What's the story behind 40mm focal length?

[Retro-Grouch]

Oh boy, Rob. Not the first time we've seen the M6/M7 frameline issue raised here. Big can of worms, and I'm staying away from it!

 

[p.giannakis]

I've used some 40mm lenses on various cameras but i never managed to get used to the focal lenght.

I know how much to approach my subject when i am using the 50mm or the 35mm lens - it is almost automatic how i position myself. With the 40 - althought is sounds somewhere in the middle - i was never happy with with it - most of my pictures needed croping. I am sure that if i persevered i would have gotten used to it but i was happy with my 50s or 35s lnses.

 

[Deleted member 65559]

I've used some 40mm lenses on various cameras but i never managed to get used to the focal length.
I am sure that if i persevered i would have gotten used to it but i was happy with my 50s or 35s lnses.

Likewise, If all i had was a 40mm i'd eventually get used to it, but honestly my favourite 'one lens' is a 35mm. On the other hand i never feel constrained if i have my Rolleiflex or Plaubel Makina with their fixed normal lens

 

[David Hughes]

I've used some 40mm lenses on various cameras but i never managed to get used to the focal lenght.

I know how much to approach my subject when i am using the 50mm or the 35mm lens - it is almost automatic how i position myself. With the 40 - althought is sounds somewhere in the middle - i was never happy with with it - most of my pictures needed croping. I am sure that if i persevered i would have gotten used to it but i was happy with my 50s or 35s lnses.

Don't forget the Cosmic Symbol and Smena 8 etc.


Regards, David

 

[David Hughes]

Why 40 mm?

Hi,

I guess the simple answer is why not?

Every focal length imaginable has been produced and so why not 30, 40, 50, 60, 70 etc? But they went down the 35, 50 and 90 path. Or you could go for 30, 45, 60 and 90.

And mathematicians would see 35, 50 and 85 (leading to 135) logical or perhaps 28, 50, 90, 160. (I doubt if they are obvious.)

And so on and so forth...


Regards, David

 

[ka7197]

Why 40 mm?

I guess the simple answer is why not? [...]

You did note it's a link, didn't you?

 

[nickthetasmaniac]

It never grew on me. I have the Summicron-C 40/2 and also a Pentax-L 43mm/1.9 and a Rollei 40mm/2.8. Each of these three lenses is a wonderful lens. Then why don't I use them more often? Maybe it is the awkward focal length?

As an M2 owning Pentaxian it's very much a dream lens 🙂

 

[GMOG]

It's interesting to read all the different views on 40mm lenses in this thread. A while back I bought one of the 40mm Ultrons in Nikon F mount from our sponsor and I took to it like a duck takes to water. Never had a 40mm lens for 35mm format before. I put it on my FM months ago and haven't taken it off yet. Was using it today at a meeting of local ABQ film photographers. I think it's a great focal length.

I shot this one using it, my buddy Bill hunting for VW parts:

 

[CharlesDAMorgan]

It's my most used focal length.

The Voigtlander 40mm f2 Ultron is lovely. As is the 40mm f2.8 Sonnar on my 35S. The former, when used on my Nikon EM, makes for a beautifully compact light camera, the 35S being tiny.

I don't on the whole like fixed lens rangefinder cameras anyway, they tend to be a bit heavy and large, so I'd rather have a camera with interchangeable lens capability for the same weight and size instead.

 

[Armoured]

It's interesting to read all the different views on 40mm lenses in this thread. A while back I bought one of the 40mm Ultrons in Nikon F mount from our sponsor and I took to it like a duck takes to water. Never had a 40mm lens for 35mm format before.

Personally I quite like the 40 focal length as well. I assume a lot of it is just what you're used to, but I've never taken to 35mm length (has that wide feel without the useful extra angle of view). But I learned to shoot on a compact rangefinder with a 40mm lens, much like those discussed above, so just practice.


As for why that was a popular length specifically for the compact rangefinders - I assume as others have mentioned that it was close enough to normal for lens designers, still quite compact even for relatively fast lenses, and the extra depth of field was a bit more forgiving for consumers (and probably focus precision and manufacturing tolerances as well).


I'm kind of bummed that so few digital ILC makers off a really compelling 40. I use 50 equivalents all the time and would really like a slightly-wider, quality, compact and fast one.

 

[David Hughes]

You did note it's a link, didn't you?

Yes, but it is also a question and it prompted what I wrote. I can understand Barnack using off the shelf lenses as I cuts out a lot of work. I think a 40 and a 42mm lens were used on the first 1 or 2 prototypes. I have used both on more modern camera and they work well and give natural view and so I wonder why 50mm, unless it was to give a wider focussed circle. In other words a fudge factor.

But, I cannot see sequences to the range of focal lengths offered and have often wondered why. An opitics designer would surely think in terms of angles and, again, there's no link I can see.

One exception is the 28, 50 and 90mm range I suggested but that took a long, long time to appear. BTW, the reasons for it were suggested to me by someone in the industry but we were discussing Newtonian telescopes at the time; it was a mathematical solution based on customers reactions.


Regards, David

 

[David Hughes]

That it was "off the shelf" is one idea that has been suggested in the past several years. But this is the first indication that Barnack's first lens was a 40mm. I've never seen that 1910 catalog. This is new data for me!

Well over 30 years ago, when I retired, I had the time and money to look into my main interest which was the early aviators and how they got to fly. I was lucky and managed to contact a few families with famous names and speak to the aviators grandsons etc. I also met one or two people who worked with their sons in the 30's. One thing I do remember is how quickly and roughly they made things to test and then refine. I have also seen their diaries, papers and so on and they confirm this.

One set of official Govt. papers said the design was good and worked but they thought their workshop should make the stuff for safety etc... Another person remembered going around town with the inventor looking in shops for something that would do what they wanted.

During the 40's when a lot of items had to be made they had problems with air-sea rescue equipment. I was involved with staff at a very famous firm that made ladies silk underwear at one point because only they and a firm making ecclesiastical garments could produce things in the quantity and quality needed.

I hope this supports the idea that a prototype is made to test ideas and production need different standards and so on.


Regards, David

 

[shawn]

I'm kind of bummed that so few digital ILC makers off a really compelling 40. I use 50 equivalents all the time and would really like a slightly-wider, quality, compact and fast one.

Fuji's 40mm equivalent is a really nice lens. Main complaint against it was just the lack of an aperture ring, and Fuji just addressed that in the new version.

On my A7RII I use the Canon EF 40mm f/2.8 STM with the Sigma AF adapter. A little bigger than if it were a native lens but not terrible and it works very well on the Sony.

Shawn

 

[Armoured]

Fuji's 40mm equivalent is a really nice lens. Main complaint against it was just the lack of an aperture ring, and Fuji just addressed that in the new version.

Thanks for that info, but I'm going to have to forget that immediately to avoid the temptation of any new systems.

But I should have said 'few' ILC digital offerings.

Although even there, I'm a tiny bit disappointed - if you mean the Fuji 27 - it's only at f2.8. It's very nice it's a small lens indeed but then the compact rangefinders were often f1.7 to f2.

I'm sure it's a great lens but not sure it gets to compelling. That said, I really should try it.

 

[shawn]

Although even there, I'm a tiny bit disappointed - if you mean the Fuji 27 - it's only at f2.8. It's very nice it's a small lens indeed but then the compact rangefinders were often f1.7 to f2.


I'm sure it's a great lens but not sure it gets to compelling. That said, I really should try it.

Tradeoff between size and speed. It being so tiny is very nice.

The old rangefinders at f1.7 or f2 were dealing with 400 speed film, the Fuji bodies have no problem going well above that. That lens on an XE2 (or later) is a great little setup.

https://www.flickr.com/groups/2241404@N20/pool/with/51132100442/

Shawn

 

[Godfrey]

"Normal" is, by convention, a focal length approximately equal to the diagonal of the capture format. This produces a look and feel in images that closely approximates the field of view of the human eye, that's why the term 'normal' is used to describe it.

This is one of the reasons I've heard as to why 40mm lens was chosen for a lot of compact cameras, along with reasons like "it's easy to design a symmetrical 40mm lens that is both compact and fast" and "it's inexpensive to make a fast 40mm lens that fits with the pricing of this class of camera."

I know Rollei used a 40mm lens in the classic Rollei 35 design because it was both compact and inexpensive (according to Klaus Prochnow), and allowed them to use a very high quality lens in that tiny camera.

I don't really care too much about frame line accuracy or whatever ... No separate tunnel optical viewfinder is all that precise anyway, being dependent upon eye position and each individual's eyesight, never mind placement in the camera (how far off the optical axis of the taking lens, etc). It's all an approximation. I use frame lines as a guide, not an absolute.

My Rollei 35S has a nice fast Sonnar 40mm f/2.8 lens and is delightfully compact. My Minox 35GT-D has a nice fast 35mm f/2.8 lens and is similarly delightfully compact. I have the excellent Pentax SMC-L 43mm f/1.9 Special which I've used on the M4-2, M9, M-P typ240, M-D typ262, and use today on the CL (digital). It's fine lens and nets beautiful photographs on anything I use it on.

My take is that I pick up whatever camera and lens comes along and learn how to make good photographs with it, presuming that it achieves the quality I'm looking for. I learn to understand whatever the particular camera/lens sees and try to take the most advantage of it. Whether I want slightly wide, slightly tele, or so-called normal ... I use what I've got to hand, and work with whatever it's got. 🙂

G

 

[das]

To me, a close-focusing (like at least down to 0.3m) 35mm FL SLR lens is perhaps the most versatile lens in 35mm photography. RF lenses can typically only do 0.7m on a film camera, which is really not close enough. A 35/40 can substitute for a 50 by physically moving closer to the subject, but a 50 cannot substitute for a 35 (like you cannot walk far enough away from the subject to get it all in). Also, during the late 1970s, compactness was all the rage. The relatively low-cost "pancake" 40s developed by Nikon, Konica, Contax, etc. from the 70s to the 90s suited those smaller SLRs well and were more versatile than the 50s.

 

[agentlossing]

It's a matter of what you're used to and have adapted to working with. I personally love 40mm and find it extremely good for the streets, it's like a 50mm with lots of added ease of framing, you don't have to get as far back from people in order to get some context. But I use 35mm a lot now, I can see how, if you've adapted to working with it, 40mm might seem tight. Treat a 40 like a 50 and it'll really click, it doesn't suck in as much peripheral detail as 35.

 

[Paul T.]

I suspect a key reason was that the standard lens is 50mm.... but a 40mm demands less precision in focusing, while being not as expensive to produce as a 35mm.

That is surely one of the reasons you see them so often on cameras with short-ish rangefinder bases.

Personally I love the 40mm field of view.

 

[Armoured]

Tradeoff between size and speed. It being so tiny is very nice.

The old rangefinders at f1.7 or f2 were dealing with 400 speed film, the Fuji bodies have no problem going well above that. That lens on an XE2 (or later) is a great little setup.

You're right, it's a personal opinion only that I don't find that particular combination compelling in a 40mm; just a preference.

Perhaps a better take on my part would be to say that I'm disappointed there aren't more options in the 40mm equivalent length.

I have the M-mount Minolta 40mmf2 and quite like it. It's tiny. Personally I wouldn't really want or need f1.4 or equivalent in a 40 for the size trade-off; but ~f2 with good autofocus would be very attractive. (I should note I'm in a climate with poor light much of the year and even with digital, that extra stop from 2.8 to 2 can make a difference. YMMV).

Again, I'm sure there are some exceptions, just not that many.

As a different take on this: plenty of 50/1.8 or thereabouts on offer, cheap; a 40/2 that's small-ish would be something I'd jump on.