Film Medium Format Cameras

[Kayaker72]

Don't know much about film but I wonder how the size of silver halide crystals compares to pixels?

Smaller.

At least according to this link. Silver halide crystals are 0.2-2 um. Where the "dye cloud" is 1-10 um. Pixels on the R5 are 4.39 um, for example.

That is a good way to look at it. Silver halide crystals are in the wavelength of light size.

BTW....that seems to be a pretty comprehensive article. It looks like it may answer a lot of my questions. I've just scanned it for now, but in talking about resolution, they seem to be settling on the 1.6:1 contrast values I've seen represented from MTF curves, not the 1000:1 contrast. For Velvia 50, for example, that would be 80 LP/mm or 22.1 MP FF equivalent/60 MP 645 MF equivalent.

[HDNitehawk]

3&5 > 4, 6 and 7
The detail of the A is intricate.
1 is sharper than 2, this could have been operator error .

[Kayaker72]

3&5 > 4, 6 and 7
The detail of the A is intricate.
1 is sharper than 2, this could have been operator error .

Yep. I am not sure what happened. When you zoom in at 100%, it looks back focused. But even that isn't 100% sharp. It was shot wide open (f/1.9) which isn't as sharp at f/2.8, but it is pretty good. I did do some tests with Lens Align, but they may have also shown some user error as f/1.9 seemed pretty good, but two shots at f/2.8 were both back focused.

I am very impressed with the Mamiya 645 1000S I bought. It's all very basic, but it does have many features (timer, mirror lockup, multiple exposures, DoF preview, etc). It even has AFMA in terms of these three screws you can adjust that change the height of the focusing screen. But, with film, as f/1.9 seemed on (maybe a hair backfocused) and f/2.8 was clearly backfocused, I am thinking I test it again with Roll #2, then shoot landscapes at narrow apertures for the rest of roll #2, and adjust only if I see conclusive test results....in a couple weeks. And then if I have to adjust the AFMA, I have to figure out which way to turn the three screws. Take more photos...wait a couple more weeks and hope I didn't turn the screws the wrong direction....

[HDNitehawk]

I am very impressed with the Mamiya 645 1000S I bought. It's all very basic, but it does have many features (timer, mirror lockup, multiple exposures, DoF preview, etc). It even has AFMA in terms of these three screws you can adjust that change the height of the focusing screen. But, with film, as f/1.9 seemed on (maybe a hair backfocused) and f/2.8 was clearly backfocused, I am thinking I test it again with Roll #2, then shoot landscapes at narrow apertures for the rest of roll #2, and adjust only if I see conclusive test results....in a couple weeks. And then if I have to adjust the AFMA, I have to figure out which way to turn the three screws. Take more photos...wait a couple more weeks and hope I didn't turn the screws the wrong direction....

It might be cheaper to MF.

[Kayaker72]

It might be cheaper to MF.

Haha...yeah....the problem, that is MF!

My fault as I called it AFMA. Really, it is focus screen adjustment. All MF. No AF. But if the path to the focus screen is different than the path to the film, the focus even via MF will be off. So Mamiya has these 3 little screws where you can adjust the height of the focus screen.

Really, it pretty cool. That said, huge win (IMO) for digital where you can focus on the actual image plane.

And, actually, getting back to all the scanning of old photos I am doing. It really does highlight to me, capturing memories, many things are not critical. But, wow, do the images of my family when they were young that were in focus stand out from all the images that are soft or outright oof.



Getting back to the resolution of film discussion for a second. I am putting it on hold for a bit as I want to see some more actual images that I've taken. Bottom line is that I am seeing arguments made that are all over the place, literally FF equivalents to 16 MP, 22 MP, 80 MP, and even HIGHER (usually made by film aficionados). And, I was only curious. This wasn't a burning question for me.

But, a couple of takeaways:

• Until I do my own testing, I am thinking the 16-22 MP is likely the "film" resolution equivalent.
• The resolution of film may not be as direct as digital. If nothing else, you have the silver halide crystals that will affect tonality that are sub-micron in size (and highly variable), smaller than current digital pixels. For color "dye clouds" are similar size to larger than current digital pixels. And then you have layers of each (seems 6 to 9 layers was typical with higher grade film having more layers). Taking a step back, it may not lend itself to resolution tests using high contrast ISO charts.
• Film stock has been improving (Fig 15 in the link). One of those obvious things but trying to take data that is decades old may not be representative of "modern" film. And many of the comparisons I am reading are a decade, or more, old.
• Lenses have improved. People, especially a decade ago, keep putting a heavy penalty on resolution because of the lens quality. But...over the last decade lenses have improved immensely. One could argue that this illustrates that digital is higher resolution as lenses did not need to be higher quality with film. But I wonder if this goes back to my first bullet. At the micron level, film's strength may not be resolving high ISO test charts. But, digital, excels in that department.

So, I have some rolls of film. I'll shoot them. We can already see a bit of a difference on the "A". Let's see. That sounds like more fun than reading more of these articles.

[Kayaker72]

Turns out fotodiox has this tilt/shift adapter for most medium format lenses to the RF mount. Mine arrived today.

I was happy to have it confirmed that focus peaking in the R5 works with the adapted Mamiya lens and, a quick test:


Mamiya 645 80 mm f/1.9 @ f/1.9 no adjustments:

Same settings, tilted down:

I played around with the shift feature as well, I did not notice any strong vignetting.

Could be a nice way to get wide aperture, longer focal length tilt-shift lenses. Keith Cooper did a review.

Fotodiox also offers a "Rhino Cam Vertex" where you mount the adapter to a tripod, then pivot the FF camera mounted to the adapter in a circle taking 4 images. These images can then be stitched together to replicate the image circle of various MF lenses. Interesting idea.

[Kayaker72]

A quick update. I have a couple more rolls of film that I am developing, so I'll share a few more film/digital comparative examples when I get the film back...in a couple week

But I am mostly done with this side project and, unexpectedly, it has been a lot of fun and very interesting.

First, I picked up the Mamiya 645 1000S at my local shop really just to give "medium format" a try. The body was $300 and the 80 f/1.9 C lens was $330. So my initial investment was low and I figured if I didn't like it, I could resell and not loose much at all.

But, I decided to expand my Mamiya kit and last week picked up the 45 f/2.8 C and 150 f/2.8 A. In terms of FF equivalence, this gives me a 28 mm, 50 mm, and 90 mm lenses with equivalent DoF ranging from f/1.2 to f/1.7. With shipping, this was another $715, so I am in this a total of $1,345.

I did this for a couple of reasons:

1. I did figure out that these lenses could be adapted onto the RF mount using the Fotodiox tilt/shift adapter giving them added flexibility for future use.
2. I am enjoying shooting film more than I thought I would. The jury is still out on if there is an IQ difference, but being methodical, thinking of each shot, trying to make it count, and when you get it, you are done because you only have 15 shots to a roll. I've enjoyed that process. With digital there is no cost to additional images, I take a lot of additional images and I am always looking for that next image. I've enjoyed being more methodical and limited because there is a cost to additional images and you are limited to a number of exposures.
3. Image quality. Jury is still out on if I think one is better over the other. But the jury is completely in on the fact that film and digital are simply different. What I originally referenced in that Slanted lens shoot out, I've seen multiple times. Simply put, Film handles over exposure exceptionally well but does not handle (i.e. not recoverable) underexposure and digital is the exact opposite. Perhaps the most comprehensive test is here where they did a +/- 10 stop (so 21 images) comparison of film and digital and concluded, for this scene film and sensor, digital had a range of -6 to +2 stops and film had a range of -2 to +10 stops. If you watch, you may disagree with any number of things (I do, for starters, I wouldn't call this dynamic range, but exposure latitude), but the trend has always been there, digital handles recovering shadows much better than film which handles whites/highlights much better than digital.
4. OVF. I do not mind the R5 EVF. But even going to the 5DIV, I enjoy the OVF. But this is next level. I actually laughed out loud when shooting last week as it was just after sunset and my Mamiya OVF was brighter than the scene with such amazing detail. It was fun.
5. Resolution. These are not 20-30% changes in linear resolution/detail. I've had a version of the chart below for digital for years but have added film sizes to it during this exercise.

Simply put, even my Mamiya 645 has 2.7x the surface area of FF. But, start getting into larger MF sizes, 6x7 or even 6x9, they have 4.3x and 5.6x the surface area of a FF sensor. Now, Fujifilm claims to have film that can resolve 160 lp/mm. Most people seem to think high end film is more like 80 lp/mm. I found several references to MF and LF lenses resolving 40 to >80 lp/mm. So, using 80 lp/mm, larger MF formats are ~100 MP equivalent while LF is equivalent to 320 to 1,280 MPs. You can see back in the days before photoshop why MF/LF had the mystique they did, it was the only way to get more detail.

Quick side note, but I am very curious about some of the 645 images taken compared to my R5. The linear resolution, if 80 lp/mm is accurate, should not be that different as 56 mm x 80 lp/mm x 2 pixel/lp = 8,960 on the long axis while the R5 is 8,192 pixels. The difference in MP in the above table is more about different aspect ratios (645 MF is taller).

So, jury still out on the actual comparative IQ of Film. But Film has it's own characteristics and I've enjoyed shooting it.

I am good having that tool in my photography toolbox.

I do consider myself lucky to have the Mamiya 645 1000S. It seems like a great little system. The glass is excellent. No light meter, so I may pick up a pentaprism that has one (camera is modular, so I can just swap out a pentaprism with light meter for the waist level viewfinder) that would be another $240. Overall, very much worth $1,345 to me.

As I've learned and looked, I've of course wondered about other systems. In particular, I wonder if a handheld Mamiya 7ii (range finder with 6x7 format) would get more use for size/weight travel. People rave about the glass. It is popular and out of production so it is actually getting pretty expensive. There is also the Mamiya 6 and Fuji also has some rangefinders, but do not seem to have the same acclaim as the Mamiya's.

I could have stayed with Mamiya and more recent 645 bodies had AF, metering, and exchangeable backs. Seem like good systems, but I did hear them referred to as "plasticy" which is one reason I felt good about picking up the mostly all manual and metal 1000S available at my local shop. There are also the RB and RZ systems that are 6x7 from Mamiya, but the bodies/lenses are much larger than the 645. I've heard reference that they are better as "studio" lenses.

Also, if I do like the IQ out of the images I've created and if I was to go back and start from scratch, I might end up with my Mamiya or I may very well have spent a bit more money and gone with Hasselblad 500 series. It is probably the most similar to what I have in terms of size, weight and form factor, but shoots 6x6, has Zeiss lenses (better than Mamiya?), and, maybe most importantly, the system is still somewhat alive. Sure Hasselblad has gone digital but they do have a digital back that would mount to their 500 series bodies. So, you could have a body, both film or digital backs, and swap out as desired. Granted, the digital backs are >$5k, and a different size than the film. On the Mamiya side, while 6x6 is larger, but as soon as you crop, you are likely back to something around a 645 and I do not typically shoot square images, so I would be cropping. There are Phase One (who bought Mamiya) and Leaf digital backs from some Mamiya cameras, but not the 1000S.

Before doing anything more, I want to evaluate more images that I've created. Then, we'll see.

[HDNitehawk]

I think your exercise would make a better photographer. It is so easy to get in the habit of taking multiple pictures to get the right mix for what you want. If you are only allowed one shot you have to think the process through.

It appears to me that anything you produce with the film camera would be for print display. If you digitize and scan your picture is a representation of the original and may not have the same "feel" of the original. Any comparison you present on the computer will be a picture vs a picture of a picture.

Some of the items you mentioned, couldn't you control yourself if you set up your own dark room and processed your film and prints yourself?

Sounds like a fun exercise regardless.

[Kayaker72]

Hi Rick,

I have wondered the same thing. Taking a picture of a picture is one thing for digitizing old family images, as it is great just to get it in a modern format and share with family. But, if we really want to get the most out of film, staying analog may make a lot of sense.

I am not sure I see doing prints myself. But I could see processing the film myself. Actually, it seems that is what many do and it would cut down the wait time for film from weeks off to a lab to a few hours or overnight. Of course, it is more work.

But, diving into the limitation: scanning. First off, I've read a couple of times that good scanners are actually only getting ~2400 dpi even when you set them higher and even though their "native" resolution is rated higher. The V850 camera used for transparencies is reported to be 6400 dpi, but people who have run tests claim to not be able to achieve that. But, using those two values and 36 x 24 mm film, 1 inch = 25.4 mm, so 2400 dpi becomes 94.5 dpmm and 6400 dpi becomes 252 dpmm. Converting to pixels assuming 1 dot = 1 pixel and you get 3,402 x 2,260 =7.7 MP to 9,072 x 6,048 = 54.7 MP.

So, really, even if 35 mm film is capable of 22 MP, by scanning at home we might be crippling film's actual resolution. The scanner may be the limitation. And, if this tests out, you have to ask if it would be better to stay completely analog?

I've only played with the math on this one after reading a few things. This is something I plan to play with at some point if I do get into film and scanning at home. For now, for my family archival project, I am just scanning at 2400 dpi to 3200 dpi. If I find some images that I want to do something with, I might send those out for higher end digitization (wet mounted drum scanner, etc).

[Kayaker72]

Ok. I have had my next round of film returned and I have worked up a few images for comparison. Much of this is for my benefit, but I am posting here in case anyone is interested.

This is not meant to be some sort of film vs digital as if there was a winner. They are different. But I am seeing a place for film in my kit.

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