Leica M10 vs Leica SL - Part II - High ISO and Dynamic Range

Anna was particularly relieved that I didn't conduct the high ISO and dynamic range test, while in New York. The pictures taken for this comparison between the Leica M10 and Leica SL, for a lack of a better way of saying it, was downright awful. But wasn't that suppose to be the point? In examining the extent of high ISO and dynamic range, one has to deliberately ruin each shot, for the purpose of fixing it in post. Only thing is, I wish I ruined it with greater precision.

Always the obsessive compulsive, even when faking to goof up.

I know that this may sound counterintuitive, but it's not that easy to deliberately ruin a shot for the sake of demonstration - much less bracketing multiple upon multiple goof ups. It's not what one would imagine, given how little effort it normally takes to goof up... and I should know, since I goof up all the time! But to ruin a shot purposefully requires a measure of effort and considerable forethought. Too much error, and the image becomes useless. Too little error, and it offers nothing of value. And if that isn't enough, the ruined image is still required to follow compositional norms. In other words, each sample image has to appear as if effort was undertaken, despite the obvious goof up I'm trying to fake.

Such is the burden of testing, for the sake of dumb curiosity.

It really was burdensome! I took many many shots. Too many in retrospect. I thought I had to, in hindsight. There were many exposure and lighting situations to consider. But then it occurred to me while sorting through the piles of images - it wasn't necessary to post every example. Beyond the absurdity in scope, it would most likely be too overwhelming if not confusing. For me to communicate my findings effectively, I must be concise, otherwise redundancies will dilute any impact in demonstration.

So, to dumb things down a little, I decided to edit my sort. For example, we do not need to start this comparison from a baseline of proper exposure, lower ISO or normal lighting situation. We don't need to do this because we have already seen how the Leica M10 and Leica SL renders image taken properly in optimal conditions. What needs to be seen is a comparison of images, taken in suboptimal conditions, then fixed in post.

In conducting the shoot for this comparison, I decided on a more controlled environment. It made sense, given the needs of the shoot. We needed a closed environment where swapping lenses between camera would be easier. We needed a location where we could easily control the light conditions. And rather honestly, we just wanted a change in location, where the background would hopefully offset the banality of deliberately botched exposures. We kind of needed a change from shooting on the street. We needed to shoot indoors.

Immediately coming to mind would be a more colorful interior - hot red for instance. I love hot red. There is just something deeply absorbing that draws me to it, like a colorblind bull to a bullfighter just asking to be gored. Red is a color that always gets my attention.

Unfortunately, Anna forgot her red lipstick.

She also forgot to bring the mounting plate of the tripod she borrowed. So all the shots for this shoot had to be done hand held. Even so, a lack of consistency in camera position did not waver my spirits. That is because I found an indoor location very hot in red. I liked it so much that I decided to stay for an additional two days, for the sake of our next two articles.

I do love hot red.

The lens I selected for this shoot was the Leica APO 50mm f/2 Summicron ASPH, since I had two examples with me. So much for swapping lenses. As for my sorting, I've limited it to three typical shooting situations.

1. Low light to test high ISO under normal use
2. No light to test dynamic range under high ISO
3. Extreme backlight to test dynamic range (underexposed and overexposed)

SET 1 - LOW LIGHT OUT OF CAMERA RAW

Leica SL - ISO 50,000 - Out of camera RAW

Leica M10 - ISO 50,000 - Out of camera RAW

Leica SL - ISO 25,000 - Out of camera RAW

Leica M10 - ISO 25,000 - Out of camera RAW

Leica SL - ISO 12,500 - Out of camera RAW

Leica M10 - ISO 12,500 - Out of camera RAW

SET 2 - NO LIGHT TEST OF HIGH ISO DYNAMIC RANGE

TEST 3 - EXTREME BACKLIGHT TO TEST HIGH ISO DYNAMIC RANGE

(A) OVEREXPOSED

Leica SL - ISO 25,000, -2.5 stops, same added contrast, saturation, vibrance, and clarity

Leica M10 - ISO 25,000, -2.5 stops, same added contrast, saturation, vibrance, and clarity

Leica SL - ISO 6400, -2.5 stops, same added contrast, saturation, vibrance, and clarity

Leica M10 - ISO 6400, -2.5 stops, same added contrast, saturation, vibrance, and clarity

(B) UNDEREXPOSED

Leica SL - ISO 6400, +3 stops, similar added contrast, saturation, vibrance, and clarity

Leica M10 - ISO 6400, +3 stops, similar added contrast, saturation, vibrance, and clarity... plus notice the lens flare defect of the early release APO 50!

Before I continue with my evaluation, I must admit that I did start this comparison with considerable bias. Having tested the Leica M10 over the last three weeks, I have come to the conclusion that the M10 is the best camera ever! How could it not be? It is extremely forgiving in low light given the improved high ISO and dynamic range. Furthermore, the M10 also rendered color better than the Leica SL. The M10 had more of a 3D pop, while the SL appeared flatter in rendering. So like an impetuous child with a new toy, I had rather impulsively forsaken the Leica SL. With that said, I still had to verify my premature conclusions with this comparison.

Well, long story short, I couldn't have been more wrong.

Although at correct exposure, I still maintain that the M10 renders color better. But push dynamic range of an underexposed image two to three stops at high ISO, and it becomes abundantly clear that any gains in tonal range will fade away. Under those conditions, the Leica M10 appear to retain less details than the Leica SL.

As for retaining details of incorrect exposure under extreme backlighting, the dynamic range of the Leica SL appears to also perform better underexposed when pushed a couple of stops. But to be fair to the M10, the results were tainted by the lens flare defect of the APO 50. Still, the SL appears to retain details better than the M10.

The same can be said of the SL when overexposed and pulled a couple of stops. Again, the dynamic range of the SL appears to retain details better than the M10. However, it should be noted that making that determination wasn't immediately clear. It did take me some looking to be certain, but then I saw the details retained in Anna's eyes. That tipped the balance in favor of the the SL over the M10.

As for retaining details of overexposed highlights under direct sunlight at high ISO, I forgot to do that comparison. Alright, I goofed for real! However, if we were to extrapolate an answer from our existing backlit test shots, it would appear as if the Leica M10 isn't significantly better or worse than the Leica SL. Both exhibit more or less the same amount of clipping, and both appear to be able to retain details when overexposed by 2.5 stops. However, beyond that 2.5 stops, details are no longer recoverable.

A final note on usage. In pitch darkness or when the subject is blackened by extreme backlighting, it is impossible to focus on the subject with a rangefinder, like the M10. However, with the EVF of the SL, focusing under those extreme conditions is possible, given exposure simulation and focus magnification. It is not always about high ISO, dynamic range, and color rendering.

Last - I am going back on my word. I said I wasn't going to post any base line images. But I also promised many images with hot red background, which apparently, I haven't. So below are a set of images captured at high ISO and typical low light conditions.

Worth adding is the fine tuning of the exposure in post. Apparently, the flickering incandescent light source had a significant impact in exposure.

APPENDIX - HIGH ISO UNDER COMMON LOWER LIGHT CONDITIONS AT CORRECT EXPOSURE

Now that I've posted this baseline too, it does give me a better understanding why the Leica SL is better at high ISO and dynamic range. Clearly the evidence of horizontal banding is clearer on the M10 than on the SL. But with that said, the color rendering of the M10 is warmer and noticeably more pleasant, especially with regards to the shadows in skin tones.

I do love hot red. I love the Leica M10. And I still love the Leica SL.

Overall, the evidence would support the conclusion that the Leica SL has better high ISO and dynamic range than the Leica M10. In retrospect, this should not have been a surprise. There was actually a hint of that posted in the Part I preview of this comparison. I guess bias made me dismissive. All the more reason to conduct a comparison. And if not for the sake of verification, then just dumb curiosity, I guess.

Admittedly, there wasn't as much hot red as I had intended for this post. I guess I will have to remedy that in my next two posts. So please stay updated.

All comparisons used the same exposure settings except for the shutter speed. For some unknown reason, the Leica M10 required an additional stop of light in order to capture the same render as the Leica SL. All images were photographed with the APO 50mm f/2 Summicron ASPH - although the one fitted on the M10 was an earlier edition with the lens flare defect. All the images on this post were optimized at varying degrees on Lightroom, unless stated otherwise. None of the images were cropped (except of the title image).

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