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Leica M sensor low light performance state of the art?


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Were does the Leica M 240 stand in terms of noise etc?

 

Here is some interesting information showing that the read out noise has improved compared to the M9 but it is stall lacking in comparison with most Nikon and Canon full frame sensors.

 

Sensorgen - digital camera sensor data

 

I don't know wheter the data are directly related to DXOmark

 

Interestingly, the read out noise is getting worse at higher ISO in contrast to e.g. that of the Nikon and Canon Sensors. So I suspect that underexposoure at ISO 800 and pushing in Photoshop gives better results than exposure at ISO 6400

 

Thomas

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The problem with these type of figures -including DXO- is that they are not taken from the pure sensor output but from the raw data which include pre-raw noise reduction by the firmware, which will vary per camera. Leica traditionally applies little or no preprocessing, Nikon for instance quite a bit.

 

So these data are fine as far as camera output goes within their limited scope, but to judge the real difference one should use optimally processed comparison images taken side by side etc.

 

Only then one can see the differences in amount of noise - weirdly taken as the sole criterion for image quality in some circles, imo the least important one-, colour rendering, contrast and dynamic range, amount of detail, etc.

 

I have not seen this kind of meaningful comparisons yet.

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So let's concentrate solely on the Leica M results. What is interesting, the read out noise increases with increasing ISO setting, there is no other camera in the list showing this effect. Therefore, as I said, in oder to obtain the best low light performance ISO 800 and underexposure by 3 stops shoud give better results than ISO 6400, not very much but half a stop or so.

 

Thomas

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It suggests to first apply a proper amount of noise reduction to the Leica DNG files and then compare the outcome to other sensors (that had the noise reduction already as part of the in-camera raw processing as explained above).

With the results after noise reduction in hand you can then compare with pushing ISO 800 DNG files in post-camera development.

All other discussion is based on assumptions only.

 

Maarten

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It suggests to first apply a proper amount of noise reduction to the Leica DNG files and then compare the outcome to other sensors (that had the noise reduction already as part of the in-camera raw processing as explained above).

With the results after noise reduction in hand you can then compare with pushing ISO 800 DNG files in post-camera development.

All other discussion is based on assumptions only.

 

Maarten

 

1. What is know about preprocessing of raw data on the chip? Does the most recent models still make use of it? Or is it just a myth or speculation?

 

2. The ieda of underexposure and pushing in postprocessing, I was not suggesting to compare in first place to other brands, the idea was comparing results just using different ISO settings of the M.

 

Thomas

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Guest malland

dwbell, don't understand why it's ironic when it's relevant: somewhere around page 5 or 6 of the thread you linked Jim Kasson talks about how the technique discussed in that thread (maximizing the M9's IQ by shooting at ISO 640 and pushing in LR4/5) could be applied to the M-Monochrom — he surmises that for the M-Monochrm the technique would probably be to shoot at 1250 and push in post. It would be interesting of he could test the M240 in this respect. I'd be interested in how Jim responds: it would be good if he could post here.

 

—Mitch/Paris

Tristes Tropiques [WIP]

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Guest malland

colonel, you need to read Jim Kasson's article, which is linked and explained in post #1 in the thread that dwbell linked above. In the article, Jim discusses the results of tests he rant with the Nikon D4, 800E and the Leica M9. The title of the article is ETTR — just crank up the ISO? Not so fast.

 

—Mitch/Paris

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Would be interesting to hear Jim Kasson's view on the OP's linked data. I'll ping him a PM....

 

I'd rather analyze my own data, given the choice. I received an M240 last night. I've got family obligations until after Labor Day, but I'll start testing then. When I have results, I'll post links to them here.

 

Jim

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doesn't this imply that lightroom (or whatever you use) is doing a better job then the camera's firmware/amplifier ? and why would this be the case ?

 

Yes, Lightroom does a better job at reducing high ISO noise than any camera by itself. Lightroom's Process 2010 introduced fantastic noise reduction, much better than that in the prior Process 2003. Process 2012 improved it even further. It is phenomenal. I don't know the technical details, but I believe Lightroom utilizes a lot more computing power (in a desktop or laptop) than a camera can. Lightroom also has the luxury of time; it can process a raw file for a longer duration (if needed) than a camera can or should.

 

Lightroom has effectively made all digital cameras better for shooting at high ISO and better when the exposure needs to be pushed in post. However, cameras retain their relative advantage/disadvantage for shooting at high ISO. So those that were excellent to begin with are even more excellent with Lightroom.

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1. What is know about preprocessing of raw data on the chip? Does the most recent models still make use of it?

 

I suppose there could be some kind of noise-reduction pre-processing of the raw data that wouldn't show anomalies in SNR testing at various ISO settings and photon counts, but I'd be heard pressed to know what it could be.

 

In my testing of the Sony NEX-7 and RX-1, the Nikon D800E and D4, and the Leica M9, I've only seen evidence of such processing at ISO 6400 on the NEX-7. Here's a link to those results.

 

Jim

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Guest malland
...Lightroom has effectively made all digital cameras better for shooting at high ISO and better when the exposure needs to be pushed in post. However, cameras retain their relative advantage/disadvantage for shooting at high ISO. So those that were excellent to begin with are even more excellent with Lightroom.
While that is of course true, for the M9 I find the improved IQ using the "Shoot at ISO 640 and push in LR4/5" technique to be, in effect, a refutation of the conventional wisdom that the M9 is not useful for high ISO. The reason that I say that is that I like very much the M9 color rendition of the night shots taken with this technique. Indeed, I have received several e-mails from people who told me that they sold their M9s because they were not able to do night photography that they liked with it.

 

I'll be very interested in seeing the results of Jim Kasson's tests with the M240. Because the M240 is better at high ISO than the M9 (apart from the color rendition, in my view), this improvement in IQ from this type of technique may be less compelling. However, it could be still important because the dynamic range goes down as you push up the ISO in-camera and this technique could turn to be very useful for that purpose. When I get a chance, I'll try this technique with the M-Monochrom, whose dynamic range goes down significantly at really high ISO.

 

—Mitch/Paris

Tristes Tropiques [WIP]

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It is always good to know techniques that push the quality little bit further, but I am pretty happy about what LR already does to images shot at ISO6400. Below is a link to a screenshot of shadow area of an image shot with M at ISO6400 - left, opened in LR5 and right, opened in RawDigger, which does not apply any NR. I dialed deliberate amount of luminance noise reduction (44) in this particular screenshot, but even with no luminance noise reduction the image looks good (grainy, but no color noise).

 

http://elsners.org/misc/lr5vsrd.png

 

My only concern at ISO 6400 is banding. Not sure if the technique of shooting at ISO800 and underexposing might help.

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I'd rather analyze my own data, given the choice. I received an M240 last night. I've got family obligations until after Labor Day, but I'll start testing then. When I have results, I'll post links to them here.

 

Jim

 

Thanks for popping in Jim. Look forward to your results, when you have time.

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When I said I'd not seen evidence of in-camera noise reduction of raw values in the Nikon D4 and D800E, I was not considering dark-current-based long exposure noise reduction, which many cameras employ, or, indeed, any long-exposure noise reduction algorithms. I apologize if that unstated omission caused any confusion.

 

Jim

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Guest malland
It is always good to know techniques that push the quality little bit further, but I am pretty happy about what LR already does to images shot at ISO6400...
I haven't shot with the M240, but have shot at ISO 5000, 8000 and 100000 with the M-Monochrom and, while the noise is not often an issue, the dynamic range can be very thin; this is significant, because at those low light levels, when there is all sorts of mixed lighting, getting the right exposure can be difficult. Shooting with the technique under discussion, the exposure is pushed in LR4/5 only to the level needed and the dynamic range is also better, which simplifies this type of shooting a lot in street photography.

 

—Mitch/Paris.

Tristes Tropiques [WIP]

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