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05-02-2020, 09:43 PM - 1 Like   #1
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medium format and dimensionality

Bought the 645Z a couple of months ago and have taken over 1000 shots. A high percentage of my images portray a heightened sense of depth. They look 3D. Even relatively flat scenes with a foot of depth often appear more dimensional.

See this depth once in a while on the K-1, but not often on close up shots. My 3 amigos (31, 43, 77) are supposed to excel at depth. I've used the 645Z with mostly the DFA 55 2.8. Has anyone else noticed the Z reproducing depth more often? If so is it the Z, the DFA 55, or both?

Work interferred with my shooting time on the K-1. I've shot the 645Z almost as much in two months as the K-1 in a year. Perhaps I'm being unfair to the K-1?
Thanks,
barondla

05-02-2020, 09:59 PM - 1 Like   #2
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Yup. I've noticed the same thing since I first saw pics from the 645D, and I've never shot medium format. I even use the same term that you do - "dimensionality".
05-03-2020, 01:15 AM - 2 Likes   #3
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MF is not just about resolution.
05-03-2020, 02:02 AM - 2 Likes   #4
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QuoteOriginally posted by barondla Quote
Bought the 645Z a couple of months ago and have taken over 1000 shots. A high percentage of my images portray a heightened sense of depth. They look 3D. Even relatively flat scenes with a foot of depth often appear more dimensional.
QuoteOriginally posted by zapp Quote
MF is not just about resolution.
The resolution does add a hyper-realism relative to APS-C or FF, but I believe the other big factor that creates that 3D sense of depth is the increased contrast in sharpness between the resolution at the focal point and the bokeh fore and background.

That inherent reduction in depth of field becomes so problematic with large format, using tilt shift helps to overcome the lack of depth of field.

05-03-2020, 05:48 AM - 3 Likes   #5
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I think MF has a superior ability to separate planes in our pictures, thus creating this 3D impression. APS-C particularly produces flat-looking images where everything appears to be in the same plane of focus. (Grand Canyon picture taken with Pentax 645Z + FA 45-85 mm f/4.5 @ f/11).


Last edited by RICHARD L.; 05-03-2020 at 06:57 AM.
05-03-2020, 05:58 AM - 3 Likes   #6
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Hi,

This is one reason I recently opted for a 645D over a higher res Nikon than my Df. Back in 2003, I had a 3-camera Kodak setup, all digital backs on film bodies. Two were Nikon F5 based, one an APS-C 2 MP Hi ISO (400-6400) and the other an APS-H 6 MP Low ISO (80-400). The third is more relevant to this thread: A Contax 645 with a 16 MP digital back.

The Contax back was a 36mm x 36mm sensor of the same fabrication as the 6 MP APS-H one: The Kodak M6 process. The entire point here is that even with the smaller image area of the Pro Back sensor, the Dimensionality (I do like that term) was quite apparent.

So, fast forward to 2018 and the Nikon Df. This is Full Frame 135 format and offers a useful ISO range better than the two old F5 based Kodaks. And, resolution equal to the Pro Back on the Contax 645. I kept the 6 MP APS-H unit as I still have some use for it, but let the other two go. But, I missed having something medium format. There was little point in keeping the old Pro Back, so that rig went to a collector.

What to get to add to the Df? I considered a few of the higher res Nikon bodies, but the bulk of my Nikon lenses are from the film era and go back to 1970. They all work just fine on the Df, but if I went 36 MP or higher in Nikon I might well find myself buying a lot of newer glass as I found the limits to my antiques. That'd get really expensive really quickly. What to do?

I looked at the Fuji offerings, and might well have gone for the 50s. But, what else is out there? It doesn't take much looking to spot the Pentax 645 system. And, there it was: a 645D for a good price from a camera shop. And, some decent lenses, also at good prices. The icing on this cake, for me, is that the 645D has one of the last of the Kodak CCD sensors. So, being Mr Kodak Digital still, that was an easy choice. And, the lenses are useful should I get a 645Z or even something Fujifilm GFX. For me, medium format is mostly a manual focus operation anyway.

With this choice, Pentax over Nikon, I also gain some other benefits from the larger format.

Stan
05-03-2020, 06:10 AM - 3 Likes   #7
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Is this the sort of effect you're talking about?

Two random snaps from yesterday with exactly the same combination. Already posted in the 55mm club, but I think they warrant a re-post in this context.



05-03-2020, 07:00 AM - 1 Like   #8
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I think the extra dimension is also a product of the pixel size and pixel pitch of the larger sensor. With bigger pixels there is more room for the colors blend together which gives the image that extra depth and tonality. At least that's how I understand it and apologies if I haven't explained myself properly.

It's early and I'm still on my first cup of coffee.

05-03-2020, 11:46 AM   #9
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QuoteOriginally posted by Alex645 Quote

That inherent reduction in depth of field becomes so problematic with large format, using tilt shift helps to overcome the lack of depth of field.
Yeah, even in MF film the longer focal lengths can often be more DOF challenged. In LF, the movements only help if you don't have tall objects in the foreground you also want in focus. Then it becomes pure stopping-down to get DOF like any fixed plane camera; otherwise, the movements can do more than overcome the DOF challenge due to the large focal lengths. The movements can augment the DOF (the Schempflug principle).
05-03-2020, 11:52 AM - 2 Likes   #10
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This is a hotly debated topic!

I'm among those who think that there are qualities to digital medium format that are not found in FF of equal resolution, and not just depth separation.

Those who have done more rigorous testing (none of them Pentaxians, so you won't see them here....) have found no differences that are appreciable.

I'm left to think that here we are possibly talking about "other factors" not yet tested for, or something that is quite hard to quantify, but detectable as a quality more subjectively (and synergistically).

To truly compare, the experiment has to be extremely apples to apples, and I think that is very hard to impossible across different formats, bodies, lenses, and stable testing procedures in the field (I don't think the studio environment is conducive to this particular test...unless it's a wondrously large studio...).

My personal conclusion is that it's a lot like good taste in art---cannot be measured, but that does NOT mean it's not there.
05-03-2020, 12:58 PM - 1 Like   #11
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Isn't this simply a question of tonality. It is a well known property in analogue photography that a larger format gives (can give) better tonality. But I think it is less well known among digital users. The differences in sensor size we are talking about here are relatively small so the effect is less visible anyways.

See also
Why are FF images so much more pleasing than APS-C? - PentaxForums.com
05-03-2020, 03:00 PM - 4 Likes   #12
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Here are two examples from my 645 (film) with a 75mm which is about equivalent to the 645D with a 55mm.
05-03-2020, 09:49 PM - 1 Like   #13
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I'm with Tex in that I don't think it's merely selective focus.

But I recall my first experience with medium format versus 35mm, when a guest pro to my college's camera club showed some 11x14 prints. The medium-format print had been made using a Yashica Mat 124, and the 35mm shot using a much higher-end Nikon F. The 35mm shot was crisp and clear, with excellent resolution and detail. So was the MF shot. But the MF shot had a quality of smoothness the 35mm shot lacked, and the difference was not subtle.

Consider these two images, scanned from film with a Minolta film scanner close to 20 years ago:





One was made using a Canon Elan with a 14mm lens, and the other with a Kiev 60 and an Arsat Fisheye--both extreme wides on their respective formats. Neither use selective focus. Both photos were made at the same location on the same day, but not at the same time by some minutes. I'm not saying what film I used, but film was all I had at the time. Both images are cropped but not severely. It is true that both were interpreted in different ways, but only to go in the direction the images already pointed to.


I think I could point to the smaller format image from across the room, even at this resolution (which is too small to demonstrate any differences in resolution). No fair tracing the URLs


I will conclude by recommending to Barondla to avoid ever making images with a 4x5 or larger camera. It could be ruinous.

Rick "who might get the Sinar out in the coming weeks if the lockdown continues" Denney
05-04-2020, 08:35 AM   #14
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Why Medium Format Is So Gorgeous (It's About More Than Resolution)
QuoteQuote:
it's often easy to detect medium format images even when viewing on the web. It has a certain something, a signature look that is often recognizable but hard to articulate. It comes from the lack of perspective distortion. This makes photos look more natural, closer to what your eye sees in the real world. Let's say you're shooting on a 6x7 medium format camera with a 50mm lens. If you compare your images to a 35mm camera, also with a 50mm lens, you will notice the difference in field of view. Your medium format pictures will actually see what a 24mm lens on a 35mm camera would see. Simply put: the larger the film format, the wider angle your lenses become compared to 35mm.

The key point as a result of that difference is that even though the field of view is wider, the geometry, or "look," of the 50mm focal length remains. You don't get the exaggerated perspective that wide angle lenses usually produce on 35mm cameras. In that regard, medium format mimics how your eyes actually see the world, at least more so than the smaller 35mm size. The effect is even more apparent with large format 4x5, 5x8, or 8x10 film. You can shoot an extremely wide scene but it will have the "real-world" look of a lens with a longer focal length. The subject remains flat and not 'stretched' out.

thoughts?
05-04-2020, 09:45 AM - 3 Likes   #15
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I can’t agree with the visible paragraph. I’ve made photos on various formats with the exact same field of view (meaning: same camera location and same ratio of focal length to format diameter, correcting for differences in format shape), and perspective rendering is identical. Perspective rendering is all about camera position. Magnification is about focal length, and field of view is about format.

By comparison, I mean a wide range of formats, from 28mm on APS-C to 160mm on 4x5.

Rick “light moves in straight lines with respect to perspective” Denney
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