Color differents in 2 indentical shots

[wparsonsgisnet]

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Theo, I think the problem is that the shutter is faster than the little computer that does the awb. I have had this problem since the M8 arrived.

 

However, I always shoot both a hi-res jpg and a dng. I use the jpg's (1) for backup in case the file does not write correctly, and (2) as images to scrool thru using ICDSee (viewing sw that came with the D2).

 

As it happens, in several thousand shots with the M8, I have had 3 occasions when either the jpg or the dng failed to record on the SD card. I can proudly say that I have one or the other version of these shots. Disclosure: Ansel probably wouldn't have printed them.

 

It's just a computer behind the lens, and it can't always keep up.

 

RAW is the photographers best friend (said often by me, at least).

 

If you only have jpg's you'll have to color correct them.

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[jedi996sps]

Share same opinion as most people have already stated, appears to be a problem with AWB, which hopefully will be addressed in next soft/firmware release. I have to date left my M8 on AWB, problem occurs even when shooting outdoors. What is really fustrating and amusing at teh same time, depending on which day it is, is that i also hav a digilux2 which has not suffered from this problem. Perhaps 2 different software programmers wrote the algorithms for each camera!!! :-)

[stunsworth]

I've seen this a couple of times shooting RAW with AWB when I've taken two shots _very_ close to each other. The second shot has always been too cool as above. Fortunately it's very easy to correct in the RAW conversion stage.

[jedi996sps]

I've seen this a couple of times shooting RAW with AWB when I've taken two shots _very_ close to each other. The second shot has always been too cool as above. Fortunately it's very easy to correct in the RAW conversion stage.

 

Excuse my ignorance...which is probably why i havn't tried it thus far. But, what typically do u hav to do to a RAW file before printing it.

 

Generally, i hav to out of necessity, adjust the WB in the jpegs, all of which are taken on the M8's standard settings.

 

(apologies to original poster for hijack)

[jaapv]

What is really fustrating and amusing at teh same time, depending on which day it is, is that i also hav a digilux2 which has not suffered from this problem. Perhaps 2 different software programmers wrote the algorithms for each camera!!! :-)

 

The Digilux2 has an external WB sensor.

[stunsworth]

...what typically do u hav to do to a RAW file before printing it.

 

Occasionally the white balance. Normally I make adjustments to the black/white points and constrast. Occasional I may use the recover option if highlights are close to blowing. I use Adobe camera raw for all of this. It's a lot less complicated than it may sound.

 

The other thing is that any RAW files I process are opened as 16 bit files. Although the RAW files from the M8 aren't true 16 bit - I believe they're 12 bit - this gives more headroom when processing them and decreases the chance of posterisation.

 

I usually use the Alien Skin Exposure plug-in once the RAW file has been processed and opened. For colour I normally use the plug-in's Astia preset. This adds a little 'snap' to the file without going over the top like Velvia. If I'm printing b&w I'll use whichever of the presets gets me nearest to how I want the print to look. Sometimes that can be the Tri-X setting, sometimes the Acros one.

 

Finally before printing I'll use the Photokit sharpener software to add the appropriate sharpening before printing

 

As I say, once you have established a way of working that you're happy with, all of the above only takes a few minutes per printed image.

[wparsonsgisnet]

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... what typically do u hav to do to a RAW file before printing it. QUOTE]

 

Ali, as mentioned I always shoot dng with jpg. I use C1 to process the raw files. I also try to shoot a WhiBal card as a gray reference, but when I haven't done so I try to find a gray in the image.

 

I was surprised, when learning to use C1, that the first step in the process is WB. After I worked with it a little bit, I came to feel it was very sensible.

 

C1 is used by some enormous monsters, here. Real pros.

 

When I include a gray card, or when I choose a gray area in the image, after this when doing the wb it is possible to see the effects and judge them. You can also save this gray "profile."

 

So, when I do a studio shoot, I shoot a gray card everytime I change the lighting, or camera setting. Later, I record the location of the gray cards (image numbers) for my post-processing. Then I know that image 1764 has the gray card for all images until the next gray card. I keep these notes in my processing notebook.

 

While the strange results from the awb might make people nervous, every single one of my raw images color balances properly.

[ho_co]

... Normally I make adjustments to the black/white points and constrast. ...

 

Steve--

Could you give (or point me to) a brief explanation of what black point and white point are? I work a fair amount with Photoshop but have always been afraid to mess with them because I don't understand their purpose.

 

Thanks.

 

--HC

[stunsworth]

The easiest way is to open up a levels adjustment layer. You'll see a histogram with three upward facing triangles just below it. If you move the left triangle to the right you'll see the darker parts of the image darken more. What is happening is that all the values in the picture that now lie to the left of the triangle are now black.

 

The opposite happens if the move the triangle on the bottom right to the left. In this case all of the values to the right of the triangle are now white.

 

This is what I mean by adjusting the black and the white points. There are other ways of doing this. I use the curves adjustment. With CS3 the curves adjustment also shows you the histogram and you can see the effect of what you are doing on it.

 

Quite often when you open an image you'll see that the shape of the histogram looks like an inverted 'U'. This means that the image has no strong blacks ans whites, and quite often this can lead to the image looking rather flat and low in contrast. There are of course exceptions to this. By adjusting the black and white points you can make the image look more natural with more 'punch'.

 

The advantage of using adjustment layers is that you can revisit the image later and remove any changes you may have made by either deleting the layer, or changes its values. In effect adjustment layers give you access to non-destructive editing.

[Guest Bernd Banken]

Howard,

 

in this link to the famous scanning software "Vuescan" there is a good explanation of the use/influence ot the black/white points:

 

http://homepage.mac.com/onelucent/VS/vsm.html

 

Just scroll to the middle of the explanation.

 

Cheers

Bernd

[thpeters]

Fortunately it's very easy to correct in the RAW conversion stage.

 

Yes Steve asn Bill, it is easy to correct in RAW and I shoot RAW also, still it ignores me, and I think more users that it happen with a camera like this.

 

Simple said Leica or who is doing the software should fix that.....period.

 

Happy shooting all of you.

 

Theo

[jedi996sps]

... what typically do u hav to do to a RAW file before printing it. QUOTE]

 

Ali, as mentioned I always shoot dng with jpg. I use C1 to process the raw files. I also try to shoot a WhiBal card as a gray reference, but when I haven't done so I try to find a gray in the image.

 

I was surprised, when learning to use C1, that the first step in the process is WB. After I worked with it a little bit, I came to feel it was very sensible.

 

C1 is used by some enormous monsters, here. Real pros.

 

When I include a gray card, or when I choose a gray area in the image, after this when doing the wb it is possible to see the effects and judge them. You can also save this gray "profile."

 

So, when I do a studio shoot, I shoot a gray card everytime I change the lighting, or camera setting. Later, I record the location of the gray cards (image numbers) for my post-processing. Then I know that image 1764 has the gray card for all images until the next gray card. I keep these notes in my processing notebook.

 

While the strange results from the awb might make people nervous, every single one of my raw images color balances properly.

 

 

Thanks Bill,

I guess the answer is i should try the dng+jpeg. I hav photoshop already but will look at C1 too. I hav to date balanced within PS using the dropper tool for white and black.

As u might guess i am new to all this and hungry for info, so this forum is great for me. I did a search as well and now hav some idea's that i will try to get better results out when printing.

 

Ali

[ho_co]

Thanks, Steve & Bernd, for the pointers and link.

 

Ali--

Digital is so new that I think many of us are inexperienced at some aspects of this stuff, particularly considering how frequently any piece of software gets updated.

 

That's why we're all here.

 

--HC

[DaveSee]

AWB, including the presets may very well be at issue. Bill points out and interesting effect of the shutter, others about using a manual technique(ExpoDisc) with a decidedly non-manual(fixed) preset. Interesting too is your choice of "cloudy" with 5500K lights and flash... isn't "cloudy" more in the 6000-6200K range? And is the flash that accurate to reach the same color temp in 2 seconds?

 

I've used the Kelvin settings from 11 Nov '06 and f/w 1.06 with never a drift of temp between shots. I also do not ever use "Auto Review". I am not suggesting that presets and other AWB methods in-camera are a poor method, nor the use of "Auto Review": yes, these software processes should just work... or be removed for their inconsistent/poor performance. I just have too little trust in "Auto Anything"--no, I do not use A mode for the shutter either--and I try to keep the in-camera software out of my process(that's a data purity concern, and between the lens and sensor). But then, I share my lenses with an M4 and now you know medieval lifestyle

 

Theo, if in a studio with reasonably controlled lighting, why do you use AWB or presets?

You are correct that the firmware needs some work, but why let some programmer decide the WB(and with presets and Auto it's done for each shot at shutter release)?

 

rgds,

Dave

[wparsonsgisnet]

... i should try the dng+jpeg. I hav photoshop already but will look at C1 too. I hav to date balanced within PS using the dropper tool for white and black.

...

 

Ali, you can balance in PS just fine. If you're shooting raw, you can do the same stuff with the raw module.

 

Someone else here can tell you haw to save the setting and/or apply them to multiple images at the same time. This is probably covered in my book on PS2, as well, but I haven't read that part yet.