Roxie2401 wrote in post #12839892
Well, either I didn't do it right or.......but when I set the cursor to a point in the image (example:RGB=255,255,255) and then typing a 1 or 2 in the brightness box - the image changed but the RGB values remained the same.
I do see the effect of the Linear function, too.
Hmm, odd, I don't remember it acting that way when I was messing with it before, but I just checked and you are right, the RGB figures stay the same unless you either click or move the mouse. Dang, that doesn't make sense. You don't want to click the mouse because then the active point moves out of the little text box.
But, try doing this: hover the pointer over part of the scene with a smooth tone, making the numerical change, then just wiggle your mouse a smidgen -- the numbers should go to the revised number.
Now, was I supposed to do this in the RAW tab brightness and not the RGB tab?
Well, the RGB tab and the Raw tab seem to act differently from each other and I'm not an expert in DPP and can't really give an analysis of it all, so I guess it's a matter of experimenting. I don't know how extensive the learning materials are about DPP and how much exploring various people have done. I've just mostly done quick messing around with it. Of course the Linear option is not available with a jpeg/in the RGB tab.
Also, "Expose to the Right"???? Do you mean to go on the overexpose or + side? And, can that be done successfully with the Exposure Compensation + on Canon cameras like the 7D? For some reason I thought underexposing was better for retaining detail?
Expose To The Right (ETTR) is a technique that is specific to digital and in paricular to Raw shooting. It takes advantages of one of the strengths of digital Raw files in order to combat one of the weaknesses of digital.
A digitital Raw file will retain all "good" light as long as the signal is not "blown" -- as long as your R, G and B channels stay within the 255 clipping point, then they will retain both accurate color and tonal information. This means that all image info is retained and can be worked with, and if, say, you have a shot that you used a bit of Exposure Compensation (or the Manual equivalent) to bump the exposure a bit so where it was a bit brighter than seemed "normal" when viewed, as long as there was not highlights clipping or color channels clipping then in post processing if you lower the brightness setting a bit you will have the "proper" exposure without losing anything.
Now, as to the weakness of digital, the fact is that digital noise is "picked up" by the sensor in any ISO. This noise is not necessarily visible when the exposure has gotten plenty of light, because the light "drowns out" the visible noise. But, the less light picked up by the sensor, the more likely it is that noise will be visible, especially if the low-light scenes are then amplified. This is why a high ISO scene tends to show more noise than a low ISO scene -- the ISO operation amplifies the combined light and noise, and if little light is collected, then more noise will be visible. It's also why in post-processing if you take a nice dark shadow and boost the brightness of it with your processor, eventually you will see noise, and this is true of any ISO -- if you have an ISO 100 image that has a deep dark area that you really want to lighten up and you boost those shadows by 3 or 4 stops, you will see that ISO 100 isn't quite what we may have expected!
So, the solution to this digital noise is to let in more light so that we have as much range as possible to work with shadow areas without getting messed up with noise! This is what has caused the ETTR topic to be of interest amongst digital photogs, especially for those of us who do a lot of outdoor shooting in challenging light -- if you can increase your exposure a bit without blowing out highlights, you are letting more light into those dark areas, and the result is you can work with those shadow areas without as much noise becoming visible and, because of that capability of digital imaging that I spoke of above, you can lower the brightness of your image and it will accurately retain the color/tone info that would be considered "right".
Raw shooting has several strengths, and this is one of them -- for example, a Raw file will hold all the details captured by the camera, including highlight detail, that is in danger of being discarded by the camera if you shoot jpegs. This ETTR technique takes advantage of that. With jpegs, I'd advise sticking with your best "normal" exposure but for Raw shooters this can be a powerful technique when needed. For me it's usually just a matter of bumping my exposure a bit until I either see highlight "blinkies" or I see one of my RGB channels hitting the end of the histogram.
I also have my Picture Style set to Neutral and the Saturation and Contrast set to the lowest level (-4). This is because the histogram and the highlight alerts use the RGB "rendering" of the camera (that which produces a jpeg) and will give misleading readings (too high) for highlights and colors. If you are working with a challenging scene and looking to ETTR, then you can use all the help you can get, and getting a bit more viible accuracy in your exposure aids gives you a bit of help!
Also, know that Canon cameras have an interesting "undocumented feature", (which for some is a shortcoming). Canon as well as the other companies have put a lot of work into producing "clean" images, especially at high ISOs. Canon has "led the pack" in this up until a couplle of years ago when Nikon and Sony finally "got it" and now they are all competing in this area. Well, a "little problem" has come to light -- Canon evidently hasn't made this effort equal across all ISOs. In fact, it has been shown that the amplifiers used in the lower ISOs do, in fact, generate a bit more noise than those used in the higher ISOs.
What this means is that it is inaccurate to assume that you can underexpose an image in a lower ISO and then boost it by say, one, two or three stops and get the same (or better) results as you would get using the ISO one, two or three stops higher.
You can test this dramatically yourself by shooting a scene in Manual (and Raw) that is "properly exposed" at ISO 1600. Make sure things like High ISO Noise Reduction and Highlight Tone Priority are turned off. Avoid dark shadows and blown highlights, get everything showing properly in the histogram, take the shot.
Then, think about this: the high ISO is four stops higher than ISO 100! Now, the thinking above, that the lower exposure will be "OK" might seem at this point extreme, but then there is that "High ISO causes noise!" thinking (that originated in the film world) and so hey, let's put it to the test!
So, since you are in Manual, this is easy -- just lower your ISO to 100 and, since your shutter and aperture are the same, you are good to go. Make sure the lighting is the same (shooting indoors, even at night with "fixed" lighting can help). Think now, the scene will be horribly underexposed but the aperture and shutter will be letting in the exact same amount of light and so the sensor will be collecting the exact same exposure. The only difference between the two images will be the ISO amplifictation. Got that? So go ahead, take the shot! Then here is the fun part -- to load the two shots into your Raw processors and "equalize" them!
In DPP you will actually have to use both your Brightness controls, because neither the Linear nor the RGB Brightness controls will go four stops in one direction. So set your Raw slider to its max (2) and then go to the RGB tab and adjust Brightness until the brightness of the ISO 100 image matches that of the ISO 1600 image. Now, compare the two images! Zoom in and do a noise check and ask yourself, is the ISO 100 image cleaner than the ISO 1600 image? If not, you have learned something valuable!
So, at least with Canon cameras (this can differ with other makes), the use of digital ISO can play powerfully into getting our best results, and has in POTN been merged in with the ETTR methods into a method called "HAMSTTR":
It was fun being part of the discussion that "spawned" that term a couple years ago, check it out!
(Glad you got your 5D back!)
Hey, thanks, so am I!