35mm Film — Negative Format Oddities…

[radi(c)al_cam]

Im blind in one eye and although i haven't specifically tested it mm seems to fit well to what i see. Obviously it could just be me wrongfully thinking that but usually what i see i usually get something very similar with a 28mm

Dear Jake,

I guess you're accustomed to use your healthy eye to a much larger extent than people with two healthy eyes.

Very probably you use the entire field of view (even the parts where colours are invisible), while people with two healthy eyes use just the centre (where all coulours can be seen); cf. here: https://commons.wikimedia.org/wiki/File:Netzhautlk-polarp.jpg

 

[mich rassena]

There were quite a few scale focus and fixed lens 35mm rangefinders sold with 45mm lenses. And I've seen quite a few 52, 53, 55 and 58mm lenses, and the 50s are only nominally 50 while the film is only nominally 24x36. So ultimately, does it make a difference?

 

[tunalegs]

There were quite a few scale focus and fixed lens 35mm rangefinders sold with 45mm lenses. And I've seen quite a few 52, 53, 55 and 58mm lenses, and the 50s are only nominally 50 while the film is only nominally 24x36. So ultimately, does it make a difference?

Not really.

55mm and 58mm were popular for SLR use because they gave (apparent) 1:1 viewfinder magnification without the need for an actual 1:1 viewfinder, as well as eased the design constraints of trying to make fast glass that would clear the reflex mirror. This actually brings up an interesting point about how little this really matters. There are some SLRs out there with 1:1 viewfinders, Mirandas, Exaktas, and such. They give 1:1 "life size" viewing with 50mm lenses. They also don't. Because the size of the image changes as the lens is focused - moved closer or further from the film. Guess what? Angle of view also changes slightly when this happens. So there's little point in being absolutely precise matching the focal length to the diagonal of the negative. If you focus on something very close to the camera, the viewfinder image appears larger than real life, because the lens is further from the film plane. It'd drive one crazy if they got hung up on this issue.

I think it'd be much stranger if somebody created a format and then a lens around a diagonal measurement, rather than any other more pertinent considerations.

 

[Dwig]

... Because the size of the image changes as the lens is focused - moved closer or further from the film. Guess what? Angle of view also changes slightly when this happens. ...

Correct. How much change occurs varies depending on lens design. With "classic" designs where focusing is accomplished by moving the whole optical cell forward there is a modest change at first, as you move away from infinity, and it becomes significant as you get to close distances and approach true macro ranges.

With systems that focus by altering the spacing of elements it is extremely difficult to calculate the change. Most of these designs function by altering the focal length of the optical system, reducing the FL as you focus closer. The classic front cell focusing lenses all work this way. Modern internal focusing lenses can engage is other optical gymnastics as well.

Even with a precisely known focal length it is dubious to do these calculations with any excessive precision, especially when dealing with film rather than digital. The full image area is almost never imaged on a print, even when the print size matches the image's aspect ratio accurately.

 

[Huss]

Can't say I've ever seen a 43mm lens.

Regards, David

There's this one—and it's a good one!

43mm lenses are perfect for those who find 42mm too wide, and 44mm too long.

 

[Ko.Fe.]

50mm?

Everyone knows a 35mm is the standard lens. Why else would it be called 35mm film 😀

No, it is 135 film, so, 135mm lens!
😀

 

[mpaniagua]

...

Beyond that, the number printed on the lens is usually nominal, rather than a precise measurement of the lens' actual focal length. There are a lot of 50s, which I suspect are somewhat shorter or longer than what is indicated on the front ring...

Leica even put that on some of it lens. My Summilux 50 is actually a 51.4mm 🙂

Also, I find the 40/1.4 lens on my Olympus Pen F (Film one) very comfortable, even more than 50mm on full frame 35mm.

Regards.

 

[zuiko85]

Another thing to consider. Although 35mm film started out being used in VF/RF type cameras and the usual 'normal' focal length was 50mm. But, with the rise of 35mm SLR type cameras 50mm or even 55mm was probably the shortest focal length that could be made to clear the swinging mirror without resorting to more complicated retrofocus designs. That could be another reason for the 50mm as 'standard'.

 

[Dwig]

...with the rise of 35mm SLR type cameras 50mm or even 55mm was probably the shortest focal length that could be made to clear the swinging mirror without resorting to more complicated retrofocus designs. ...

"Normal" and "standard" have different meanings. True "normal" lenses for 35mm full frame would be between 35mm and 43mm depending on whether you reference the conventional machine printing mask printing a modest size borderless print from a mounted slide or whether you hand print with black edge from a filed out negative carrier in either the enlarger or scanner. "Standard" is what was normally sold with the body. Actually, we should stop using "standard less" as "kit lens" has replaced the term in modern jargon unless we are specifically discussing purely historical times.

The "50mm" lenses that were standard (read: the "kit lens") on Leica RFs, and LTM compatibles, along with the Nikon S series bodies were actually 52mm. The Contax RF lenses were also not actually 50mm, though slightly different from the Leica/Nikon convention. Nikon also sold a 35mm lens as a "standard" kit lens option on their later S series offerings, at least on the SP.

True Planar designs up to f/2 were no problem at "50mm" (usually they were actually 52mm). Faster version required 55mm, as a rule, until the early 1960s. True Sonnar designs, as opposed to "Sonnar" branded lenses by Zeiss that sometimes deviate significantly from the original design, originally required a minimum of 58mm to clear any decent sized mirror. Later versions using newer glasses drifted down to 55mm, though they differ a bit in design from a true Sonnar.

 

[michaelwj]

No, it is 135 film, so, 135mm lens!
😀

Touche 🙂

That explains why my Leica has 135mm frame lines then!

 

[David Hughes]

...Beyond that, the number printed on the lens is usually nominal, rather than a precise measurement of the lens' actual focal length. There are a lot of 50s, which I suspect are somewhat shorter or longer than what is indicated on the front ring.

Hi,

FWIW, the passport with the lens on my FED shows its true focal length, Leica made the only other lens with a known, rather than nominal focal length.

(Edit) And I've a Jupiter-12 with its true focal length shown as 34.84mm on the passport.

Regards, David

 

[David Hughes]

Actually, we should stop using "standard less" as "kit lens" has replaced the term in modern jargon unless we are specifically discussing purely historical times...

Hi,

This worries me as most people used to modern digital cameras seem to regard kit lenses as being the entry level lens and will eventual replace, or plan to replace, it with something better. To me something better suggests the worst about the standard one. You didn't get that with (say) the Olympus Trip 35 and dozens of others.

I'll add that expression to analogue meaning film in my list of things screwed up by digital...

Regards, David

 

[Dwig]

...

I'll add that expression to analogue meaning film in my list of things screwed up by digital...

Regards, David

Almost no one remembers that the original Sony Mavica electronic still camera was analog as were the TV and other video cameras of the day.

I remember when the old analog cell phones were replaced by newer digital models. People, particularly those that sold and promoted the new models, didn't want to call the new ones "cell phones" despite the fact that they still used cellular technology switching from one tower to another and frequency hopping. They just digitally compressed the audio to lower the transmission power requirements, among other advantages. I notice that over the some 2 decades since the death of the analog models people have drifted back to "cell phones".

 

[Godfrey]

The simple answer is that what is considered a normal lens is almost entirely a matter of convention. It's based loosely on field of view being close to human vision which happens to be pretty close when the focal length equals the diagonal of a format, but convention rules over calculation.

G

 

[Spavinaw]

Dwig made an extremely pertinent point I'd like to expand on. He said, "The full image area is almost never imaged on a print...". Considering 35mm negatives, if you're printing 4X5 or 8X10 your useful negative area would only be 24X30mm with a diagonal of 38.4mm. If 5X7, then your usable negative area would be 24X33.6mm with a diagonal of 41.3mm. If 11X14 it would be something else, and so on. Therefore, if you want to shoot with a 'normal' lens having a focal length equal to the diagonal of the negative, you are going to have to know beforehand the size of the print you are going to make with that negative!! I'm afraid I'll never be able to do that. How about you??

 

[tunalegs]

Dwig made an extremely pertinent point I'd like to expand on. He said, "The full image area is almost never imaged on a print...". Considering 35mm negatives, if you're printing 4X5 or 8X10 your useful negative area would only be 24X30mm with a diagonal of 38.4mm. If 5X7, then your usable negative area would be 24X33.6mm with a diagonal of 41.3mm. If 11X14 it would be something else, and so on. Therefore, if you want to shoot with a 'normal' lens having a focal length equal to the diagonal of the negative, you are going to have to know beforehand the size of the print you are going to make with that negative!! I'm afraid I'll never be able to do that. How about you??

Or just print full frame.

But then, some would have you think you also need to consider what distance the print will be viewed from. If the print is viewed from a long distance, you "should" select a longer lens. This is why movies are generally shot with relatively long lenses, because most of the audience sits pretty far back from the screen. If viewed from a short distance, a wide lens should be used, etc.

It's actually a bit more complicated than that, but I'm not feeling pedantic enough to get into the details. Nor do I entirely buy into the idea, because ultimately as long as the photographer is happy with the perspective they've chosen, it is arguably the right perspective.

 

[radi(c)al_cam]

I guess we can conclude:

Regarding still photography on film, the «normal lens length idea» — that it should be the diagonal of the negative format — is an obsolete construct. (?)

Nevertheless, even today many «prime»*lens focal lengths, particularly the larger of course, are still the — anachronstistic? — lenghts of other (sometimes outdated) negative formats.

E.g., the 10.5cm or 105mm length: originally the «normal lens» for 6cm x 9cm (and nearly exactly the diagonal of ~55mm x ~90mm), was and still is a common length both for 6x6 and 24x36.

Hence I presume it's still intriguing to know these figures, even if they're somehow relics 😉

 

[David Hughes]

The normal focal length is the one that sells the most cameras or else the one that is used the most.

So it could be 55, 50, 42, 40, 35,30, 28, 24 or even 21mm. I wish I hadn't mentioned the 30mm as it will push up the price of the Lydiths...

Regards, David

 

[radi(c)al_cam]

So it could be 55, 50, 42, 40, 35,30, 28, 24 or even 21mm. I wish I hadn't mentioned the 30mm as it will push up the price of the Lydiths...

Dear David,

there's no chance that true US Americans will accept that a 30mm lens is a useful or a collectible one.

I mean: 30mm — that's devil's work, evidently. Only Communists, Atheists, Free Masons, Catholics, and similar dangerous people would ever buy a thing that is in real money 1 plus 23/128th of an inch … 😉

 

[David Hughes]

Dear David,

there's no chance that true US Americans will accept that a 30mm lens is a useful or a collectible one.

I mean: 30mm — that's devil's work, evidently. Only Communists, Atheists, Free Masons, Catholics, and similar dangerous people would ever buy a thing that is in real money 1 plus 23/128th of an inch … 😉

Hi,

It's a good thing that true Americans are a minority in the USA then...

Regards, David