AWB Surprise

[pthompson]

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I did a search, but found no info on how the AWB functions (other than badly) on the M8. I generally use presets or custom WB, but I was showing a friend how quirky the AWB was, and when I opened the DNGs in ACR, I was amazed to see that there were only three WB settings in 'as shot', no matter what the lighting conditions were - temp/tint 3900/+12, 5900/+9, and 7400/+8. To check this, I took AWB shots outside, sun and shade, and inside in fluorescent, tungsten, combo, and with and without window light added. No matter the condition, these were the only 'as shot' settings that appeared in ACR - and yes, with most shots the balance would swing wildly between warm and cool, with no change in camera settings.

 

Has everyone else known this all along, or is this true only with my camera??

[Mark_Schretlen]

I did a search, but found no info on how the AWB functions (other than badly) on the M8. I generally use presets or custom WB, but I was showing a friend how quirky the AWB was, and when I opened the DNGs in ACR, I was amazed to see that there were only three WB settings in 'as shot', no matter what the lighting conditions were - temp/tint 3900/+12, 5900/+9, and 7400/+8. To check this, I took AWB shots outside, sun and shade, and inside in fluorescent, tungsten, combo, and with and without window light added. No matter the condition, these were the only 'as shot' settings that appeared in ACR - and yes, with most shots the balance would swing wildly between warm and cool, with no change in camera settings.

 

Has everyone else known this all along, or is this true only with my camera??

 

I agree. I noticed the same thing with my M8 although the values are different (only because I am using a different RAW converter - C1) they fall into three distinct WB values. It's as if someone at Leica decided there are only three different color temperatures allowed in AWB and one has to be "daylight", one has to be "tungsten", and the last has to be "cloudy". Its like they decided that there are no other posssible color temperatures.

[Guest WPalank]

Maybe I'm not following you correctly. "As Shot" is not THE setting (but it is at the top of the menu), it is one of many choices that should be in the dropdown menu for "White Balance".

I checked out PS just now, and have the whole gamut of choices in the drop down menu.

 

I'm using CS3, if that makes a difference.

[pthompson]

Maybe I'm not following you correctly. "As Shot" is not THE setting (but it is at the top of the menu), it is one of many choices that should be in the dropdown menu for "White Balance".

I checked out PS just now, and have the whole gamut of choices in the drop down menu.

 

I'm using CS3, if that makes a difference.

 

Sorry if I am not clear - what I mean is that the 'as shot' values never vary from these three possibilities, even though the conditions under which the shot is taken covers a vast range of color temperatures. My other cameras at least attempt to respond to the particular conditions, even if often unsuccessfully...

[zlatkob]

It seems like a crude way to design AWB. I hope the next camera is more sophisticated with its AWB.

[pthompson]

It seems like a crude way to design AWB. I hope the next camera is more sophisticated with its AWB.

 

Really. You would think that you could have at least the half dozen options that are on the menu. So I expect that the long awaited 'fix' for the WB will be that the camera will make the simple-minded choice with some accuracy - not that there will be a more sensitive range of possibility.

 

I feel a little sheepish whining about this, since one of my reasons for getting the M* is to get back to a more direct photography experience...If I wanted AWB, I'd use my 5D anyway.

 

My motivation really is to find out if my camera is functioning as intended...

[bradreiman]

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I feel a little sheepish whining about this, since one of my reasons for getting the M* is to get back to a more direct photography experience...If I wanted AWB, I'd use my 5D anyway.

 

My motivation really is to find out if my camera is functioning as intended...

 

how are the photographs? if you like em the camera is functioning as intended...b

[pthompson]

how are the photographs? if you like em the camera is functioning as intended...b

 

This is silly - do you really think it is intended that two shots of the same subject matter in the same light should yield color temperatures 3000 or 4000 degrees difference? My question was - is this the way other people have found that their M8 functions (or malfunctions) or might I have a particular problem with my camera that I should have checked out?

[ken_tanaka]

Yes, the M8's "AWB" has become known as "Awful White Balance". Leica has acknowledged that the M8 uses Flintstones AWB code (little more than a table-looker-upper, rather than a true image analysis) and promises improvement one day.

 

Here's a perfect example of the M8 picking, apparently randomly, between two fixed white point settings for its "auto white balance. These images were shot within a minute of each other under exactly the same light and camera / lens settings. Pretty, eh?

 

 

But I'm not holding my breath for a better M8 AWB system. Modern AWB code is highly proprietary between manufacturers, quite sophisticated, and constantly in flux with camera model changes. Leica is unlikely to be able license a generic solution and even more unlikely to get their own version built any time soon. So I expect that their M8 solution will be to simply add more rows to the looker-upper table.

 

Personally, I use one of the presets for my shooting. It makes batch adjustments much simpler and has produced far better results for me. I suggest giving it a whirl, Barney. (Err, I mean Peter.)

[pthompson]

Personally, I use one of the presets for my shooting. It makes batch adjustments much simpler and has produced far better results for me. I suggest giving it a whirl, Barney. (Err, I mean Peter.)

 

Thanks, Ken, for the samples and for the advice. I actually have been using presets, and, when possible, shooting a gray card for my WB. I discovered the 'three sizes fits all' approach only last weekend...

[mjh]

when I opened the DNGs in ACR, I was amazed to see that there were only three WB settings in 'as shot', no matter what the lighting conditions were - temp/tint 3900/+12, 5900/+9, and 7400/+8.

Now that would certainly explain the apparently random fluctuations observed – with just three settings to choose from, small differences in the outcome of the image analysis could lead to completely different WB settings.

[Philinflash]

With all due respect, Peter, I think you are confusing the white-balance feature of the in-camera software (firmware) with the white balance adjustment feature of your post-process software on your computer; they are two different things. You have noticed that the FW options in the camera are different from the WB adjustment options in your computer software. That should confirm for you the above. If you had access to software applications other than that which you are already using, you would see further options differences.

 

When your computer's post processing software offers "As Shot" as the default option, it really means as the the file came to the computer from the camera. Hence, if you had made adjustments to the capture white balance values when you took the picture, those values will be imbedded in the file when you open the file using your computer's software and will be "As Shot." Thereafter, whatever white balance adjustments you make on your computer will be modifications of the imported capture file. There is no connection between the options in your post-process software and the firmware options in the camera.

 

Another way to think about this is that the FW WB governs characteristics of the capture BEFORE the shot is taken and the PP WB governs charateristics of the capture AFTER the shot has been taken and once the file is in the computer.

[Mark_Schretlen]

With all due respect, Peter, I think you are confusing the white-balance feature of the in-camera software (firmware) with the white balance adjustment feature of your post-process software on your computer; they are two different things.

 

I don't think Peter is confusing anything. I think that he has made an important observation about the M8's AWB, one which explains why the AWB appears erratic. Ken illustrates the effect and mentions that Leica uses a "table-looker-upper" for the M8's AWB. Peter is just saying that there are only three values in this table. If the same Leica engineer implemented the same system for the M8's auto-exposure, it would precisely measure the EV and then set the shutter speed to either 1/1000 or 1/100 or 1/10. You can have anything you want as long as it's just these three.

 

As seen in other discussions on this board, no one seems too bothered by this AWB behavior (is this Leica "user glow"?). Those of us that have used other digital brands have become accustomed to AWB that is reasonably well behaved and are a little surprised at Leica's neophyte implementation. I think they would have been better off removing the AWB option completely - after all, this is effectively what users have adopted as a workaround.

[wparsonsgisnet]

I don't think there is a lack of bother here and, though an avowed Leica lens lover, I think my and others' postings are pretty even-handed.

 

Most here -- and many agree the WB is problematic -- use RAW. At the time I began using the M8 I learned to WB my pix. Up until then I suffered. Because I began to use C1, and because the first thing it does is handle the WB, I changed the way I work.

 

So, if Leicaphiles can complain here, I'd like to have a change. As far as I am concerned, the word raw means a core-dump from the sensor. That's NOT what we get.

 

I would like NO compression of the raw file. Also, the color balance of the raw files has changed with different versions of the firmware. That's troubling. Gimme the pixel values.

 

As the price for this I willingly surrender buffer space, storage space, and write time.

 

In any case, shoot raw.

[pthompson]

I don't think Peter is confusing anything. I think that he has made an important observation about the M8's AWB, one which explains why the AWB appears erratic. Ken illustrates the effect and mentions that Leica uses a "table-looker-upper" for the M8's AWB. Peter is just saying that there are only three values in this table. If the same Leica engineer implemented the same system for the M8's auto-exposure, it would precisely measure the EV and then set the shutter speed to either 1/1000 or 1/100 or 1/10. You can have anything you want as long as it's just these three.

 

As seen in other discussions on this board, no one seems too bothered by this AWB behavior (is this Leica "user glow"?). Those of us that have used other digital brands have become accustomed to AWB that is reasonably well behaved and are a little surprised at Leica's neophyte implementation. I think they would have been better off removing the AWB option completely - after all, this is effectively what users have adopted as a workaround.

 

Thanks, Mark. You explained what I was saying much better than I did. It is hard to figure out why Leica would bother designing such a primitive system - after all, those of us that love to work with the camera don't care that there is no AF; we wouldn't have cared if there was no AWB, either. But I was also amazed that they would have released the camera with the IR problem, and then taken months to produce the filter solution (which, from my point of view, was perfectly workable).

[Jamie Roberts]

{snipped}

So, if Leicaphiles can complain here, I'd like to have a change. As far as I am concerned, the word raw means a core-dump from the sensor. That's NOT what we get.

 

I would like NO compression of the raw file. Also, the color balance of the raw files has changed with different versions of the firmware. That's troubling. Gimme the pixel values.

 

As the price for this I willingly surrender buffer space, storage space, and write time.

 

 

Bill, as Oscar Wilde says, "the truth is rarely pure and never simple."

 

Raw files, when you see them in a program like C1, have a host of changes over the per-pixel values.

 

The most important is gamma correction. Otherwise, what you would see is, well, not much: raw sensor data is linear, and unfortunately (or fortunately) we don't see things that way.

 

A Bayer sensor also produces a mosaic of monochromatic file values. They need to be interpreted somehow: first by the software and then tweaked by a colour matrix (which Leica changed for the better IMO) or an input profile.

 

So unless you're using DCRAW or the equivalent, you will never, ever, ever see "per pixel values".

 

Finally, the compression on the M8 is controversial. Is it lossy or lossless? Effectively lossless?

 

I don't know. I *do* know the files are better in a lot of regards than any other digicam I've used.

 

I personally would not want 20MB files to slow down the M8 more than it is, and I'd love to have the option of Leica's compression scheme on my DMR.

 

As for average white balance, yes, it's broken. Yes, they could take it off the menu till they fix it

 

No, it's not a big deal to me: in RAW no-one cares; in JPEG you should set it first anyway--even if you're using a Canon.

[pthompson]

When your computer's post processing software offers "As Shot" as the default option, it really means as the the file came to the computer from the camera. Hence, if you had made adjustments to the capture white balance values when you took the picture, those values will be imbedded in the file when you open the file using your computer's software and will be "As Shot." Thereafter, whatever white balance adjustments you make on your computer will be modifications of the imported capture file. There is no connection between the options in your post-process software and the firmware options in the camera.

 

Another way to think about this is that the FW WB governs characteristics of the capture BEFORE the shot is taken and the PP WB governs charateristics of the capture AFTER the shot has been taken and once the file is in the computer.

 

Phil - The only thing that confuses me is what your understanding of the word 'Auto' means in AWB, and what 'As Shot' means in the conversion software. One doesn't make in-camera adjustments to the WB when using the AWB setting...so the values in 'As Shot' would quite logically be those that the camera supplied as an automatic white balance.

 

I realize that this might be much too much time to spend on something most of us claim to not care about.

[charlesphoto99]

I don't think there is a lack of bother here and, though an avowed Leica lens lover, I think my and others' postings are pretty even-handed.

 

Most here -- and many agree the WB is problematic -- use RAW. At the time I began using the M8 I learned to WB my pix. Up until then I suffered. Because I began to use C1, and because the first thing it does is handle the WB, I changed the way I work.

 

So, if Leicaphiles can complain here, I'd like to have a change. As far as I am concerned, the word raw means a core-dump from the sensor. That's NOT what we get.

 

I would like NO compression of the raw file. Also, the color balance of the raw files has changed with different versions of the firmware. That's troubling. Gimme the pixel values.

 

As the price for this I willingly surrender buffer space, storage space, and write time.

 

In any case, shoot raw.

 

I do shoot RAW. I doubt anyone working with the M8 doesn't. That's not the point. When the clock is ticking, it's nice to know that one can get away with minimal p.p. before showing results to the client. It's worked for the Canons/Nikons I've shot - why can't it for my $5K Leica. Yes, it's easy to change WB in p.p. but it's even easier not to have to!

[Julius Bjornsson]

I just checked 30 or 40 photos from diverse conditions all taken with AWB. I just get three values in CR, 3900, 7400 and 5900. I think this is unbelievable but I am also happy to have an explanation for the very bad auto white balance. So my simple conclusion is, never to use AWB. How could they even consider putting out the system like this, these guys must have access to cameras from the japanese competition. Very very strange.

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Hallo,

Look here: Leica M

[wparsonsgisnet]

,,, most important is gamma correction. Otherwise, what you would see is, well, not much: raw sensor data is linear, and unfortunately (or fortunately) we don't see things that way.

 

A Bayer sensor also produces a mosaic of monochromatic file values. They need to be interpreted somehow: first by the software and then tweaked by a colour matrix (which Leica changed for the better IMO) or an input profile.

 

I personally would not want 20MB files to slow down the M8 more than it is, and I'd love to have the option of Leica's compression scheme on my DMR ... QUOTE]

 

Jamie, thanks for the very clear explanation of the first two items. I agree with you that the color balance for raw is better.

 

With regard to compression, of course it should be optional. Glad to know that you think enuf of it to want the option on the DMR as well.

 

BTW, I was doing some shooting last night in a dress rehearsal of one (astonishingly lovely) dance that my wife made for some young women at Boston University. In order to play nice in front row of the darkened theater, I turned off the picture review. During this session, I had NO buffer fill-up's. I will experiment this weekend and will report on this further, but if the picture review has been causing me to have buffer fill-up problems, then there's a new workflow in my future.