Help with ETTR Please...

frugivore wrote in post #16642089
So that makes me wonder why the OPs camera was set to ISO 400 instead of increasing it. Perhaps a flash was on the hot shoe?

Simple. Either OP wants to keep it low to control the noise, or he wasn't using auto ISO and was wondering what the lo exp warning is about.

frugivore wrote in post #16642089
So that makes me wonder why the OPs camera was set to ISO 400 instead of increasing it. Perhaps a flash was on the hot shoe?

OP, if you are using the camera's auto exposure, it may overexpose or underexpose the scene, depending on the scene's dynamic range. So you will need to dial -EC when the scene has a wide dynamic range or +EC when the scene had a narrow dynamic range. Or none at all.

I use auto Iso and set a min shutter speed of 250/sec and 400Iso as i belived this was the highest Iso i should use due to the noise generated by the sensor, this is quite good and accurate combined with matrix 11 metering in setting a quite acceptable result, however there is no control over noise with this setting, that is why i add anything between 1/3 and 1 stop of EC as i was under the impression that this was ettr.
Would i be better off sellecting a higher Iso(manuly) say 800 and over exposing via EC say to 1 full stop, then just shoot normaly, or do as i do now and use auto that genarly defaults to 100Iso when the lighting is good enough or other wise it can sellect all sort of Iso speeds including intermediate settings 125,160,320 etc.
I have read that setting full Iso steps of say 1000 Iso and letting as mutch light hit the sensor, results in a cleaner image than one at 100 Iso and underexposing slightly-not over exposing?

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I have gone over my raws in Lightroom and checked their histograms and most show a middle ground collection of exposure information, so i moved the exposure slider to +1.50 and see in most of my pics that the histogram info collects from just before the middle and towards the right, and in most cases isnt clipping, im not saving like this just testing to see if this meens a + 1.5 exposure increse would benefit my sensor.


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vengence wrote in post #16640712
Yes, I am saying if you are moving your histogram to the right while shooting, and then back to the left in post (in addition to your normal post processing), you've clipped the 1 stop of dynamic range off the top of your sensor and decreased the dynamic range. Now, in reality it's a good thing that you do! There's very little to no data you want in that range (as you've clipped stuff to the right of the highlight peak in your histogram). The trade you are making (since nothing is free) is all of your shadows and blacks will be less noise prone because they are over exposed before your post processing.

That is not the case. You only lose that dynamic range at the top of your sensor as you put it if you are clipping highlights.

HOWEVER if you have a mid toned scene with some deep shadows that you may want to brighten out in post to match the way your brain has processed it when you see the scene, exposing to the right is loses nothing. You'll need to change exposure in post to suit your tastes but you haven't lost any DR - you've just made the most of the sensor.

When you have a scene with a very large DR, it will be more difficult, but the best approach if you aren't printing SOOC is still to expose as far to the right as possible until just before any highlights you want to keep clip off. Some have been calling it exposing to the left but in reality they are still exposing to the right for the tolerable amount of clipped highlights

I have also disscoved my camera is biased towards preserving the highlights so underexposes abit anyway.

Im trying to discover a Safe Zone for getting the best noise free files, that could be used as a bench mark and slightly adjusted as needed, for example if i set my exposure to + 1 and use a higher Iso but a normal full one 200,400,800 etc say 800, this would give me more exposure adjustment room to toggle my shutter speed/Aperature about, to get as much light on the sensor and hopefully get a less noisey image.


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Pagman wrote in post #16642232
I have gone over my raws in Lightroom and checked their histograms and most show a middle ground collection of exposure information, so i moved the exposure slider to +1.50 and see in most of my pics that the histogram info collects from just before the middle and towards the right, and in most cases isnt clipping, im not saving like this just testing to see if this meens a + 1.5 exposure increse would benefit my sensor.


P.

If your camera was set to ISO 400 and you moved the Exposure slider to +2.0, you in effect increased ISO to 1600, but not in a good way. LR and the camera don't change ISO in the same way. LR does it digitally and the camera does it analogically by using a tiny amplifier to boost the signal strength. Digital make more noise than analog, at least in the lower ISOs up to 1600. Raising Exposure that much in LR is something to be avoided if the ISO involved is less than 1600 because it is bad for noise. But in the same way decreasing Exposure into the minus numbers reduces noise. If you expose as high as possible (without clipping) you get to drag down the tones in LR and kill some noise.

tzalman wrote in post #16642437
If your camera was set to ISO 400 and you moved the Exposure slider to +2.0, you in effect increased ISO to 1600, but not in a good way. LR and the camera don't change ISO in the same way. LR does it digitally and the camera does it analogically by using a tiny amplifier to boost the signal strength. Digital make more noise than analog, at least in the lower ISOs up to 1600. Raising Exposure that much in LR is something to be avoided if the ISO involved is less than 1600 because it is bad for noise. But in the same way decreasing Exposure into the minus numbers reduces noise. If you expose as high as possible (without clipping) you get to drag down the tones in LR and kill some noise.

Thank you, that was just a slider pushing test afterwards i set it back to as it was shot, i just wanted to see if clipping would occur at 1.5 times additional exposure adjustment, and i think i may get away with setting +1 to 1.5 stops of EC in the camera as a normal procedure, bu wonder what i can/should do with the Iso to aid my exposure room of shutter speed and aperature and at the same time improve noise reduction.

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In M
Set aperture based on desired DoF
Set shutterspeed based on subject motion blur constraint
Set ISO so histogram just touches right edge of display.

(Use UniWhiBal if needed)

AJSJones wrote in post #16642764
In M
Set aperture based on desired DoF
Set shutterspeed based on subject motion blur constraint
Set ISO so histogram just touches right edge of display.

(Use UniWhiBal if needed)

Thanks for the comment but not realy relavent, when out in the field with subject matter moving quickly, by the time i did the adjustments you mentioned, what i wanted to shoot would have been long gone, what i seek is a general rule of thumb, that i could use to help keep noise at bay.

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AJSJones wrote in post #16642764
In M
Set aperture based on desired DoF
Set shutterspeed based on subject motion blur constraint
Set ISO so histogram just touches right edge of display.

(Use UniWhiBal if needed)

^this. Although you can adjust ANY of the parameters as needed keeping the others fixed where you need/want them.

Sheesh, quit overthinking this stuff and go take photos. I often think that some people spend so much time trying to perfect such meaningless issues that they never really learn to take photos.

Pagman wrote in post #16642785
Thanks for the comment but not realy relavent, when out in the field with subject matter moving quickly, by the time i did the adjustments you mentioned, what i wanted to shoot would have been long gone, what i seek is a general rule of thumb, that i could use to help keep noise at bay.

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There is no absolute rule of thumb.

Set your iso as high as you are comfortable (400). Set your aperture to the sweet spot of the lens (say, f8). If you want to let your shutter speed float, go for it. If you find that you are getting too slow of a SS then you need to adjust something else.

Once you are generally set up, take a picture. Look at the histogram. If you want to ETTR then add EC until the histogram touches the right side. THAT'S IT. Go. Do it.

Edit: depending on the subject, the metering mode, the framing, changes in lighting etc things will change. You can't do anything about that. Sometimes you just have to do the work and compensate for those changes. Quit letting the camera try to figure out what you want.

Here are two examples shot just, both handheld at 55mm available light no flash, both 1/6th second and f4.5 the first one is Iso 800 and with 1.5 stops of EC added in camera, the second is a base 100 Iso shot with no additional EC added but brought back up about 2 stops in post.

Both 100% crops

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Copidosoma wrote in post #16642805
There is no absolute rule of thumb.

Set your iso as high as you are comfortable (400). Set your aperture to the sweet spot of the lens (say, f8). If you want to let your shutter speed float, go for it. If you find that you are getting too slow of a SS then you need to adjust something else.

Once you are generally set up, take a picture. Look at the histogram. If you want to ETTR then add EC until the histogram touches the right side. THAT'S IT. Go. Do it.

Edit: depending on the subject, the metering mode, the framing, changes in lighting etc things will change. You can't do anything about that. Sometimes you just have to do the work and compensate for those changes. Quit letting the camera try to figure out what you want.

I do appreciate that and sometimes i aggree, but other times you do not have the time to flaff about, if you are sitting comfy taking a landscape almost like you are painting it then yes you would have the time to almost measure the scene for light and contrast and perhaps shoot several shots and keep adjusting till your happy, if your shooting something very fast and sudden like a fighter jet jumping at you from round a corner,or an animal suddenly coming into sight and moving away just as fast, it just One chance you get not a second chance.

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^^ so what's your verdict?

And how about doing a 3rd shot with the correct exposure and no EC?

kin2son wrote in post #16642860
^^ so what's your verdict?

And how about doing a 3rd shot with the correct exposure and no EC?

What do you see -more noise in the 100Iso shot ?

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