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12-26-2007, 08:13 AM   #1
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Shooting Raw but want to adjust EV 1/3 darker?

Shooting Raw but want to adjust EV 1/3 darker?

Can I set this into the menu to adjust EV for RAW pictures or is this only for JPEGS?

I can adjust the EV button using the front dial. If I adjust it to -.5, then if I shoot a -.5 bracket, does that add teh EVs? E.g. -.5 on the bracket with EV set to -.05 is a picture @ -1?

thanks


Last edited by rdrum76; 12-26-2007 at 08:28 AM.
12-26-2007, 08:28 AM   #2
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I believe this works for RAW. However, I think you have to control the exposure via either holding the button on the BACK (AE? maybe) and then the front wheel. The exposure will be shown on the top dial for the k10. Its the same way you would use to change the ISO, but instead of the OK its a different button.

Someone let me know if this is incorrect.
12-26-2007, 08:53 AM   #3
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Just remember that shooting digital is analogous to shooting slide film.

Shoot to the right (you want the highlights to be almost clipped). Expose for the highlights not the shadows.

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Last edited by PDL; 12-26-2007 at 08:54 AM. Reason: wording
12-26-2007, 08:56 AM   #4
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QuoteOriginally posted by rdrum76 Quote
Shooting Raw but want to adjust EV 1/3 darker?

Can I set this into the menu to adjust EV for RAW pictures or is this only for JPEGS?

I can adjust the EV button using the front dial. If I adjust it to -.5, then if I shoot a -.5 bracket, does that add teh EVs? E.g. -.5 on the bracket with EV set to -.05 is a picture @ -1?

thanks
Yes, you can do it, but I would suggest that you do it in post processing. As mentioned by PDL, the hardest part of the digital image to retain is the shadow detail. I tend to shoot right on the edge of blowing out the highlights. I turned on the "blinkies" and try to shoot so that I have just one tiny specular highlight blinking. This seems to give me the most image detail. I can then darken the photo in Lightroom, but still have all the shadow detail in the image.

12-26-2007, 09:11 AM   #5
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CJ thanks; yes for the K10D you are right; the ISO trick is cool too

CR thanks; it is important to retain shadow detail; b/c if I simply EV down, all I have is darkness it is better to shoot for detail and then tweak in PP
12-26-2007, 09:44 AM   #6
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QuoteOriginally posted by PDL Quote
Shoot to the right (you want the highlights to be almost clipped). Expose for the highlights not the shadows.
Almost but not clipped.
12-26-2007, 09:50 AM   #7
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QuoteOriginally posted by rdrum76 Quote
Shooting Raw but want to adjust EV 1/3 darker?

Can I set this into the menu to adjust EV for RAW pictures or is this only for JPEGS?

I can adjust the EV button using the front dial. If I adjust it to -.5, then if I shoot a -.5 bracket, does that add teh EVs? E.g. -.5 on the bracket with EV set to -.05 is a picture @ -1?

thanks
So, this question indicates that a review of exactly what EV compensation does is in order.

There's three variables that affect exposure -- shutter speed, aperture, and ISO. All of these are fixed when you take a picture -- there's no way to change them later. (While you can shift bits around to simulate an increase or decrease in ISO, you can't get back clipped or blown details.)

The camera's program modes attempt to calculate the correct value for these variables to match the metered scene. (Many of the program modes, like Av and Tv, let you determine one or two of the variables and only calculate the remaining ones.)

When you set EV compensation, what you're doing is changing the target value for the camera's exposure calculation. Since this will result in a different shutter speed, aperture, or ISO (or perhaps all three), it's clear that RAW and JPEG are both affected.
12-26-2007, 01:22 PM   #8
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Matt, you raise a point that I am interested in getting answered. what do you mean by "clipping"? Are you saying shooting digital, I should be slightly overexposing the picture and really lightening up the highlites for best results? If that is the case, I am exposing backwards underexposing rather than overexposing. I tend to get lots of dark areas in my pics that have the flashing colour dots. I tend to get that even with no compensation letting the camera use its own calculations. But that is another sotry. That may have a lot to do with what my exposure meter is centering on i.e. centre weighted etc.

12-26-2007, 01:37 PM   #9
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Clipping is when you have exceeded the maximum brightness (or minimum brightness) recordable by your camera in that shot. Those flashing color areas in the preview are indicating where clipping has occurred.

When something is clipped, your camera is registering 255,255,255 or 0,0,0 on the RGB scale for that region. This is important because that's means details are being lost. Even if you shoot in RAW, clipped areas will never show additional detail.

Our minds analyze shadows a lot more than highlights. As a result, biasing our shots to slightly over expose will cause more highlight details to be given up (which our minds won't really miss) and gain more details in the shadow areas (which our minds will pick out).

Hope that helps.
12-26-2007, 11:17 PM   #10
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QuoteOriginally posted by Mapleleaf-Mick Quote
Matt, you raise a point that I am interested in getting answered. what do you mean by "clipping"? Are you saying shooting digital, I should be slightly overexposing the picture and really lightening up the highlites for best results? If that is the case, I am exposing backwards underexposing rather than overexposing. I tend to get lots of dark areas in my pics that have the flashing colour dots. I tend to get that even with no compensation letting the camera use its own calculations. But that is another sotry. That may have a lot to do with what my exposure meter is centering on i.e. centre weighted etc.
I try to expose so that I get one very tiny highlight (red blinkie) warning, such as on a sun reflection on chrome, or one tiny area in a white cloud. If I am really worried about highlight details, the I will back off the exposure until the red blinkies just barely stop. I hope this helps.
12-27-2007, 12:41 AM   #11
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Thank you Albert and Avant for that explanation. It really helps. I guess this leads to a question on technique. Do you purposely over/under expose by bracketing say +1, 1, -1 when you shoot? Would this process give me that little bit of "clipping" we were referring to? What technique to you two use to maximize the amount of detail you get in the shadow areas? Do you take test shots and then look at the histograph, blinking areas etc.? Thank you very much for imparting your knowledge.
12-27-2007, 07:55 AM   #12
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QuoteOriginally posted by Mapleleaf-Mick Quote
Thank you Albert and Avant for that explanation. It really helps. I guess this leads to a question on technique. Do you purposely over/under expose by bracketing say +1, 1, -1 when you shoot? Would this process give me that little bit of "clipping" we were referring to? What technique to you two use to maximize the amount of detail you get in the shadow areas? Do you take test shots and then look at the histograph, blinking areas etc.? Thank you very much for imparting your knowledge.
Bracketing is good. I'll throw a bit more into this by asking what detaila do you want to preserve? Sometimes you may sacrifice the highlights, sometimes the shadows. This will be the scene and your choice. Don't overthink this too much. Personally, it's a bit better to be "underexposing" a tad than over, esp w/ a K10 that seems to go out quite quickly at highlight saturation (so the saying should be "expose to the left of right a bit", but that is more confusing than it needs to be. And keep in mind different colors go out faster than others as well. ie RED....
Noise in the shadows (caused by underexposure) usually cleans up better and easier than false colors caused by blowout of highlight areas. You got all good advice from the prev answers but none (including mine) can hold up for all images..............
Nice little overview......
A PRACTICAL GUIDE TO INTERPRETING RGB HISTOGRAMS - Interpreting your digital camera's thumbnail image and histogram
12-27-2007, 11:35 AM   #13
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QuoteOriginally posted by Mapleleaf-Mick Quote
Thank you Albert and Avant for that explanation. It really helps. I guess this leads to a question on technique. Do you purposely over/under expose by bracketing say +1, 1, -1 when you shoot? Would this process give me that little bit of "clipping" we were referring to? What technique to you two use to maximize the amount of detail you get in the shadow areas? Do you take test shots and then look at the histograph, blinking areas etc.? Thank you very much for imparting your knowledge.
I often bracket. I often bracket when I think I know the best exposure, and find that I am off just a little bit. With the k10d it is so easy to put it into bracketing mode, and so inexpensive (How much does the extra battery recharge cost for 4 extra frames?) just to make sure.

For my own personal use, I put the brackets into exposure order, rather than the default. The default is 0, -1, +1, -2, +2 (at one stop intervals), but I prefer -2, -1, 0 , +1, +2, although I might just reverse that because I am finding right now, in winter, that it is the + side that is better.

An option with the k10d (and other bodies) is to set the exposure compensation to where you think the exposure will be better - such as +1.5 or +2 when shooting with lots of snow in the picture, and then bracket around that exposure. When doing this I will bracket at smaller intervals.
12-28-2007, 08:04 AM   #14
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I've quit worrying about slight under/over exposure conditions. Many of the shots from opening presents Christmas morning clipped both the shadows and the highlights. I know it's not ideal, but if I'd set for +Ev, the highlights would have been worse, and if I'd set for -Ev, the shadows would have been worse. I guess this is my realization that the K100D doesn't have the highest dynamic range, but it certainly is still workable. I find that very slight PP adjustments of the histogram on the y axis usually fix the clipping issues. Pentax Photo Lab makes this quite easy, as you can see the flashing clipped areas just the same as on the camera's LCD.

I'm extremely amature, but I just don't see any other way to not clip highlights and/or shadows in a some situations.
12-28-2007, 11:41 AM   #15
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QuoteOriginally posted by code4code5 Quote
I've quit worrying about slight under/over exposure conditions. Many of the shots from opening presents Christmas morning clipped both the shadows and the highlights. I know it's not ideal, but if I'd set for +Ev, the highlights would have been worse, and if I'd set for -Ev, the shadows would have been worse. I guess this is my realization that the K100D doesn't have the highest dynamic range, but it certainly is still workable. I find that very slight PP adjustments of the histogram on the y axis usually fix the clipping issues. Pentax Photo Lab makes this quite easy, as you can see the flashing clipped areas just the same as on the camera's LCD.

I'm extremely amature, but I just don't see any other way to not clip highlights and/or shadows in a some situations.
That's your choice of course to not bias your exposure. However, it does not mean there are no other options available.

Using a smaller aperture and higher ISO are ways to reduce contrast within a scene. Another effective method of reducing contrast it to use a fill flash (flash on low power). This can lift the shadows without interfering with the bright areas of the scene.

There isn't a consumer camera in the world that can match the dynamic range of our eyes yet, so that's a realization you should acknowledge for all cameras (film and digital).

There was also a thread recently that also discusses how increasing exposure reduces large amounts of ISO noise in shadow areas.

As mentioned before, clipped areas will not show detail no matter how much post processing you add. You can adjust the photo in post processing so that the image does not appear clipped on the histogram, but those previously clipped areas will still not show additional detail.
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