Leica APO-Telyt-M 135mm f/3.4 vs Leica 50mm f/1.4 Summilux-M ASPH - Focal Length vs Aperture
One of these days, I really should get some contact lenses - or at the very least - wear corrective eyewear when I'm not driving. But for someone like me, I kind of like the way world always looks a little blurry around me. Not seeing in 20/20 allows me to focus my attention on the task at hand, instead of falling victim to distractions. The only problem is, my shortsightedness does affects my ability to focus accurately on a rangefinder.
For the most part, not having perfect vision with a Leica M10 hasn't been too much of a burden to me. As long as I stick between the 21 to 50mm focal length and shoot closer up, I'm not materially impacted by my less than perfect vision. And should I decide to venture off to 75mm and 90mm, I can usually guarantee focus by stopping down. But then, what am I to do if I decide to venture off the beaten path further to 135mm? Would I still be able to reasonably acquire focus?
Mind you, why would I want to do something as taxing as veering off the edge of comfort? It's not like 135mm is a common focal length with rangefinders. Having said that, 135mm does have its moments. In the lexicon of what-you-see-is-what-you-get photography, typical of through-the-lens and electronic framing, the 135mm focal length is generally considered the gold standard for taking portraitures and fashion photography.
With that in mind, I decided to take a look at the 135mm focal length on a rangefinder, just to see what the fuss in focusing is all about. Seemed like a good plan... only... I didn't have an example of a 135mm M-mount lens. But wouldn't you know it, I found a copy of the Leica APO-Telyt-M 135mm f/3.4 at the Leica Store Soho, in New York City. I mean, what are the odds. It's not as if this lens is exactly a favorite with Leica enthusiast, despite high praises.
Apparently, this is an exceptional lens. According to the Leica Pocket Book, 8th edition, the APO-Telyt 135mm "belongs arguably to the two or three best Leica M-lenses ever made" (as of writing, at July 2012). However, it also stated that this lens is "of limited use, [since] the viewfinder frame and the accuracy [of the focusing] are claimed to be pushed to physical limits" in normal use. In other words, this lens is a handful to use.
It is. At 135mm, the law of reciprocity requires I shoot at a shutter speed twice the focal length of the lens, in order to mitigate camera shake. Rounding it down, that means the minimum shutter speed is 1/250s. It's not as if the Leica M10 has image stabilization. Admittedly, I could always offset higher shutter speeds by shooting wider open. But with a maximum aperture of f/3.4, the 135 APO-Telyt is already close to three stops less in flexibility.
Admittedly, none of the aforementioned demands are insurmountable. It's just a matter of taking the effort to prepare for optimal light, given the need to shoot at higher shutter speeds and lower aperture. But then, there is still that pesky matter of the 135mm focal length framed on the typical 0.72x magnification viewfinder standard on most Leica rangefinders, as mentioned on the Leica Pocket Book, 8th edition. Let me elaborate.
At 135mm, the frame line is not much bigger than the focusing window at 0.72x magnification. If I had to make an estimate, I'd say the 135mm frame line amounts to no more than 3% the area of the viewfinder. As for the focusing experience at 0.72x magnification, the APO-Telyt 135mm can offer accuracy at closer shooting distance. But as distance between the lens and subject grows further, distinguishable details necessary in determining focus inside the focusing window diminishes.
Of course, an easy fix to pad uncertainty in focusing is to stop down. Unfortunately, the depth of field of this 135mm lens is relatively shallow, even at lower aperture. Normally, that shouldn't be an issue, given the likelihood of fine tuning focus. But since, the focusing throw isn't long enough to sufficiently permit fine tuning, and because the focusing window offers an inexact focusing experience, hitting tack focus is anything but certain at 0.72x magnification.
So if the APO-Telyt-M 135mm f/3.4 isn't especially stellar as a telephoto lens in capturing far away subjects with accuracy, what is the point of getting it at all? Well, as I've already pointed out, the 135mm focal length is the gold standard of portraiture and fashion photography. But is it really? To determine whether the 135mm focal length really offers a competitive advantage, I decided to compare it with the Leica 50mm f/1.4 Summilux-M ASPH.
In conducting this comparison, I decided to shoot the APO-Telyt 135 at f/4, since I wanted a little padding in depth of field. As for the 50mm Summilux, I decided to shoot it wide open on every image capture. The objective of this comparison is to determine whether the APO-Telyt 135 offers an appreciable advantage to the 50mm Summilux in rendering. Also worth noting, the APO-Telyt 135 was shot on live view, in order to improve the probability of hitting focus.
Of course, I couldn't have conducted this comparison during the evening, when the APO-Telyt 135 would have been at a three stop disadvantage. Instead, I did this comparison in daylight. Because of that, I fitted on the 50mm Summilux a 3 stop Neutral Density Filter. That way, I was able to use the same ISO setting and similar shutter speeds for every shot - that was - until I started to stop down further on the APO-Telyt 135.
At f/4, the APO-Telyt 135 wasn't much better in forgiveness than at maximum aperture. But then, I quickly made a discovery. When stopped down, the 135mm focal length was still comparable to the 50 Summilux wide open in isolating the subject and diffusing background details - up to f/8 to f/11 (depending on the shooting distance). But since there wasn't any benefit in the focusing experience when stopped down, I should have just continued to shoot wider open.
The APO-Telyt 135 may possibly be the most cumbersome M-mount lens I've ever used. It makes one wonder whether all the trouble is worth it - considering that the 50mm Summilux when shot wide open can document in more or less the same way. But, the devil is in the details. To be frank, there is something very distinct in the rendering of the APO-Telyt 135. When this lens gets it right, it gets it more right than the 50mm Summilux.
Admittedly, the 50mm Summilux, when shot wide open at closer distance does appear to render bokeh in a more visually appealing way. That said, bokeh isn't the standard in evaluating a photo. In my opinion, the APO-Telyt 135 appears to be a more well-rounded lens. It resolve detail with more perceived definition, it renders color more accurately, and it has even more micro contrast depth in creating a greater impression of volume.
To be fair, the 50mm Summilux did have a Neutral Density Filter on, which could account for some color cast. So I goofed 😖But speaking anecdotally, the color balance of the 50 Summilux with the B+W Neutral Density filter is very close to the color rendering without the filter. Frankly, I’ve never seen an M-mount lens render color as accurately as the APO-Telyt 135.
In conclusion, I must concur with the Leica Pocket Book, 8th edition. The APO-Telyt-M 135mm f/3.4 is truly a remarkable lens. In that way, this lens is worth considering. That said, the APO-Telyt 135 is just too much a prima donna for daily use. Because of that, whatever added benefit it offers is only worth the trouble for professional use - especially since much of what it can do can be done with a fast normal lens shot at maximum aperture.
If only it wasn't such a handful. I mean, this lens tired me out so much, that after an hour, I gave up on shooting anymore portraitures. That said, I really didn't help my cause by not wearing any corrective eyewear. But then again, I was shooting in live view. So in the end, my shortsightedness made no difference at all.
Some images have been tweaked in Adobe Lightroom. None of the images have been cropped.
Attached below is an illustration of the 135mm frame lines at 0.72x magnification. The Leica M10 has 0.73x magnification.