BetterPhoto Q&A
Category: New Answers

Irene Troy

Confused about RAW and exposure

I am confused about what happens when shooting RAW. I understand that by shooting in RAW format that I have more control over the final image and that not until I actually open and “develop” the image in the RAW converter does the image become an image. This morning I was out trying to capture images of birds. I set my Canon 5D to capture in RAW & Medium Jpeg. I set the shutter speed between 125 and 200 to maximize sharpness despite the breeze and the movements of the birds. Because it was early (around 6am) and overcast with heavy haze the TTL meter kept telling me that the exposure values were underexposing the images. I maintained the settings and pretty much ignored the flashing numbers indicting an underexposure. I am now editing those images and noting that the Jpeg images are very underexposed and in some cases they are so dark it is difficult to see the bird. The RAW images are near perfect in exposure and there is little editing required. I understand that the TTL meter can be totally off in many shooting situations such as when the light is very contrasty or when the light is low. In my situation the light was pretty even with the heavy haze. I went with my gut and shot the images at a speed that would capture the bird without fuzziness and allowed the camera to set the corresponding f-stop and when this failed, I switched back to manual and simply set the shutter speed to what I needed and let the f-stop reading come close to the center line of exposure. What I don’t understand is why the Jpeg images are so very underexposed while the RAW images are near perfect exposure. Can someone explain this to me? Thanks!

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June 23, 2006

Jane M

Irene - the JPG image is derived from exactly the same RAW image you are looking at. So that implies that the in-camera jpeg conversion settings are different to the conversion settings you are using in your RAW file viewer.

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June 23, 2006

Susan L. Vasquez

The converter most likely is auto correcting your original image. When I open my RAW images in CS2, it does this. Sometimes it is a good thing, sometimes not.

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June 23, 2006

Kerry L. Walker

"I am confused about what happens when shooting RAW."

If I shot in the RAW it would be called indecent exposure. I would probably get arrested if anyone could stop laughing long enough to call the police. LOL

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June 23, 2006

Irene Troy

Damn Kerry! I decided to check my e-mail before heading to lunch and now I can’t stop laughing!

Susan – what you said makes the most sense to me. I have noticed this happening ever since I started shooting mostly RAW and just never really thought about it until this morning. The difference between my Jpeg images and the RAW was so extreme this time that I could not help but notice the changes. Interesting – I keep learning so much from this site! Thank you.

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June 23, 2006

Christopher A. Vedros

"The converter most likely is auto correcting your original image. When I open my RAW images in CS2, it does this."

This just doesn't seem right. Why bother shooting in RAW if the image is going to be auto-corrected?

I've been shooting RAW for quite a while now, and I've never noticed any difference between the exposure of RAW and JPG images coming from my camera. I don't use PhotoShop, so I don't know how the RAW converter works. The image editor that I use opens the RAW files directly, it doesn't convert them first.

Irene - have you tried opening your RAW files in Canon Digital Photo Professional? It should be on the disc that came with your camera. Then you'll see what the RAW files look like without any correction.

Regardless of RAW's wider latitude, you'll always end up with a better final image if you know that you are starting with the right exposure.

Chris Vedros

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June 23, 2006

Susan L. Vasquez

Well, Chris this is true. Always best to have the correct exposure to begin with...but if it doesn't happen then CS2 tries to correct it. Thing is it doesn't always do the best job. Usually I end up manually setting the corrects myself.

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June 23, 2006

Christopher A. Vedros

Okay. As soon as I hit submit, I thought of something else.

Irene - have you been playing around with the image parameters in your camera? If you've adjusted settings to make the JPG image come out too dark, those same parameters won't be applied to the RAW image, which is not processed by the camera.

So the RAW image would be showing that your exposure was correct, while the JPG image is being made too dark.

Could that be it?

Chris Vedros

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June 23, 2006

Slim Brady

Raw images are always corrected unless you turn off the settings. While in bridge if you go to each box and un-check it you will see how you actually shot it.

Oh what a gift it is. Just what an amatuer needs to save their but. Which the pros aren't super happy about. But hey, just imagine how many real artist will come out of the woodwork and sink the technical guys (who think they are artsy :)

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June 23, 2006

Irene Troy

From the direction this thread appears to be heading I thought I’d better clarify my question: I understand that PS-CS2 converts images from RAW into a final output file – most often TIFF format (at least in my case). I also understand about auto-correct; although, until you told me about it, Susan, I did not know this. I also understand that the data from a RAW file is more extensive than the data in a Jpeg file – thus the opportunity to tweak images post capture. And, Chris, your point is very well taken – it is a mistake to rely upon any post-capture software to make your image. PS-CS2 is one powerful piece of software, but even it cannot make a poor image good.

What I have trouble “getting” is why even prior to opening a RAW file and viewing the image in Adobe Bridge or Canon Photo Pro the RAW file looks substantially different than the Jpeg file. Chris, I think that you may have given me a place to look when you suggest checking the image setting in camera. That would, of-course, explain everything. Thank you for that idea.

One thing that all of this is teaching me is that I can trust my gut more than I thought. My instinct told me to ignore the little annoying flashing numbers on my camera that kept telling me that the image would be underexposed and to set exposure how my eye told me. Once again the human eye and brain over performs the digital brain! Thank you everyone for your input!

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June 24, 2006

Sharon Day

I have PS CS and the RAW converter doesn't do a thing to the image until I make changes. It always displays exactly as shot when I first open it. I don't think I'd like the program doing an auto adjust. I'm looking at the RAW converter now. It doesn't seem as though CS has an auto adjustment. At any rate, I can't find it.

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June 24, 2006

Bob Chance

Irene,

Except for intentionally setting the exposure compensation dial to under or over expose your shot, there is nothing I know of in the menu parameter that would alter the exposure of jpg images in such a way. Usually the parameters that can be changed are contrast, saturation, sharpness and color tone.
These parameters affect all images redardless of jpg or RAW. This can be noted in DPP. Take a shot with all the settings in their neutral position. Now, adjust those parameters intentionally. Load and open both images in DPP and bring up the RAW editing window. You will note that the optional settings each will reflect what the camera parameters were set for.
I thought that RAW was not affected either, but I changed me parameters from setting 1 to setting 2. Differnce being number one everything is neutral. In position 2, sharpness, saturation and contrast are all adjusted to level one. When I opened up these pictures in DPP, the first thing that caught my eye was the sharpness slider was at one, when normally it has always been on zero. The reason being was because of the changes made in the parameters of the camera.
As far as why your jpg's are so much darker than the same RAW images, I have no idea unless it has to do with photoshops algarythms when it converts your RAW images. I don't know if PS converts as soon as you load an image or after you've edited it. In DPP, the conversion doesn't take place till after you've edited and choose to convert and save the image either as jpg or tff (8 or 16bit).

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June 24, 2006

Irene Troy

I am trying to put this in words that won’t sound either nasty or ungrateful for all the advice and insight everyone has offered on this topic. However, nothing that has been said seems to answer my question or clear my confusion. This is probably my own fault, so here are two images that may show what I am trying to understand better than my words. Other than slight cropping to eliminate a pole, nothing has been done to either image. The RAW example was simply opened not adjusted.

I understand that it is possible to set in-camera perimeters that will alter an image as that image is made either as a Jpeg or RAW; however, since this is a new camera I have yet to alter any default settings and after checking those settings I have confirmed that nothing is being done to alter the image in-camera. I also double checked my PS settings to ensure that when the RAW image is opened it is opened without inadvertent adjustments. Therefore the image should be as shot. I tried opening the RAW image using Canon Digital Photo Pro and the differences between the Jpeg image and the RAW image – pre-adjustment – appear as they do in PS. So, I am back to the beginning question: what is going on?

None of this is really a problem, I generally use the Jpeg image as a reference and use RAW to create the final image post-adjustment when needed. I am just curious and a little confused as to why the Jpeg image appears so much darker than the RAW one. Anyway, thank you, again, everyone who has contributed their thoughts and ideas.