, trying to get anything adapted in the wide or normal category on the Fuji 50S would cost a small fortune for dubious results.

But hey, if the cover glass doesn't affect anything longer than 85mm, those are probably the only lenses that actually make sense to adapt anyway, so maybe it's totally a non issue!

Strange that Fuji announced a view camera adapter to be used with the GFX as the "medium format" back if it has that problem?

Mike: I’ve no idea who that guy in the White City is — but as you know I've been using the GFX-50S for about a month now. There are many reasons to "covet" this camera and its native lenses if you need extremely detailed larger-than-35mm frames. While no camera is perfect the GFX-50S might truly be THE game-changer among its peers in the emerging larger-than-full-frame / cropped medium-format sensor camera realm.

But that’s a larger essay. Let me get straight to the point here: adapted lenses versus Fuji's native GF lenses. Fuji’s GF lenses are excellent. I have the 63mm and the 120mm. (Jeremy’s 32–64mm is very scarce at this writing.) But if you need anything wider or longer, as I do, using adapted lenses is your only choice right now. If you’re a Hasselblad H system owner you’re in clover, as Fuji (cleverly) offers a fully-linked H-mount adapter for the GFX. Unfortunately us Phase One/Mamiya owners aren’t yet as well-accommodated. Fotodiox makes Mamiya 645 and Hassy V mount adapters for the GFX but they’re mechanical-only. So my Mamiya 645AF lenses will only work on the GFX wide-open.

My choice has been to get good Hasselblad and Mamiya manual-focus lenses to use with the Fotodiox adapters. (These lenses have manual diaphragms.) Patient searching has produced Mamiya 35mm F3.5 and 45mm F2.8 lenses and a Hasselblad 250mm F4. Each of these lenses is probably around 30 years old yet they’re all in like-new condition. Two even came with their original packaging and documentation. And I bought each for a fraction of their original prices!

So how do these lenses compare to the Fuji GX lenses? They’re each excellent, quite snappy across their frames with good contrast. (The Mamiyas each feature the then-“new” coatings, signified by the “N” designation. The Hassy is a Zeiss lens with T* coating.) But none are quite as sharp and crisp as the Fuji’s. I do not follow “digilloyd” but I don’t attribute this difference to insider engineering or glass sensor covers. Rather, I believe it's due to thirty years of progress with lens and camera designs. I have seen this same difference in old-lens experiments with my other cameras. Achieving a crisp image on inert film is a different, less cooperatively demanding, proposition than on a large digital sensor. Each of the older lenses renders a lovely highly detailed image that actually looks somewhat more film-like than the Fuji lenses. It’s a softness of fine tonality rather than strictly that of edge definition, if that makes sense.

At least that’s my take so far after approximately 750 frames.

Mike, I can’t really do a detailed review of the Fuji GFX (there are already plenty out there). But I did promise you some practical field notes on the camera which I am currently assembling into something legible and intelligible. Coming soon!

tl;dr Fujifilm designed their system for their lenses. They don't care about enthusiasts who attempt to adapt older film lenses to their cameras. If you can afford $6500 for the body you should be able to afford the lenses. Wouldn't you buy this system for the "best quality" images?

I see Lloyd doesn't quite understand all the implications of this design: there are two.

The first (and the one he's most worried about) is slanting illumination of pixels in the corner and the impact of the thickness of the cover glass on that. This is the effect that leads to "purple corners" as rays pass through multiple pixels. You can clean it up in software (e.g. Sandy McGuffroy, of AccuRaw fame,has a program for this) but to minimize this effect you need a thin cover glass e.g. Leica which uses a very thin cover glass 0.25mm to enable it's old M mount film lenses work as well as they can on the CCD and CMOS sensors. It works well enough on "ordinary" focal length lenses but when you go very wide the ray angles of older symmetric lenses causes problems on non-monchrome sensors (note: this isn't an issue in with the monochrome Leicas -- in those you just get a bit more smearing in the corners).

You can accommodate this (as Leica do on their custom sensors) by offsetting the microlenses from each pixel: the further from the center of the sensor the more you move them towards to primary axis. If you were really clever you might even change their shape so they squint towards the axis (I don't know if anyone does this).

These slanting rays towards the edge of the image circle are not an issue as you design telecentric lenses for the platform so I rather doubt that Fujifilm do this as they will be designing telecentric lenses from the system (they have no incentive to design for backward compatibility).

The second is a (thick) flat plate adds spherical aberration into an optical system. This is not an issue for lens design for the platform that includes a thick flate plate as the designer takes account of that plate (and it's positive spherical aberration) when they design lenses. So all the lenses Fuji will make will work perfectly with this system.

You see this same design in the mirrorless micro FourThirds system which has a 5mm (and a bit) thick plate over the sensor. This was a design Olympus used in the original FourThirds DSLR cameras and retained when the introduced the micro FourThirds system so the older high quality lenses would be compatible when used on an lens adaptor.

The problem comes with older lenses designed (as Lloyd points out) for film cameras that expect no flat plate in front of the film.

Why anyone would be using Nikon FX lenses (or even other medium format lenses) on this camera is beyond me. If you can buy the body then you can buy the lenses. If you can't afford the latter then don't buy the former. In real life the people who will buy and use this camera will not be adapting lenses for it. That seems to be a curious amateur predilection (and perhaps the odd artists requiring a particular look).

Roger at LensRentals wrote a set of articles on this (Lloyd does reference it) in which measurements are made and conclusions drawn from those measurements.

https://www.lensrentals.com/blog/2014/06/the-glass-in-the-path-sensor-stacks-and-adapted-lenses/
https://www.lensrentals.com/blog/2014/06/sensor-stack-thickness-when-does-it-matter/
https://www.lensrentals.com/blog/2014/07/sensor-stack-thickness-part-iii-the-summary/
https://www.lensrentals.com/blog/2015/01/a-thinner-sensor-stack/

Another comment: Lloyd says "Thick glass might make spectral cutoff easier than too-thin glass however, as per the Leica M8 infrared leakage problem.". The thickness of the cover glass has nothing to do with IR filtration. The IR cutoff filter is a dielectric mirror on the top of the cover glass. Leica did have a weak IR filter on on some of their early cameras (the M8?). They did this for reasons I don't fully understand but they corrected that in later models.

Finally he initially said that the spacing of the cover slip away from the sensor added more problems. As a reader pointed out to him (and he corrected the text) the position of the plate makes no difference (in this case).

Caveat lector when reading Lloyd :-)

On the upside it's nice to see the technical details and design decisions behind this camera fleshed out.

[A very thorough explanation Kevin, thanks very much. --Mike]

I'm certain it's only a matter of time before several companies are modifying the GFX to use a thinner cover glass, as happened for the Sony A7-series camera bodies.

One of the blogs I check in my rounds is George Barr's. I enjoy his abstract work quite a bit. He has recently started using a GFX and has several posts discussing the camera and perhaps more importantly pictures produced with the camera. Maybe something to tide you over until Ken mounts his charger and come to tilt at your windmill.

http://georgebarr.blogspot.com

In my limited knowledge, I think Fuji is the only manufacturer to have used a cover glass with a significant air space behind it, adding 2 more air to glass transitions. They designed their lenses to account for that, thus had to know the problems it would cause for 3rd party lenses, yet still chose to feature an adapter for H lenses. (I don't know if the Fuji adapter has any corrector optics)
One of the reasons the camera was attractive to me, was that I own the 17,24, & 90 Canon T/S lenses, all superbly sharp and able cover the Fuji sensor with some movements left.
But that doesn't seem like a viable option.
I believe the Sony AR7II sensor is a sandwich and probably handles third party lenses better.
So I'll wait to see more actual users report.

Under real world shooting conditions, I'm hard pressed to squeeze out every bit of 36MP goodness from my D810. And I've spent a lot of time and money chasing wunderkind optics like Zeiss manual focus lenses and perfecting my shooting techniques, but, if truth be told, I keep getting many great shots handheld on old Nikkor AIS glass where 36MP sensors are already all that is necessary.

Sometimes I reach 36MP FX sensor perfection in a captured image, especially with the Zeiss glass and a sturdy tripod, but more often than not, my image captures are not perfectionistically perfect in regard to maximum image sharpness achievable with a 36MP sensor. And typically, it's not the camera sensor limits at all, but the optics and camera vibration which limits the result.

So, I ask myself, "what actually happens in real world shooting with a digital medium format camera like the new Fuji, with so little MP increase over my Nikon D810, that we are splitting hairs on how bit a print you can make?"

Then, too, there are the other metrics like high ISO noise, dynamic range (I really mean exposure latitude), etc., to consider. However, at the end of the day, I think DOF at the chosen focal length necessary for desired field of view and at corresponding optimal apertures for image sharpness is perhaps the largest deciding difference between MF and FX digital formats today. I print big, and sensor noise is almost never the limiting factor. It's subject matter (i.e., whether high spatial frequencies need to be rendered successfully or not) and blur due to camera and subject movement which limits final image enlargement capability.

Given these constraints, and given that FX is going to peak in total image quality somewhere in the 50MP-80MP range for some years to come, I'd be looking for 100MP+MP out of an MF digital camera for me to even consider leaving FX for MF. And my pockets aren't infinitely deep. The price difference can't be 4:1 or more for twice the pixel count when evaluating MF versus FX. Perhaps, the Fuji GFX version 2 will be the ticket needed to truly differentiate MF versus FX sensor formats. The GFX isn't there yet, IMHO.

". . . in the emerging larger-than-full-frame / cropped medium-format sensor camera realm."

Ken's descriptor is accurate, but awkward. Mike likes to define things.

What's the TOP approved naming convention to be?

FF+
MF-
Mutt

FF sliced in half is half-frame. 645 is really half-MF, 6x9 cut in half. To me, 6x6 is the smallest that really deserves the MF name.

Using frame height, to minimize format proportion differences, 44x33 is 37% larger than FF, and 45% smaller than 6 cm wide formats, so I'd vote for FF+.

The Phase One 53.7x40.4 format could then be MF-

"I always took it as a sign of ineptness on Sony's part that people rather use old manual focus lenses rather than their OEM offerings."

You may misunderstand what's going on for many people. I have several friends who want nothing more than a good FF back for their beloved old manual FF glass.

They are essentially brand agnostic for the "back", sometimes rabidly brand loyal for the old glass, and completely uninterested in the AF lenses for the back. Many were/are using Canon DSLRs, the almost universal recipient for MF lenses, as digital backs. As the only mirrorless FF body, with it's short register distance, the A7 line is the new universal recipient.

Focusing aids in live view make these lenses much easier to use well on mirrorless than DSLRs

The addition of IBIS makes the Sonys the only real choice for lovers of old glass who want digital backs. Various problems such as stack thickness, cover glass and other imperfections leave many unhappy and/or undecided.

Various patents lead to rumors and hopes for another player to get into FF mirrorless. Should that happen, with internal design more favorable to MF glass and as good/better IBIS, these hordes* will abandon Sonys like hot potatoes.

Me? I like crappy old glass with interesting flaws, LensBabies, soft focus lenses, old Nikkor Soft filters and such for the Alt parts of my photography. My A7 is perfect for that. I don't care about IBIS or IQ effects of stack thickness. I can't imagine what I would do with a Sony AF E-mount lens, well, sell it.

* Well, . . .

Funnily enough, I am considering purchasing an X-Pro2 and a Voigtlander 35mm f/1.4 to throw on it instead of an XF lens. Maybe it's crazy, but it seems like a nice way to have that roughly 50mm, manual focus rangefinder experience and hopefully learn something more about photography. The only thing holding me back is that my battered little old Canon isn't holding me back as it is.

I used to covet the Pentax 645Z with the same sensor. If I was going to buy that sensor now I would go for the Hassleblad X1D version, a much more elegant design and size. Yet I agree that the 50s is desired by more people than the Pentax or Hassleblad, probably due to the popularity of the Fuji X line of cameras.
Sony is already promoting a 100mp sensor in 33x44mm size, so I would expect these 3 companies to announce 645C, GFX 100S and X2D cameras for Photokina 2018 (C is for 100, get it?). I would wait for those if I was getting into medium format.
Last month I hit the shops to buy a new camera with a budget of 450 euros. I found a new, in the box, Panasonic GX7 with 14-42mm lens on closeout for 397 euros. I added 50 euros of insurance and now I am trolling e-vay for lenses since this is my first micro four thirds camera. The GX7 is an ergonomic masterpiece in every way (I have small hands).
It will probably be another 5 years before I can afford a new camera in the same price range, so all this medium format talk is purely theoretical for me, but I can safely say that if there is one guy who could blow all of his lottery winnings on photo gear that would be me!

Mike, you don't REALLY want this camera, do you? It's not stabilized.

Mike

One important use for adapted legacy glass that is a reason to not use Fuji lenses on a Fuji camera is camera movements.

On Sony A7-series cameras, you can use the excellent Canon TS lenses with a Metabones (or similar) adapter. Adapting medium format lenses to full frame sensors with tilt-shift adapter(s) is also a viable option on Sony.

For APS-C, Fuji doesn't make tilt-shift lenses, and I haven't seen them on the Fuji APS-C lens road map. I wonder if they'll ever make a series of T/S lenses for the GFX.

If you need camera movements, and you're a Fuji XF shooter, then legacy glass is your only option. I'm currently doing that with Olympus OM lenses on a Fuji X-T2 and am quite pleased with the results. (I also have a nice set of excellent Fuji glass for when I don't need movements.)

Some of the legacy glass that's out there is exceptionally good, even in comparison to modern lenses. I'm not even talking about Leica! I simply can't believe the quality of images that are produced with the humble Zuiko 50/1.8. Even shifted 8mm on a Fuji X-T2 it's extremely sharp and contrasty. Plus -- as a nice bonus -- the apertures on Olympus OM and Fuji X lenses turn the same way, and you can set the Fuji lenses to focus in the same direction as the Olympus OM lenses, so you don't have to think which way to turn each time you switch lenses!

The data I;ve seen indicates the cover glass issue is moot.

Jim Kasson has a non-commercial, ad-free blog where he rigorously evaluates and tests new cameras and lenses that interest him. For about a month Jim published results from numerous adapted lenses along with other technical aspects of the GFX 50S.

Non-Fujinon lenses work quite well on the GFX 50S. But the Fujinon's (especially the 120mm lens) always work better. Looking at Jim's results, it's clear the cover glass is a non-issue. To be complete, there might be some optical designs that are more affected than others. But clearly there's going to be a lot of useful non-Fujinon lenses.

Here's a link to Jim's summary.

http://blog.kasson.com/the-last-word/fujifill-gfx-50s-summary/

This is why I love micro4/3: I have yet to find an adapted lens that doesn't work a treat on these cameras!
Yes, sure: they become manual.
Oh, hold on: they were manual to start with?...
Still the best decision of my digital camera life!

The comments to this entry are closed.