Derive 75mm from 50mm

[BJohn]

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I need help regarding the following:

 

- I currently own the Summilux-M 50 and I shoot portraits at minimum focus distance.

- Sometimes, I am not close enough for what I have in mind.

 

Now I had the idea to buy the current Summicron-M 75.

 

I am not a huge fan of cropping too much in the post, but...and this struggles me a lot:

 

(Assuming I would shoot in the same distance to the subject and with F2.0.)

 

The effect of the bokeh, the depth of field, the perspective, nearly anything, would be the same if I either crop 66.67% or shoot with the 75mm, right?

 

I mean, even the colouring and contrast behaviour should be similar, as the Summicron 75 was derived from the Summilux 50.

 

So my money would be better invested in an APO50 or something completely different than a Summicron 75?

 

I also decided not to buy the APO 90, because the reproduction ratio is even lower than the 50mm.

 

Cheers, Ben!

Edited August 20, 2018 by BJohn

[Gregm61]

The 75mm f2 APO-Summicron can be a challenging lens to use. I have one. Sent it to DAG at one point as I was having so many problems focusing it accurately. He checked it out and told me it was within factory tolerances. The focus throw is so short it can be a very easy lens to "miss" the focus the tiniest amount, but enough to matter.

 

A couple of things I have done since, first, I picked up a new 75mm f2.4 Summarit, which is just a pleasure to use. Easy to achieve consistently accurate focus at all apertures and distances, right down to the closest .7 meters.

 

Second, I have worked on my own focus method with the rangefinder and now do a better job of keeping my eye centered to maximize the contrast of the patch and also utilize both the matching of the lines and watching for the contrast effect you can see when the image jumps into and out of focus, which has allowed me to better focus my 75mm f2 as well as now being able to consistently and accurately focus the 135mm f3.4 APO-Telyt without the use of contrast reducing magnifiers.

 

The crop from 50 to 75mm just isn't all that much to be honest. If I owned the 50mm f1.4 I don't think I'd bother with a 75mm lens.

Edited August 20, 2018 by Gregm61

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[01af]

I currently own the Summilux-M 50 and I shoot portraits at minimum focus distance. Sometimes, I am not close enough for what I have in mind. Now I had the idea to buy the current Apo-Summicron-M 75 Asph. [...] Assuming I would shoot from the same distance to the subject and with f/2. The effect of the bokeh, the depth of field, the perspective, nearly anything, would be the same if I either crop 67 % or shoot with the 75 mm, right?

Wrong.

 

Perspective would remain the same (as this depends solely on your position you're shooting from, i. e. the distance basically) but everything else would change ... albeit not by much. Anyway, to rely on cropping on a regular basis for your intended work is a bad idea. You should crop only when you had to snap your shot quickly and hadn't the time for a better composition. So, for tight framing in portrait work, better get a 75 mm or 90 mm lens.

 

You might also want to check out close-up lenses to add to your 50 mm lens (+1.5, +1.65, or +2 dpt)—but then, you'd have to resort to using an EVF because the rangefinder won't work in conjunction with close-up lenses, and the very short shooting distance would lead to quirky pictures.

 

 

So my money would be better invested in an Apo-Summicron-M 50 Asph or something completely different than an Apo-Summicron 75?

When you're unhappy with what a 50 mm lens can do for you then it wouldn't make sense to buy another 50 mm lens, would it?

 

 

I also decided not to buy the Apo-Summicron-M 90 Asph because the reproduction ratio is even lower than the 50 mm.

 

As a matter of fact, a 90 mm lens at 1 m, such as the Apo-Summicron, has a higher magnification (1:9) than a 50 mm lens at 0.7 m (1:11.3). The highest magnification of all regular M lenses (except the Macro-Elmar-M 90 mm) is 1:7 which is found in the Apo-Summicron-M 75 Asph and the Summarit-M 75/2.4.

 

 

[epand56]

Maybe this sounds like an heresy, but I owe a CV Heliar 75/2.5 and I'm extremely happy with it. It's a very cheap (not easy to find, though) but extremely sharp lens, that renders very well and with a nice bokeh. It's also small and very well built. I would suggest you a try.

[BJohn]

As a matter of fact, a 90 mm lens at 1 m, such as the Apo-Summicron, has a higher magnification (1:9) than a 50 mm lens at 0.7 m (1:11.3). The highest magnification of all regular M lenses (except the Macro-Elmar-M 90 mm) is 1:7 which is found in the Apo-Summicron-M 75 Asph and the Summarit-M 75/2.4.

 

Oh, I made a big mistake there...I wrote down the magnification ratios on a piece of paper down and mixed them up. So maybe 90mm would be an option, although I believe it is hard to focus using the rangefinder mechanism?

 

Thank you all very much for your responses, really appreciate them! They help a lot!

[cp995]

Maybe this sounds like an heresy, but I owe a CV Heliar 75/2.5 and I'm extremely happy with it. It's a very cheap (not easy to find, though) but extremely sharp lens, that renders very well and with a nice bokeh. It's also small and very well built. I would suggest you a try.

 

Why "herasy"?

The CV Heliar 75/2.5 is unique in every perspective.

I would never buy any Leica Summicron/Summarit 75 to replace it.

 

Unfortunately hard to get and I don't understand why CV replaced it with this worse Heliar 1.8/75 VM ...

[ckuwajima]

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Oh, I made a big mistake there...I wrote down the magnification ratios on a piece of paper down and mixed them up. So maybe 90mm would be an option, although I believe it is hard to focus using the rangefinder mechanism?

 

Thank you all very much for your responses, really appreciate them! They help a lot!

 

I do not own a Summicron 75, but I have a Summilux 75 which I find more difficult to focus wide open with rangefinder than my APO Summicron 90mm.

[otto.f]

John, you mean you have the Summilux 50 asph, or the pre-asph? If it’s the asph and if that’s your only lens I would ask myself if I’d want a lens that’s so close in angle as a 75. If you do, I’d really think of the VC Color Heliar 75/2.5 too, because that’s a lens with a real different character as the 50 Summilux asph.

Edited August 20, 2018 by otto.f

[BJohn]

John, you mean you have the Summilux 50 asph, or the pre-asph? If it’s the asph and if that’s your only lens I would ask myself if I’d want a lens that’s so close in angle as a 75. If you do, I’d really think of the VC Color Heliar 75/2.5 too, because that’s a lens with a real different character as the 50 Summilux asph.

 

I currently own a 21, 28 and 50mm. It is the most recent ASPH. version. Currently I am in between an APO90 and the VC Color Heliar 75/2.5. The example images I found look terrific. But, are there any copies with rangefinder coupling?

[a.noctilux]

I currently own a 21, 28 and 50mm. It is the most recent ASPH. version. Currently I am in between an APO90 and the VC Color Heliar 75/2.5. The example images I found look terrific. But, are there any copies with rangefinder coupling?

 

Color Heliar 75mm f/2.5 is rangefinder coupling.

 

For more infos, if not already done,

 

have a look at this old thread: https://www.l-camera-forum.com/topic/230837-voigtlander-color-heliar-75mm-f25-lens/

even if some pictures don't appear anymore...

[otto.f]

I had not often problems with focusing my APO 90 on my M9, but on the M10 it’s practically 100% bull’s eye. In the range 21, 28, 50 the next one would logically be a 90. I’d say.

Edited August 20, 2018 by otto.f

[IkarusJohn]

I currently own a 21, 28 and 50mm. It is the most recent ASPH. version. Currently I am in between an APO90 and the VC Color Heliar 75/2.5. The example images I found look terrific. But, are there any copies with rangefinder coupling?

I have the same range of M lenses. I had the AA 75 Summicron and also struggled with accurate focus and sold it. I had the AA 90 Summicron, and didn’t gel with that either - too tight and the same difficulties with focus accuracy.

 

Bought the 75 Summilux, and am very happy. Longer focus throw made accurate focus easier to achieve, and the lens has a different character to the 50 Summilux ASPH. The field of view is close, but the character quite different - wide open, the 75 Summilux is a little soft (nice for portraits) and stopped down, tack sharp.

[ktmrider2]

Don't own a 75 but do own both 50 and 90.  I have had a 90 since I have owned a Leica (at least since 1975) and have never had problems using the rangefinder for focusing.  Remember, it is only since the M240 that "live view" or an EVF has been an option.  And the 90 is one of the three classic focal lengths (35,50,90) for Leica M photography.  The 90 focuses just fine with the .72 magnification found on the M2 and most subsequent film Leica's.

 

I admit that super fast lenses can be challenging to focus, especially in low light when used wide open.  Well, my 90's have been f2.8, are reasonably priced for Leitz lenses, and wonderful for portraits.  The 90 is one half of my travel kit with the other being a 35mm.  I have always thought the 75 was too close to either the 50 or 90 and wanting to keep my M kit fairly light, I never felt the need to own one.  

 

I don't have any experience with any 75mm lenses but have heard good things about both 75's made by Voightlander.  Apparently, the 75f1.8 is soft wide open (perfect for portraits) but sharpens up very well by f4-5.6.  And most people I know who have the 75f2.5 won't part with it.  Both are available from Cameraquest for $699 (75f1.8) or $599 (75f2.5).  The 75f2.5 is in LTM mount and needs the appropriate adopter.

Edited August 21, 2018 by ktmrider2

[adan]

As I recall from discussions in the M8 days, to compare effective aperture from the point of view of DoF - not exposure - you have to multiply the real aperture of the lens you are cropping by the same factor as the crop.

 

E.G. a 50mm f/1.4 cropped to effective 75mm (e.g. on a TL or CL, or in Photoshop) would give the DoF of a 75mm f/2.1 lens (1.4 x 1.5 = 2.1). So not quite the same. And that will also affect the size of the blur circles (the "size" of the bokeh, but not perhaps the character).

_________________________

 

"Derived from" does not mean "mostly the same as." The 75 APO has one less element than the 50 ASPH, which can mean more contrast (fewer surfaces to cause flare).

 

I used a 50 ASPH f/1.4 on the M8 - only a 1.333 crop, not 1.5 - and it was already quite a bit less sharp than a 75 ASMA on an uncropped sensor. Exactly as the weaker MTF charts would predict. And slightly less contrast (in a good way - not quite as stark as the 75 Summicron). On the whole, the 50 Summilux "cropped" looks more like the original 75 Summilux, with a bit more contrast and pinker color, rather than the 75 Summicron. In my evaluation.

[lct]

50/1.4 asph on APS-C (digital CL) looks sharper than 75/1.4 on FF (M240) in my view, especially at f/1.4 and f/2. Reason why i don't use my 50/1.4 asph for portraits with the CL but a 50/1.4 pre-asph or a ZM 50/1.5 preferably. If i were in the OP's shoes i would use a 75/2 apo the speed and IQ of which are closer to the 50/1.4 asph than my otherwise favorite 75/2.5 IMHO.

Edited August 21, 2018 by lct

[250swb]

The CV 75mm f2.5 Heliar is the way to go, not just because it saves a lot of angst questioning the cost of a Leica equivalent, but because it actually is a genuine equivalent lens to the Summarit. Compare the Heliar with the Summicron however and you save a lot of weight, but lose half a stop, image quality is again at like for like apertures truly competitive. You'll be hard pressed to notice the difference in bokeh, either quality or depth, between f2 and f2.5.

Edited August 21, 2018 by 250swb

[otto.f]

The CV 75mm f2.5 Heliar is the way to go, not just because it saves a lot of angst questioning the cost of a Leica equivalent, but because it actually is a genuine equivalent lens to the Summarit. Compare the Heliar with the Summicron however and you save a lot of weight, but lose half a stop, image quality is again at like for like apertures truly competitive. You'll be hard pressed to notice the difference in bokeh, either quality or depth, between f2 and f2.5.

I agree but it’s strange that I read a lot of forum members the other day being extremely enthusiastic about the Summarit 75/2.4 or even 2.5 and this lens is now behind the scenes in this thread?

[01af]

The Voigtländer Heliar 75 mm 1:2.5 sure is a good lens but the minimum focusing distance is 1 m—I'd guess this won't suit BJohn's requirements well.

 

The Summarit-M 75 mm 1:2.5 has a minimum focusing distance of 0.9 m; the Summarit-M 75 mm 1:2.4, 0.7 m. That's why I'd recommend the latter. Despite the difference in the nominal speeds, the two Summarit-M 75 mm versions are the same lens, except their different minimum focusing distances. At normal portrait distance (1.5 - 3 m) they are sharper than the Apo-summicron-M 75 mm Asph at the frame's center ... only the fall-off towards the frame's edges is slighty worse (irrelevant for portraiture). They have less inclination to flare than the Apo-Summicron and are easier to focus. More affordable, too.

[250swb]

I agree but it’s strange that I read a lot of forum members the other day being extremely enthusiastic about the Summarit 75/2.4 or even 2.5 and this lens is now behind the scenes in this thread?

 

Some people prefer to believe the fatness of their wallet rather than the fact that a great 75mm lens is relatively easy to design and manufacture if you put resources into it, just like any 50mm lens. And within the CV range there are 'gems' that they put a lot into, and strangely enough these 'gems' are now the ones that are hard to get, perhaps because they cost more to make than they charged for them?

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[BJohn]

I visited Leica Wetzlar yesterday, so I tried out a 90mm and a 75mm. Mostly to see how I get used to the framelines and the whole handling of longer lenses.

 

I have to admit, that 75 is too close to my 50mm. As I don't want to sell my 50mm, I will definitely skip the 75.

 

I found it quite easy to get everything in focus with my M10 and the store copy of the APO90. What really impressed me was the creamy bokeh and the sharpness.

 

But what felt weird was the very small frame to compose with. I mean, I only had spent about 15 minutes with the lens...so I believe you need some time to get used to it.

 

So thank you all for your replies, really helped me a lot.