35mm Camera's equivalent resolution in Megapixels

Neilmack

Neilmack

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A how long is a piece of string question perhaps.

How does the resolution of a good quality film camera & lens with a fine grained film equate to digital resolution? Years ago we talked of lens's resolution in lines per millimetre. How does does compare to modern metrics?
 
I can't remember what values film gave, but the right camera and lens can give fairly astonishing resolution: https://opticallimits.com/sonyalphaff/965-zeiss55f18?start=1

FWIW I'd say my 24MP A7 probably out-resolves my Bronica ETR (645) outfit using 100ASA film, and if the film speed and sensitivity are bumped up then very much so.
 
Here's another piece of string for you. Is the resolution of the lens and film you mean the resolution on the film - in which case we're talking slides - or the resolution after it's been reduced by the imperfections of the enlarging lens, the scanner optics or the slide projector lens?

It's relatively simple to calculate the resolution on the film given lens and film resolution individually. You can also relatively easily calculate the resolution of the sensor, and taking account of the Nyquist limit calculate the resolution you'd get from a perfect lens.

Lines per millimetre when assessed do depend on the contrast of the subject, and subjectively where the person assessing the figures decides that the limit has been reached.

Dare I also add that you are rather vague as to film format? If you compare a subminiature film camera with digital, you will be disappointed with a print from the film in a straight compare. Trying again with a 32x40 inch print from a 10x8 film camera compared a digital camera, and the tables will be turned.

In my experience with a Sony a7r1ii, digital beats 35mm. Move up to 6x7, and digital is better than film in colour, but to my eyes, film wins in black and white. Move up to large format, which I only shoot in black and white, and I wouldn't even bother trying to compare...
 
I read a piece on Luminous Landscape years ago and they said something along the lines of the Canon 20D threatening 35mm film with some aspects being superior and the 50D giving them the level of detail they got from 35mm film.

Persistent Googling may get anyone who's interested to that piece.
 

Comparison of digital and film photography - Wikipedia

en.wikipedia.org en.wikipedia.org

TL;DR- the above suggests a fine grained 35mm negative has a resolution equivalent to about 20 million pixels, others suggest it is much lower. It is chalk-and-cheese though, film is an analog medium so effecetively the "bit depth" of film is infinite where as digital cameras are 8 or 12 bits.
 
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Back in the day when I shot film.. the quality was generally pretty bad I thought. I used 35mm and generally Fuji or Kodak. Even prtined out to 4 x 6 never looked great, I rememebr the first digital camera (Nikon D50, OR Canon D30) to be far better... IMHO!
 
I've just found that article I posted about above...

luminous-landscape.com

Canon 50D Milestone

Canon 50D Milestone - Luminous Landscape
luminous-landscape.com
 
stickytape said:
Back in the day when I shot film.. the quality was generally pretty bad I thought. I used 35mm and generally Fuji or Kodak. Even prtined out to 4 x 6 never looked great, I rememebr the first digital camera (Nikon D50, OR Canon D30) to be far better... IMHO!
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My experience as well.

I was and am still just a "happy snapper" and just used whatever was cheap usually Konica and Agfa earlier on. Nearly all the prints were poor - just a few sets from local camera shops were good - "Colour Centre" in EP and "Miller and Palin" in chester - both now defunct.

However, I have been scanning our holiday, friends and family etc snaps in just so we can look at them conveniently on tablets etc and what was in the original negs is nothing like the prints. They are so much better - certainly fine on a tablet or a 15 inch MBpro.
 
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Intersting
greyowl said:
My experience as well.

I was and am still just a "happy snapper" and just used whatever was cheap usually Konica and Agfa earlier on. Nearly all the prints were poor - just a few sets from local camera shops were good - "Colour Centre" in EP and "Miller and Palin" in chester - both now defunct.

However, I have been scanning our holiday, friends and family etc snaps in just so we can look at them conveniently on tablets etc and what was in the original negs is nothing like the prints. They are so much better - certainly fine on a tablet or a 15 inch MBpro.
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Interesting! from memory I just had them devleoped at a local camera store. I was never bowled over, dspite the using top notch Kodak paper allegedly. I typcially used a Nikon F5 and various zooms. Without doubt the ones from the digital were a billion times better. However, that may well be in that you can leanr quicker - byt
 
The quality of prints I was getting back was the reason I went digital. I had been resisting but the poor results coming back coupled with the snotty notes to look after the negatives I'd never taken out of the packet (so they're not my hairs, spots and marks) did it for me. I went back very briefly but I can't see myself doing film again. At the time I assume they'd cut costs to try and compete with digital. Whatever the reason the quality nosedived.
 
woof woof said:
The quality of prints I was getting back was the reason I went digital. I had been resisting but the poor results coming back coupled with the snotty notes to look after the negatives I'd never taken out of the packet (so they're not my hairs, spots and marks) did it for me. I went back very briefly but I can't see myself doing film again. At the time I assume they'd cut costs to try and compete with digital. Whatever the reason the quality nosedived.
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My experience too (early 2000s).
My last few attempts with film (personal not pro*) gave utterly terrible prints, nowhere near the quality I’d been getting 10 years earlier.

* my last few pro film jobs were perfectly acceptable but I was paying a fortune for the privilege.
 
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Phil V said:
My experience too (early 2000s).
My last few attempts with film (personal not pro*) gave utterly terrible prints, nowhere near the quality I’d been getting 10 years earlier.

* my last few pro jobs were perfectly acceptable but I was paying a fortune for the privilege.
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This will have been 2003 for me. After taking the negatives in 3 times to get them redone and still getting prints back with the same problems but in different places I just gave up and bought a digital camera.
 
To be fair, the C41 processing was, in my experience, pretty good everywhere - UK and abroad.
Print quality varied a lot - the best from those specialist camera shops I mentioned and almost anywhere we used in the far east was OKish.

I have had about 5 or 6 print sets done in recent times. Asda used to have in-store film processing until 2017 ?? just £2 a roll to develop and their standard prints were pretty good as well. The only place to really trash my undeveloped film was Max Spillman - the developing was OK but they got light leak that foxed the first frames and they couldn't even cut the film properly . Tried different camera and different film stock to test them - exactly the same. The two sets of prints I had were among the worst I have ever received. I got my money back and a load of Timpson vouchers but they never accepted responsibility.

It was about that time that I got a scanner which I needed anyway for B&W stuff I develop. No interest in returning to the challenge and horror ( for me ) of home darkroom wet printing that I did in the 60's.

B&W, even on small format 35mm, does, as most know, give much higher resolution ( if that matters ) than consumer colour - with FP4 and HP5 plus. I haven't even tried the ultra fine grain films / development you used to be able to get.
 
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6mp. That was the figure Kodak put on 35mm Kodachrome in the very early days of digital. It's not something you can calculate, only compare with like for like images, very carefully taken and viewed side by side to minimise the multitude of variables that can skew things. It's not easy.

This is why estimates, and that's all they can be, often vary. But if you look at the most careful comparisons from reliable sources, 6mp is not far out.

Given how damn sharp a good 35mm film image can look, it rather begs the question of why we're so obsessed with ever-more megapixels. The law of diminishing returns has got a lot to do with it, in that say doubling megapixels does not mean double the final output resolution (nowhere near actually), but IMHO marketing and psychology has a lot to answer for.
 
There's no doubt that the image quality has moved forward since the days of 6mp DSLR's but that may not be down to pixel density. Some do love the cropability you get with todays high mp count cameras.
 
HoppyUK said:
6mp. That was the figure Kodak put on 35mm Kodachrome in the very early days of digital. It's not something you can calculate, only compare with like for like images, very carefully taken and viewed side by side to minimise the multitude of variables that can skew things. It's not easy.

This is why estimates, and that's all they can be, often vary. But if you look at the most careful comparisons from reliable sources, 6mp is not far out.

Given how damn sharp a good 35mm film image can look, it rather begs the question of why we're so obsessed with ever-more megapixels. The law of diminishing returns has got a lot to do with it, in that say doubling megapixels does not mean double the final output resolution (nowhere near actually), but IMHO marketing and psychology has a lot to answer for.
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Because digital isn't film, and smaller pixels can make for cleaner tonal and colour transitions, to a degree. But I KNOW you know that. :)

When I printed regularly there was a big jump in quality between 35mm and medium format even at 10X8. I remember well being disappointed with an image shot on a 100ASA slide film (can't remember which Kodak film it was now, probably Ektar) when I printed it 10X8 on Cibachrome and it simply didn't have anything like the detail I'd expected. If 35mm is the equivalent of 6MP then MF would be about 12MP, and for 10X8 that's an acceptable minimum to me.
 
Although photographers have always argued about "image quality" I'm pretty sure that few photographers could actually agree on what it is. In the 1960s I made some pictures of a company's staff on Tri-X in a Nikon and enlarged them to life size. They were in the company's reception area for years. The grain was decidely obvious at three feet but the customer liked them, which to my way of thinking is all that matters.

A travelling exhibition of wildlife photography that I visited a few years ago had five foot wide prints from Canon 10D and similar 6MP cameras. They looked very nice to me...

Wildlife photography exhibition at Winslade Park DSC01097.JPG
 
AndrewFlannigan said:
Although photographers have always argued about "image quality" I'm pretty sure that few photographers could actually agree on what it is. In the 1960s I made some pictures of a company's staff on Tri-X in a Nikon and enlarged them to life size. They were in the company's reception area for years. The grain was decidely obvious at three feet but the customer liked them, which to my way of thinking is all that matters.

A travelling exhibition of wildlife photography that I visited a few years ago had five foot wide prints from Canon 10D and similar 6MP cameras. They looked very nice to me...

View attachment 316295
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Whilst you’re correct about not obsessing about the image being much more important than IQ.
You’re completely wrong to suggest that photographers can’t agree what ‘image quality’ means.
There’s been a standard for measuring image resolution for decades in lpmm and the vast majority of ‘photographers’ understand the principles.
 
The biggest prints from 35mm film I've seen were by Mario Testino, mostly of Princess Diana, at The National Portrait Gallery. Huge things ten feet high. With crisp vibrant colours that looked spectacularly good from the end of the corridor but close-up they completely fell apart, just a load of blobs, and a good reminder about how important viewing distance is to the whole concept of sharpness (and depth-of-field).

And that's one of the 'problems' with digital in that it's so easy to hit the 100% button on screen and not realise you're now looking at a truly massive enlargement maybe several metres wide at point-blank range. By the same token, everything looks sharp when it pops up small on the camera's LCD or on a smartphone.

While I could sometimes get good sharpness from 35mm film, it was never easy (eg slow Kodachrome printed on Cibachrome) and prints were relatively small 10x8in even when compared to a typical PC monitor. In contrast, good sharpness with digital seems almost effortless - accurate focus is easy and if shutter speed is too slow, just bump the ISO. I was never happy with sharpness from 35mm at ISO400 and for professionals 6x6 or 6x4.5cm medium format was the norm - Mamiya, Bronica, Hasselblad. I always lusted after a Pentax 6x7. The jump in image quality, even at higher ISO, was just in a different class.
 
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