Dark frame noise reducing

[towander4343]

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The Leica SL automatically creates a dark frame to work around the issues of noise in long exposure images. This is all well and good but it doubles exposure time. Is there a manual over ride so you can do this manually. If not why?

 

Many thanks in advance.

[thighslapper]

no ......and if you fancy a 1hr exposure using the remote cord you will have a 1hr NR exposure wait as well. I know, I've tried .... and given up ....

 

Leica's standard excuse in the past has been 'to preserve image quality' 

 

which is fair enough ..... if you haven't by that stage beaten the camera to bits in frustration at the tedium of waiting, waiting, waiting .....

 

that degree of 'image quality preservation' equates to 'not bothering to take the picture at all' as far as I'm concerned, so it hasn't achieved very much .....

Edited January 7, 2016 by thighslapper

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[ramarren]

Yes, there should be an override. Another firmware enhancement request... 

[jaapv]

The dark frame noise reduction cannot be matched by post-processing. It is an illusion to think that switching it off and using Dfine or such could match the result. In fact, without the dark frame (one could see it momentarily on the M8) the image looks awful.

I am sure that those clamoring for an override would use it - once  and never again.

[AlanJW]

no ......and if you fancy a 1hr exposure using the remote cord you will have a 1hr NR exposure wait as well. I know, I've tried .... and given up ....

 

Leica's standard excuse in the past has been 'to preserve image quality' 

 

which is fair enough ..... if you haven't by that stage beaten the camera to bits in frustration at the tedium of waiting, waiting, waiting .....

 

that degree of 'image quality preservation' equates to 'not bothering to take the picture at all' as far as I'm concerned, so it hasn't achieved very much .....

If you don't take any photos you cannot make any bad ones.  You can also save thousands of dollars that way. 

[Jared]

The dark frame noise reduction cannot be matched by post-processing. It is an illusion to think that switching it off and using Dfine or such could match the result. In fact, without the dark frame (one could see it momentarily on the M8) the image looks awful.

I am sure that those clamoring for an override would use it - once  and never again.

 

 

No, but I'd love to be able to build a master dark frame for the same temperature at the end of the evening, for example, rather than having to take separate darks after each exposure.  I do this all the time with my astronomy cameras and get much better results than I ever could with a single dark.  Of course, astronomy cameras are generally temperature regulated, but I'd still like to be able to turn the feature off so I could capture star trails and the like.  

 

- Jared

[J S H]

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No, but I'd love to be able to build a master dark frame for the same temperature at the end of the evening, for example, rather than having to take separate darks after each exposure.  I do this all the time with my astronomy cameras and get much better results than I ever could with a single dark.  Of course, astronomy cameras are generally temperature regulated, but I'd still like to be able to turn the feature off so I could capture star trails and the like.  

 

- Jared

 

Agreed completely. Leica needs to give the users a choice on long exposure noise reduction. Every other full frame camera I have used (Canon, Sony, Nikon, etc) gives you the option to disable LENR. I suspect the SL would perform about the same as other recent full frame cameras, all of which are completely usable without LENR.

 

And yes, you can definitely improve on forced sequential LENR performance by building a master dark frame with 4-5 exposures at the end of the shoot.

[忘不了]

JJPG format should be automatic noise reduction, when the choice of DNG should be closed automatically noise reduction function. Save time for shooting and catch up with good scenery.

[jaapv]

Not a bad idea, to limit automatic DFNR to JPG situations and make it optional in DNG.

[towander4343]

I think the very wording "In camera Noise Reduction" is misleading, as has been pointed out the dark frame is only taking away hot pixels. Perhaps it should be called something like DFS for 'dark frame subtraction'. Anyway the point is we should be able to turn it off and not be forced to have it on each and every image. Incidentally I wrote to Leica UK about this issue and whilst they acknowledged my email about a week ago they have yet to reply.

[jaapv]

Well, given that this discussion has been running since late 2006 without Leica relenting, I somehow doubt that the reply will bring anything new.

[Jared]

Unfortunately, I suspect you are right. Too bad. In an effort to improve image quality in long exposures Leica is actually damaging our ability to better address hot pixels through a master dark (average of several dark frames taken at the end of the imaging run then applied to all light frames). The result is increased noise vs. what we could do if we could just shut off mandatory dark frame subtraction.

 

- Jared

[LocalHero1953]

I have always understood that Leica puts the photographer on control, not the camera. This policy doesn't make sense. If it did we would be forced to stick with jpgs processed in camera, and not allowed to use raw files. This isn't a rational approach, it's just stubbornness.

[jaapv]

Quite likely true. However, stubbornness has gotten Leica where they are now

[towander4343]

I just got an official response from Leica saying they hope it will become available in a new firmware update. as a keen Nikon user I'm following up on this for a family member. I can honestly say the current lack of an on/off switch would definitely stop me from buying the SL.

[helged]

Interesting! Certainly looking forward to the FW update, although things may take time...

[忘不了]

Open up this feature after a lot of people have bought, because you can shoot the star.

[DezFoto]

no ......and if you fancy a 1hr exposure using the remote cord you will have a 1hr NR exposure wait as well. I know, I've tried .... and given up ....

 

 

At least you can do a long exposure... (us M240 owners can't   )

[FlashGordonPhotography]

At least you can do a long exposure... (us M240 owners can't   )

 

 

Or S.... not even the 007. This and LENR are the number one reasons I don't shoot Leica exclusively.

 

Shouldn't it be up to me whether I shoot for the ultimate IQ or accept some reduction in IQ for increased functionality?

 

I've done 8 mins without LENR on my Pentax and the results were great. I have 24" prints. I've done 22 mins with a separate dark frame added in post and the results were great. But my Leicas with their stunning optics stay at home because they are functionally hobbled.

 

Gordon

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[conger]

Interesting arguments!

 

I opened this in another thread ---> http://www.l-camera-forum.com/topic/265418-long-exposures/

 

I appreciate that L are only wanting to see the goody-goody side of their camera by building in corseting restrictions, the ones which some engineer thinks are 'best'.

 

But, we customers have a right to 'see the dark side' and judge ourselves what we like.

 

I frequently take pictures (D700 / D800) in extreme environments, some long exposures (>100 min). The LE pics from the very cold environments are fine (for me!) without LENR; the ones from hot environments are borderline, and benefit from the LENR dark frame... PITA wait!

 

The real answer is to open the camera firmware interface to public use; my filius is into this with Canon cameras. The solution is a simple BASIC or PYTHON interpreter that, for example, allows..

• take pic_1 (parameters provided either automatically, or by operator)
• take pic_2 (parameters provided either automatically, or by operator)
• take pic_3 (parameters provided either automatically, or by operator)
• BEEP 3 times (the camera can now be dismounted -- display message on screen)
• take LENR_frame
• subtract LENR_frame from pic_1 to produce refined pic_1
• subtract LENR_frame from pic_2 to produce refined pic_2
• subtract LENR_frame from pic_3 to produce refined pic_3
• BEEP 10 times (the camera can now be switched off / used again)

BTW... using scripts enables exposure time >> than the 30s offered by the camera FW.

 

Another interesting use case is taking a number of dark frames and subtracting them; one can learn a lot about the sensor quality (over time)   ;-))

 

Yes... I know some of the above can be achieved in PP, but I would prefer to use the camera's own facilities to reduce platform complexity / sources of error.

 

Anyways... there is always the new Hasselblad!

 

-g-