35mm lens with R3A 40mm frame lines

[Huck Finn]

When considering the question of whether you can use a 35/1.7 Ultron, for example, on the R3A, consider whether the lens in question is actually the advertised focal length. In the case of the Ultron, it is not. The good news is that it is actually 37mm, suggesting that it can be used on a camera with 40mm frame lines with confidence. The CV 35/2.5 Pancake I is an even better match for the R3A; its actual focal length is 38mm.

Let's reverse the question. Can you use a 40mm lens, the Rollei 40/2.8 Sonnar for example, on a camera with 35mm frame lines? In this case, probably not since the Sonnar is close to 42mm in actual focal length.

When Popular Photograqphy tests lenses, they measure the actual focal lengths & maximum apertures. It's interesting to look at this information when considering whether to use a lens with frame lines that are different than those that match the lens. I looked at 5 prime Leica lenses for their actual measurements & found that in all 5 cases the maximum aperture was within 0.1mm of what was advertised and that in 4 of 5 cases the focal length was within 1mm of what was advertised. In contrast, none of the 6 CV primes matched their stated maximum apertures within 0.1mm & 5 of 6 were different than their advertised focal length by 1mm or more.

There is certainly a trend in this comparison between CV & Leica. What is not known from this comparison is whether CV lenses are consistently different from what their label indicates or if these differences are due to sample variations.

Here is a list of the Pop Photo measurements that I have seen for LTM & M-mount lenses:

CV 12/5.6 (12.38/6.14)
CV 35/2.5 P-I (38.04/2.68)
CV 35/1.7 (37/1.8)
CV 50/1.5 (52.92/1.62)
CV 50/3.5 (51.72/3.65)
CV 75/2.5 (76.82/2.68)

Leica 28/2 ASPH (28.41/2.07)
Leica 50/1.4 ASPH (50.71/1.49)
Leica 50/2 (50.38/1.94)
Leica 50/2.8 (50.46/2.82)
Leica 90/4 (90.5/4.03) Macro

Rollei 40/2.8 (41.68/2.96)
Rollei 80/2.8 (79.7/2.8)

 

[unsharp]

Very interesting

Very interesting

Thanks for sharing these focal lenght test results Huck. I am just shooting a test roll to see, among other things, how well my Summicron 35 asph matches the 40mm frames on my R3A. Actually, I allready did, but failed to put in the film correct, resulting in a blank roll. How extremely embarrasing in the photo shop: look for the little red dot on the winder to move! - I know, I know, just get me another roll, pls 😱 😱

Then comes another question: How much "40mm" are the frames? I will test at 3 ranges: 1.5, 3.0, 10m and see how they match in the top left corner, holding the camera "horizontal". As I understand this will change with distance? I picked 1.5 and 3m because i think thats the distance where you will cut of peoples feet unless knowing what the lens will get 🙂

BTW: Does this paper have any info on the Nokton 40mm f1,4 focal lenght?

Anders

 

[Huck Finn]

Anders, unfortunately Pop Photo has not reviewed the 40 Nokton, which is the one I also most wanted to know about. I think that there has been a lot of interest in this lens because of its compact size & equally compact 😉 price, but not everyone has an old CL or CLE hanging around or wants to buy an R3A or Rollei 35 RF just for the sake of 40 mm frame lines. They would just like to use it on the camera that they already have with 35 or 50 mm frame lines.

It would be nice to know if it leans more to the long side or the wide side of 40 mm. My hunch is that it's probably on the long side because I've read that the 40 frame lines for the R3A only give 85% coverage - which is your point - unlike other CV frame lines, which cover 87%. A 40 Nokton which is more like the 42 mm length of the Rollei Sonnar would be a better match for these slightly narrower frame lines.

I'll look forward to the results of your test.

Huck

 

[rover]

Herb Keppler mentioned in his article about the R3a that Pop will do a full test on the 40 Nokton.

 

[Huck Finn]

I'll look forward to that, Rover. did he give any indication what month that might be?

I stopped at the library & obtained a few more Pop Photo lens measurements:

CV 15/4.5 (NA/4.12)
CV 25/4 (24.84/3.82)

Leica 21/2.8 ASPH (20.49/2.68)
Leica 35/1.4 (36.48/1.58)
Leica 35/1.4 ASPH (34.44/1.38)
Leica 50/1.4 (53.02/1.5)
Leica 75/1.4 (77.5/1.62)
Leica 90/2 AA (88.14/1.99)

It's interesting to note that this list includes some of the older Summiluxes & that they are not as spot on as my original list or as the newer Leica lenses on this list. The CV lenses continue to vary from their published spec's. In the case of the 15/4.5, the variance in maximum aperture is the largest I have seen, and in this case it is in a positive direction - meaning that the lens is faster than reported. They legitimately could have called this lens a 15/4.

 

[Huck Finn]

I'm realizing that this has implications for the R-D1. Because effective focal lengths are 50% greater than for 135 format, any discrepancies in measured focal length are increased by 50%. Given that the 28/35/50 frame lines result in 42/52.5/75 coverage, which lenses aboe come closest to actuall matching that?

Leica 28/2 ASPH = 42 on R-D1
Leica 35/1.4 ASPH = 51.7 on R-D1
Leica 50/2 = 75.59 on R-D1

Of course, there may be a preference for variations, especially on the longest lenses to get closer to true portrait length. In this case the Leica 50/1.4 pre-ASPH becomes 79.5 on the R-D1 & the CV 50/1.5 becomes 79.4.

At the standard focal length, the lens most at variance is the CV 35/2.5, which becomes 57 on the R-D1, while the CV 35/1.7 becomes 55.8. here the question becomes one of whether you want to get as close to 50 as possible or whether you want lenses that are closer to 60.

So, in selecting lenses for the R-D1, it may be worth considering actual focal length along with other factors, so you are really getting the perspective you want.

 

[Doug]

Isn't the RD-1 "crop factor" 1.53x? That would bring it to

Leica 28/2 ASPH = 43.47 on R-D1
Leica 35/1.4 ASPH = 52.69 on R-D1
Leica 50/2 = 77.08 on R-D1

 

[Roger Hicks]

Many 50mm lenses were always a bit long. Indeed it's disputable whether they are really 50mm or 2 inch (50.8mm): remember that the Leica was introduced by a microscope manufacturer and that RMS (Royal Microscopic(al?) Society) threads and dimensions are the oldest thread standards in the world -- which is also why Leica screw is 26 tpi not 1mm. I seem tp recall -- and I may be wrong -- that Elmars were around 51.6 mm.

It also seems quite likely that the 42.5mm and 40mm Biogon were the same lens.


Cheers,

Roger

 

[Huck Finn]

Isn't the RD-1 "crop factor" 1.53x? That would bring it to

Leica 28/2 ASPH = 43.47 on R-D1
Leica 35/1.4 ASPH = 52.69 on R-D1
Leica 50/2 = 77.08 on R-D1

Thanks for making it even more precise, Doug. 🙂

 

[Huck Finn]

Many 50mm lenses were always a bit long. Indeed it's disputable whether they are really 50mm or 2 inch (50.8mm): remember that the Leica was introduced by a microscope manufacturer and that RMS (Royal Microscopic(al?) Society) threads and dimensions are the oldest thread standards in the world -- which is also why Leica screw is 26 tpi not 1mm. I seem tp recall -- and I may be wrong -- that Elmars were around 51.6 mm.

It also seems quite likely that the 42.5mm and 40mm Biogon were the same lens.


Cheers,

Roger

Yes, Roger, I believe you're right.

I think that for today's users the greatest significance for 50's & 28's is for R-D1 users.

Otherwise, the most significant variances are for 35 & 40 lenses and for moderate telephotos (75 - 90) so users can no which lenses can be readily used with different frame lines.

Purchaers of the new ZI, for example, might be pleased to know that the Leica 90/2 AA is only 88 mm & therefore should work easily with the ZI's 85 mm frame lines. This is potentially a big savings over the pricey 85/2 Sonnar if you can find one of the Leicas used.

 

[Doug]

Hi Huck-- I hope we're not assuming viewfinder framelines are exactly matching the marked focal lengths? Or that there is a uniform coverage proportion of it like 85%? I suspect there's more variation among viewfinders than the lenses, so any matching of fields of view becomes complex.

It would be nice to have more consistency, but with multiple manufacturers, and little in the way of standards, AND field-size changes at different focal distances, and parallax issues... Is there much use to sweating small variations in focal length...

The relationships are probably less casual with a proprietary system like the Contax G and with fixed-lens RFs with good frame control like the Fuji GS645.

 

[aizan]

precision schmidgion! rangefinders aren't for precise framing of edges. 😛

 

[Huck Finn]

Well, guys, to each his own. You can't be too casual about this stuff or you'll lop off someone's head - maybe not a bad idea depending on whose head it is. 😱

You can certainly take greater ease shooting a 35 mm lens with narrower 40 mm frame lines, knowing that you'll get at least what you can see & probably more, than you can the other way around, knowing that the lens will give you less than what you see in the frame lines but not knowing just what it's going to cut out. This becomes exaccerbated with a lens like the Rollei 40 Sonnar which at 42 mm is even narrower still. OTOH, you've got a decent shot with a narrower lens on wider frame lines with a lens like the Leica 90 Summicron AA since it is only 88 & the ZI frame lines are 85.

Anyway here's my last word on the subject:

Hexanon KM 28/2.8 (28.92/2.93)
Hexanon KM 50/2 (53.34/2.12)
Hexanon KM 90/2.8 (92.43/2.93)

The Leica 28/2 ASPH remains a better choice for the R-D1 if you want to stay as wide as possible. The KM 50/2 is the longest of the 50's I have looked at & may be the best candidate for a true portrait lens on the R-D1 at a length of 81.3 mm with the 1.53 crop factor. The KM would not be a good fit for the ZI 85 mm frame lines.

Amen 😛

 

[unsharp]

R3A, 40mm frames and Summicron 35mm test

R3A, 40mm frames and Summicron 35mm test

Here are four test pictures of a Summicron 35mm ASPH on a R3A and 40mm frames. I shot them today at four distances: 1.5, 3, 10 and 25 meters.

I used the top left corner of the 40mm frames and marked the frames in the scans. Sorry if the text came out a bit small, I should have resized the images first, and THEN entered the text 😱 .

As you can see the R3As 40mm frames don't match the 35mm Summicron's angle of view very well, and the error seams to increase a little bit with distance.

To me this is a bit too much, but then again this just fuels my search for a M4! 😀

Anders

 

[Huck Finn]

Anders, you can probably learn to compensate with tight framing, but when I look at these pictures in reverse, I think how much you'd be cutting out of your picture if you shoot with a 40 mm lens, using 35 mm frame lines. Not good.

Thanks so much for sharing the results. Very interesting. 🙂

 

[Doug]

Huck, sorry if I seemed to suggest it wasn't worth discussing! Just that we should probably find some (or do some) tests of viewfinders too. 🙂 And then, knowing about what we'll get compared to what we see, well, at least we're better informed! And expect discrepancies.

And those RD-1 folk have an unnatural advantage! Interesting stuff, Anders. 🙂 I'd agree there's a lot of extra area captured outside the frames, and maybe hard to adjust to that much.

 

[Huck Finn]

Huck, sorry if I seemed to suggest it wasn't worth discussing! Just that we should probably find some (or do some) tests of viewfinders too. 🙂 And then, knowing about what we'll get compared to what we see, well, at least we're better informed! And expect discrepancies.

Doug, please no apologies. I greatly appreciated your comments & thought that you made excellent points - as you always do. I'm the one who thought I was beating a dead horse. I was just trying to have some laughs by saying "Amen 😛."
It was nothing to be taken seriously.

Anyway you're right about testing the frame lines & I too have read that there is variability among them. Actually I should probably start by comparing the frame lines on my own 2 RFs.

Cheers . . .

 

[hoppinghippos]

unsharp: thanks very much for posting your results, they're are indeed very interesting. I had hopes that I could somehow get a 28mm lens and use it with my R3A but looking at your results I reallly doubt so now! unless I somehow doubled the 50mm framelines mentally!

 

[aizan]

physical memory can be quite accurate. anyhow, if that doesn't work, there's always "the best 28mm viewfinder ever".

 

[Huck Finn]

unsharp: thanks very much for posting your results, they're are indeed very interesting. I had hopes that I could somehow get a 28mm lens and use it with my R3A but looking at your results I reallly doubt so now! unless I somehow doubled the 50mm framelines mentally!

Darrel, I've been experimenting with the CV 28/3.5 without an auxiliary finder on my Rollei 35RF - 40 mm frame lines like your R3A. I use it for people when I want to include their outdoor environment. I frame with the 40 mm frame lines to get the people situated where I want them in the picture & I don't care about how precise I am in just how much of their environment isw included. I'm also thinking that I can get in closer without cutting out what's around them. My first roll isn't developed yet, so I'll let you know how it goes.