How to improve exposure?

Hmmm... I'll cut&paste to an editor to print this for my collection of notes.

Maybe I can find someone with a drone to give some sort of target in lieu of a buzzard, hawk, owl, or UFO. ;D

i agree full factory reset is the way to go, and start a fresh

That's a good point. The noise produced by a sensor is pretty much constant. In good light that noise is overwhelmed by the signal so you don't see the noise. As the light decreases the signal strength produced by the light decreases so the noise become more and more visible. It's the same effect that happens with a sound amplifier which produces a steady amount of hiss. When the sound is loud the hiss is inaudible but when the sound gets very low you can hear it. That's why it's referred to as signal to noise ratio.

tbcass said:

AlwynS said:

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Fantastic shot. You took advantage of a rare opportunity.

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Thanks Tom. I am very fortunate in that this nest is a brisk 20 minute walk from home. This means it is easy for me to walk there once or twice a day if I wish. From their behaviour I suspect they laid their egg(s) in the first week of March so hoping for some further great photo ops over the next few months until (and hopefully if!) the eggs hatch and they can bring the chicks to fledging. My fingers are still firmly crossed that it all works out....

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Cheers
Alwyn

How do I mitigate the grain shown here? Is this the circumstance for running the EV up?

RBEmerson said:

How do I mitigate the grain shown here? Is this the circumstance for running the EV up?

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Running the EV up will not decrease the noise. It will increase the signal. The end result will be brighter, making the noise count less in comparison.

Basically the rule is that you set EV in the manner yielding the brightness of the end result you desire. Then you set ISO as low as possible (resulting in exposure as bright as possible) in order to get as much signal into the camera as possible and have the noise scaled down in the end result according to the amount of signal you got in.

What blocks are there to lowering ISO? Aperture too wide already (depth of focus), speed too slow already (motion blur), background too bright and in danger of blowing (this is the thing we were talking about right now).

Running the EV up will increase the signal-to-noise ratio but it only makes sense if you actually want the resulting brightness. If you want to stick with what brightness you have, you need more exposure without changing the brightness of the end result. The mechanism is to get slower speed or wider aperture, and the way to get the camera to meter appropriately in the automatic modes is to lower ISO.

So my usual approach is to stick at base ISO, and adjust EV to get the brightness I want. If shutter speed gets too slow or aperture too wide or background too bright and thus in danger of blowing, one has to raise ISO and thus tell the camera to try getting the same result from less exposure. So routinely if I raise EV to cater for backlit subjects, I tend to raise ISO a bit from base ISO in order to be more robust against blown backgrounds.

With regard to photographing against the sky in a fixed position (like an eagle nest), there is another option for reducing backlit subject contrast if you have no shortage of brightness. You can use a polarizer. That costs probably 1EV from everything, but if the sun is sort of at right angles to your subject, you can take out quite a bit of additional light from the sky given the right rotation of the polariser since skylight at right angles to the sun is pretty polarised.

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Would you believe I went to bed last night thinking that this was exactly what I'm going to do today - start all over!

Dak on cam said:

RBEmerson said:

How do I mitigate the grain shown here? Is this the circumstance for running the EV up?

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Running the EV up will not decrease the noise. It will increase the signal. The end result will be brighter, making the noise count less in comparison.

[/ whack!]

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Thanks for the clarification. Also, thanks for more information on using EV.

I admit to a minor(!) brain burp on overlooking a polarizing filter for improving the sky's appearance. It's very much a "don't leave home without it" item. I put mine right behind spare batteries on my "ready to go" list.

In addition to making skies darker, it can also remove much of the specular reflection from a glossy surface. :


Florida gar - Anhinga Trail, Everglades, FL

EDIT: The originally posted photograph has been replaced with an adjusted photograph, altered to show more details in the water. The bleached out lily pads are a consequence of this adjustment. Note, too, some reflections are visible, mainly in the upper left and upper right corners. The change does nothing to alter the CFP's results.

ADDED: Checking the posted version of this photograph, I found two small "Easter eggs" for pixel peekers. There's a second gar in the photograph. Color refraction from shooting into water is visible.

A few points regarding CFP's (circular polarizing filter):

• They're most effective when the sun is directly behind the photographer, or directly in front for water reflections. Shooting at 90° to the light source gives almost no filtering (see wikipedia , etc. for why).
• Not all CFP's are alike. Cost matters less than might be expected. DPR's review of CFP's points to this Lens Rental review. Cut out the middle man and read it directly.
• Removing a CFP can be a problem. Screwed in place, unscrewing the filter may remove, for example, a clear or UV filter in place to protect the front element in a lens. Expect a bit of frustration getting the two apart. Resist the urge to "gorilla" fasten the CFP.

All of that said, CFP's are well worth putting on the "gear I carry" short list.

--
Lead me not into temptation. I know a shortcut.

RBEmerson said:

A few points regarding CFP's (circular polarizing filter):

• They're most effective when the sun is directly behind the photographer, or directly in front for water reflections. Shooting at 90° to the light source gives almost no filtering (see wikipedia , etc. for why).

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This was talking about darkening the sky. The sky is dispersed sunlight, and it is polarised strongest at right angles to the sun. Cf this link.

For more direct reflections on non-metallic surfaces, you get complete polarisation at an oblique reflection in Brewster's angle. The location of the "light source" is not as interesting here rather than that of the mirrored imagery. Usually this reflection angle is pretty close to what you'd pick anyway for getting a surface nicely illuminated but not just flat.

RBEmerson said:

• Not all CFP's are alike. Cost matters less than might be expected. DPR's review of CFP's points to this Lens Rental review. Cut out the middle man and read it directly.
• Removing a CFP can be a problem. Screwed in place, unscrewing the filter may remove, for example, a clear or UV filter in place to protect the front element in a lens. Expect a bit of frustration getting the two apart. Resist the urge to "gorilla" fasten the CFP.

All of that said, CFP's are well worth putting on the "gear I carry" short list.

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If your camera has no beam splitter for a viewfinder and no phase autofocus (just contrast-based autofocus), you might get away with a linear polariser. They are pretty cheap since nobody uses them anymore, and may have less light loss since they don't need a quarterwave plane like a CFP.

cheddarman said:

Would you believe I went to bed last night thinking that this was exactly what I'm going to do today - start all over!

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Ha, great minds think alike! And we will the ignore the add-on "fools seldom differ" because that clearly does not apply to us!

Yeah, right, if only....

Had a not bad day out today, getting better but it is very dark here at the moment, haven't seen sun for weeks!! However ......................

The little white Egret was quite a long way away so surprised and pleased that it came out fairly sharp. The Buzzard surprised me! Due to the very poor light this afternoon I thought I'd force the shutter up so set ISO to 800. At time of shooting I thought this was a Raven, large black bird, and it was only when I got home that I saw it to be a Buzzard!

Those photos are good but could be better. I see a fair amount noise because of the ISO 800 setting. Because I believe 1/2500 is overkill I would try 1/1250 and ISO400 while keeping all the other settings the same.

Cheers Tom, next time out!! Still experrimating all the time but getting close

cheddarman said:

Had a not bad day out today, getting better but it is very dark here at the moment, haven't seen sun for weeks!! However ......................

The little white Egret was quite a long way away so surprised and pleased that it came out fairly sharp. The Buzzard surprised me! Due to the very poor light this afternoon I thought I'd force the shutter up so set ISO to 800. At time of shooting I thought this was a Raven, large black bird, and it was only when I got home that I saw it to be a Buzzard!

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At 1/3200sec, the speed does not require high ISO and at +0.7EV and a rather uniform background, blown highlight protection does not require a significantly raised ISO either. You could probably have easily pushed to +1.7EV while keeping ISO at 400 instead of 800, making for 1/800s. If that's too slow, nudging the ISO to 600 might have done the trick.

One problem when you are working with JPEG as opposed to raw is that the camera may take high ISO as license for overdoing noise reduction. I am afraid that my treatise of "+EV and raised ISO make for the same result as doing +EV in post processing" forgot about that detail. While the equivalence still holds for the raw image data, at least your buzzard seems to suffer from noise reduction a bit too strongly for best results: the direction of the plumage gets lost a bit. If you are doing raw processing either way, the results of combining +EV and higher ISO will at least be better for chimping (so that you don't confuse buzzards with ravens).

Because I believe 1/2500 is overkill .tom i agree with you that speed is for faster birds

on clear days

A properly adjusted filter does a very good job of making a blue sky darker, improving contrast between clouds (which don't appreciably respond to the filter) and the blue sky. My error about the correct "sun <-> photographer" angle. NTL empirical results speak for themselves.

For more than most folks want to know about polarized light, follow this link . The part that applies to this discussion is in Fig. 7 showing how unpolarized sunlight, interacting with the atmosphere, does yield polarized light. Spoiler: this discussion also explains why the sky is blue.

--

Lead me not into temptation. I know a shortcut.