Don't know much about film but I wonder how the size of silver halide crystals compares to pixels?
Don't know much about film but I wonder how the size of silver halide crystals compares to pixels?
Smaller.Originally Posted by Joel Eade
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.
Last edited by Kayaker72; 02-07-2022 at 03:01 PM.
3&5 > 4, 6 and 7
The detail of the A is intricate.
1 is sharper than 2, this could have been operator error.
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....
It might be cheaper to MF.
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....
Haha...yeah....the problem, that is MF!It might be cheaper to 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.
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