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05-20-2016, 02:29 PM - 1 Like   #1
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Rating Film Lenses for the K-1

I would like to suggest a rating system for judging the resolution of old film lenses for use on the New K-1. The new sensor is capable of resolving about 110 Line Pairs/mm. The very best 35mm color film could resolve about 50 lp/mm. Old film lenses generally exceeded the resolution capability of 35mm color film by a small margin; say 55-65 lp/mm - since there was little point in having lenses sharper than that - as that sharpness couldn't be seen in photographs.

My idea is pretty simple: take a picture made by a lens mounted on a K-1 in a Photoshop type editor and start blowing it up. As long as you can see new detail in the enlargement - continue. However when no new detail is appearing and things as a result start looking "soft" - stop and note the magnification percentage. That number becomes its K-1 rating. Good film lenses will have ratings in the 50% to 65% range.

To put this in perspective a 50% lens is capable of making a picture which will fill a 55" 4K screen with detail. Making a 20"x30" print from that picture would result in a print that one could bury one's nose in and be happy with its sharpness.

Here are a couple of (reduced resolution for the web) pictures taken with a Takumar F 70-210 f4.5-5.6 lens on a K-1 at f6.3. I rate this lens as a 50% K-1 lens.

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05-20-2016, 04:14 PM   #2
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Just tested the FA 24-90 f3.5-4.5 at f6.3 and f8. K-1 ratings of 67% and 69%.

---------- Post added 05-20-16 at 06:47 PM ----------

Just confirmed my statement that a 50% rated lens would have no problem filling a 4K 55" screen with detail; I took the originals of the two Takumar pictures I posted in this thread and viewed them as JPEGS on my 55" 4K - they looked rich and detailed.
05-20-2016, 05:25 PM   #3
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QuoteOriginally posted by HoustonBob Quote
The very best 35mm color film could resolve about 50 lp/mm.
I've see 35mm colour film rated up to 200 lp/mm and b&w even higher. This of course can be debated for ever and ever! .

Also depends on who and how the film was tested, if it's cheap consumer film or the finest 35mm movie stock..................

Phil.
05-20-2016, 06:04 PM   #4
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QuoteOriginally posted by gofour3 Quote
I've see 35mm colour film rated up to 200 lp/mm and b&w even higher. This of course can be debated for ever and ever! .

Also depends on who and how the film was tested, if it's cheap consumer film or the finest 35mm movie stock..................

Phil.
The highest resolution 35mm color film was Kodachrome 25 - at 50 lp/mm. None of the C-41 or E-6 films could match it. The only 35mm film with higher resolution was black and white - which did have resolution up to 160-200 lp/mm. I think you may have gotten those confused.

Movie stock is very grainy and of lower resolution compared to still picture film. You can get away with a lot of grain in a movie because the grain changes with each frame of film - which makes the grain very hard to see. Still pictures on the other hand have to possess finer grain - since what ever grain there is does not change as one looks at the picture - making it more visible.

Potentially the early three filter Technicolor process had the potential of very high resolution - since it used black and white film - but the B&W film available at that time wasn't very high resolution.


Last edited by HoustonBob; 05-20-2016 at 06:14 PM.
05-20-2016, 06:20 PM   #5
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Huh? Provia 100f is 135 lp/mm. Ektar 100 is well over 100 lp/mm as well. Not sure if it easy ever available in 35mm, but Ektar 25 was something like 200 lp/mm.
05-20-2016, 06:25 PM   #6
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Let's see some of those FA 24-90 photos!

QuoteOriginally posted by HoustonBob Quote
Just tested the FA 24-90 f3.5-4.5 at f6.3 and f8. K-1 ratings of 67% and 69%.

---------- Post added 05-20-16 at 06:47 PM ----------

Just confirmed my statement that a 50% rated lens would have no problem filling a 4K 55" screen with detail; I took the originals of the two Takumar pictures I posted in this thread and viewed them as JPEGS on my 55" 4K - they looked rich and detailed.
So far I have seen only a few on the K-1. Your 67=69% seems . . . Good.
05-20-2016, 06:40 PM   #7
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QuoteOriginally posted by HoustonBob Quote
The new sensor is capable of resolving about 110 Line Pairs/mm. The very best 35mm color film could resolve about 50 lp/mm
Good film can over resolve the 35mm digital sensor on DSLR by quite a lot, if you have a good scanner.
A DIGITAL CAMERA WOULD HAVE TO BE 156 MEGAPIXELS TO GIVE YOU THE SAME KIND OF DETAIL AS 35MM FILM.

Of course, very few user would use the max resolution power from film and usually print much smaller.

I would not worry to much about the resolving power from high end film lenses on K1. In fact, the pixel density of K1 is about same as K5. so two pictures taken at same position using same lens on K5 and k1 should look similar if viewed 100%.
05-20-2016, 06:42 PM   #8
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QuoteOriginally posted by dcshooter Quote
Huh? Provia 100f is 135 lp/mm. Ektar 100 is well over 100 lp/mm as well. Not sure if it easy ever available in 35mm, but Ektar 25 was something like 200 lp/mm.
Yes, Ektar 25 was available in 35mm.

I have shot quite a bit of Ektar 100. There is no chance that it can resolve 100 lp/mm. Its grain limits its resolution to less than 8 megapixels equivalent and Ektar 100 has the finest grain of any 35mm color film outside of Kodachrome 25. A 10 megapixel k200 shows much finer detail using the same lenses than an MZS using 35mm Ektar 100 can show - and it is not close. I have tried scanning Ektar 100 at 9600 dpi - with a scanner that can do that resolution honestly. Fine detail is simply obscured by the grain - which the scanner is capable of scanning exactly. I have also tried a microscope on it - sorry no chance Ektar 100 has that kind of resolution.

---------- Post added 05-20-16 at 08:58 PM ----------

Remember that the original Canon 1ds - the first practical full frame dslr - caused quite a stir when it was demonstrated in Popular Photography that it could out resolve color film. That was an 11 megapixel camera. 35mm Color film got left behind in resolution at that level. 14 megapixels can out resolve medium format color film. That is why most medium format photographers scrapped their film Hasselblads.


Last edited by HoustonBob; 05-20-2016 at 06:51 PM.
05-20-2016, 07:42 PM   #9
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QuoteOriginally posted by grahame Quote
Good film can over resolve the 35mm digital sensor on DSLR by quite a lot, if you have a good scanner.
A DIGITAL CAMERA WOULD HAVE TO BE 156 MEGAPIXELS TO GIVE YOU THE SAME KIND OF DETAIL AS 35MM FILM.

Of course, very few user would use the max resolution power from film and usually print much smaller.

I would not worry to much about the resolving power from high end film lenses on K1. In fact, the pixel density of K1 is about same as K5. so two pictures taken at same position using same lens on K5 and k1 should look similar if viewed 100%.

You are correct IN BLACK AND WHITE film. No chance in color film. Take any 35mm color film you want put it in an MZS use the same lenses on a K-1 and the K-1 will blow the color film away - and it won't be close. I did an awful lot of color film photography 45 years ago - it isn't even close.

The size of the grain in 35mm color film limits its resolution. Sorry that is just a fact.
05-20-2016, 08:04 PM - 1 Like   #10
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OK, I found a comparison. The film scan was 7191x4766 - very close to the resolution of a K-1. The film was Ektar 100. This is a crop from both. First the film, then the K-1. It is not even close. And don't tell me it was a bad scan. A microscope doesn't show any more detail on the negative than the scanner got. Same lens.
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05-20-2016, 09:52 PM   #11
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QuoteOriginally posted by HoustonBob Quote
The highest resolution 35mm color film was Kodachrome 25 - at 50 lp/mm. None of the C-41 or E-6 films could match it. The only 35mm film with higher resolution was black and white - which did have resolution up to 160-200 lp/mm. I think you may have gotten those confused.

Movie stock is very grainy and of lower resolution compared to still picture film. You can get away with a lot of grain in a movie because the grain changes with each frame of film - which makes the grain very hard to see. Still pictures on the other hand have to possess finer grain - since what ever grain there is does not change as one looks at the picture - making it more visible.

Potentially the early three filter Technicolor process had the potential of very high resolution - since it used black and white film - but the B&W film available at that time wasn't very high resolution.


Weren't the newer Kodak technologies used in movie film first, and then trickled down into still film? It could go both ways -- yes, you need lower resolution for the movie film for the reason you described, but also movie film is enlarged way more than a still photo would be. The grain would be apparent in movie-screen sized enlargement, but the size of a print, even a quite large one, would be much smaller.

Lee

---------- Post added 05-20-16 at 09:55 PM ----------

QuoteOriginally posted by HoustonBob Quote
OK, I found a comparison. The film scan was 7191x4766 - very close to the resolution of a K-1. The film was Ektar 100. This is a crop from both. First the film, then the K-1. It is not even close. And don't tell me it was a bad scan. A microscope doesn't show any more detail on the negative than the scanner got. Same lens.
Which lens was used for the film vs. K-1 comparison?

Lee
05-20-2016, 10:29 PM   #12
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The flaw in your thinking is that B&W film played a very large role.

One table lists Line Pairs per mm @ 1.6:1 contrast for
Kodak Tri-X 400 (2004) 65 lppm
Kodak Plus-X 125 (2006) 80 lppm
Kodak Pan-X 170 lppm

Another rates Tri-X at 50 lppm @ 1.6:1 and 100 lppm @ 1000:1 contrast
The older higher silver content versions of these films may have higher lppm.

Lenses were designed with these films in mind.

Numbers depend on contrast used, whether a scanned or examined under a microscope. The old Modern/Popular Photography tests the negatives were examined under a microscope.

Using a microscope Zeiss Camera Lens News rates Ektar 25 at 200 lppm

http://www.zeiss.com/content/dam/Photography/new/pdf/de/cln_archiv/cln19_de_web.pdf
http://www.zeiss.com/content/dam/Photography/new/pdf/de/cln_archiv/cln20_de_web.pdf
05-21-2016, 05:35 AM   #13
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QuoteOriginally posted by Not a Number Quote
The flaw in your thinking is that B&W film played a very large role.

One table lists Line Pairs per mm @ 1.6:1 contrast for
Kodak Tri-X 400 (2004) 65 lppm
Kodak Plus-X 125 (2006) 80 lppm
Kodak Pan-X 170 lppm

Another rates Tri-X at 50 lppm @ 1.6:1 and 100 lppm @ 1000:1 contrast
The older higher silver content versions of these films may have higher lppm.

Lenses were designed with these films in mind.

Numbers depend on contrast used, whether a scanned or examined under a microscope. The old Modern/Popular Photography tests the negatives were examined under a microscope.

Using a microscope Zeiss Camera Lens News rates Ektar 25 at 200 lppm

http://www.zeiss.com/content/dam/Photography/new/pdf/de/cln_archiv/cln19_de_web.pdf
http://www.zeiss.com/content/dam/Photography/new/pdf/de/cln_archiv/cln20_de_web.pdf
Ektar 100 has finer grain than the older Ektar 25 - which is why they retired Ektar 25. If Ektar 100 is limited by its grain so was Ektar 25. Yes, I was very aware of the resolution capabilities of B&W films, and yes I knew that Pan-X was the highest resolution of the generally available Kodak 35mm films. IIRC special purpose Kodak Litho B&W had a resolution rating of about 400 lp/mm. The highest resolution film of all time was the B&W film used in spy satellites; I remember that there was a picture from one of those published in newspapers about 1970 that showed Nixon getting off a plane in Moscow and you could easily tell it was Nixon even though the picture was taken from more than 100 miles up in orbit. That film has been replaced by ultra expensive full wafer digital sensors - which resolve even more. The lenses used for that kind of photography are very large compared to 35mm camera lenses - to keep them from being diffraction limited.

100 lp/mm lenses were more or less the holy grail of 35mm photography back in the day; often talked about rarely actually seen. I seem to recall that the Popular/Modern photography standards rated 40 lp/mm lenses as very good, and called them excellent if they got above 62 lp/mm.

6 megapixel digital camera had a theoretical resolution of about 42 lp/mm - which placed them in the "Very good" category - which is why the switch to digital in slr style camera occurred at the 6 mp level. Having made 20x30 prints from 6mp (Interpolated up to 54mp) - they look very good. What ever the theoretical limit of film was - the practical limits - given real world development and printing - was lower than what Kodachrome 25 achieved as a slide film. Mass production development of Kodachrome was a much more refined and exact process than typical C-41 or E-6 development. Digital is - as a practical matter - able to achieve much more of its theoretical resolution than film can.

Lee, I'm sorry I didn't see your question: the lens on both was the FA 24-90mm.

Last edited by HoustonBob; 05-21-2016 at 05:51 AM.
05-21-2016, 08:02 AM   #14
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Keeping out from the resolution discussion (I have a high end film scanner and sometimes surprised to see what i can achieve in terms of dynamic range more than detail), always interesting to see theories backed by examples. Thank you for the effort.

Last edited by FOX; 05-21-2016 at 08:11 AM.
05-21-2016, 08:59 AM   #15
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QuoteOriginally posted by HoustonBob Quote
I did an awful lot of color film photography 45 years ago - it isn't even close.
Film has changed over the years and there are a lot of new emulations that did not exist back in the early 70's when I start to shoot Kodachrome.

Today yes there are colour films that can reach 200 lp/mm and b&w up to 800 lp/mm. Things have changed, 50 lp/mm that you originally indicated is way to low for colour film. Check out a Fuji data sheet for Velvia 50 and Fuji rates it between 80 - 160 lp/mm.

Phil.
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