ISO Question

[Terri French]

I learned something new today. I didn't know that higher ISO settings reduced the dynamic range. Seems like that is something I should have found out a long time ago......better late than never.

 

[Pa]

I learned something new today. I didn't know that higher ISO settings reduced the dynamic range. Seems like that is something I should have found out a long time ago......better late than never.

A pretty good rule of thumb is that you lose one stop of dynamic range with every doubling of iso.

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[John Cichoski]

I learned something new today. I didn't know that higher ISO settings reduced the dynamic range. Seems like that is something I should have found out a long time ago......better late than never.

I didn't know this either.

 

[Terri French]

A pretty good rule of thumb is that you lose one stop of dynamic range with every doubling of iso.

View attachment 1654103

This is good to know!! In a high dynamic range situation I'll be more careful about my auto ISO.

 

[Terri French]

I didn't know this either.

So now we know!! Glad I wasn't the only one.....

 

[JLH]

Many have given such great advice. I will repeat however, BRACKET those shots, the camera will do it for you if you set it up. Keep the ISO lower. Camera makers brag about their high ISO numbers but lower ISO's will give you better pictures as has been pointed out repeatedly.
The D750 has two car slots. Set it up for JPEG on one, RAW on the other, its the only way I ever shoot. Also, don't compress the JPEGS too much , give yourself all the information you can put in those files so you have more to work with later. Stop down that lens a bit!
Don't forget on your D750 you have several choices on how the camera records the data. Things like "Standard, Vivid, Flat, Portrait," etc. Using your NEF (RAW) files you can use your Nikon software to go back to those photos and change this and much more in post processing. Don't overlook the value of post processing. Its just as, if not more, important than the settings you have in your camera.
Take that D750 out and experiment. Try all the different settings before you need them! Play with the software and learn what you can improve and change. When you catch that great shot its too late to take an hour to set up. Besides, its a great and rewarding hobby and playing with the gear and the photos is a great way to have hours of fun.

 

[Replytoken]

Given the D750's sensor is supposed to be highly ISO invariant, I tend to raise ISO as a last resort. And, in theory, you should be better off shooting a slightly underexposed raw image when light challenged, and then adjusting the exposure in post processing as this should give you back a bit of dynamic range. This does run a bit counter to ETTR, where you are trying to capture as much data as possible, but I tend to think that ETTR is better suited to well exposed images. Of course, settings are always situation dependent and YMMV.

--Ken

 

[Randy]

Given the D750's sensor is supposed to be highly ISO invariant, I tend to raise ISO as a last resort. And, in theory, you should be better off shooting a slightly underexposed raw image when light challenged, and then adjusting the exposure in post processing as this should give you back a bit of dynamic range.

your 1st sentence sounds like a contradiction ?
for me never ever underexpose on purpose, I used to do it for high school football but soon discovered what was waiting in the shadows under the helmets.

 

[Replytoken]

Given the D750's sensor is supposed to be highly ISO invariant, I tend to raise ISO as a last resort. And, in theory, you should be better off shooting a slightly underexposed raw image when light challenged, and then adjusting the exposure in post processing as this should give you back a bit of dynamic range.

your 1st sentence sounds like a contradiction ?
for me never ever underexpose on purpose, I used to do it for high school football but soon discovered what was waiting in the shadows under the helmets.

I would never underexpose on purpose (although there was an article about Steve McCurry using that for some effect). If at all possible, I tend to favor ETTR (without blowing our highlights) so there is as much data as possible to work with. But, when you cannot achieve a correct exposure with the sensor at base ISO, there are two options I was referring to in my post above.

The first is to raise the ISO to the needed level. This has the effect of reducing dynamic range, but giving you a proper exposure out of camera.

The second is to not raise the ISO, assuming that the needed amount of light above the base is less than 3-5 stops (as this is usually the most one can effectively pull in post processing). This will give you an underexposed shot, but one with a bit more dynamic range. The exposure of the image can then be adjusted in post processing. The theory is that with an invariant sensor, doing the exposure adjustment in post is no different that doing it in camera, except that you pick up some dynamic range, but at the possible expense of some additional shadow noise.

I admit that I have not tried any controlled experiments to compare the two techniques, but I have seen several articles/posts that did so and found that with good technique, Lightroom could give you back those few stops of light with no loss of IQ. At this time, I do not advocate one method over the other, but bring them up since adjusting exposure in post processing is an alternative way of addressing the issue.

--Ken

 

[Replytoken]

I used to do it for high school football but soon discovered what was waiting in the shadows under the helmets.

I had the same issue when shooting college football night games with my D300 years ago. I fought for every stop of light I could get, and still came up short on a number of shots. And you are correct, the shadows often were not pretty. And if you really want to see dark shadows, try roller derby!

--Ken

 

[hotrod4x5]

So many great responses, I'll just add this: always use the lowest iso possible for your shooting conditions.

 

[Palouse]

So many great responses, I'll just add this: always use the lowest iso possible for your shooting conditions.

This illustrates that very well: https://photographylife.com/news/shutter-speed-aperture-iso-system-video

 

[camerapapi]

Unless absolutely necessary you do not want to shoot landscapes at ISO 1600. Use a tripod and try base ISO. I am not familiar with the Nikon D750 so I will not make any further comments on the camera.
Digital is totally different to color negative film. Exposing for an important highlight is the best way to achieve a good exposure and there is always the histogram to tell us if the bright areas have been clipped. Once those highlights are clipped (overexposed) it is very difficult to bring them back.
I like this image although I am not a fan of electric poles and wires in landscape photography. It could have been interesting to see the foreground but perhaps you intended to have it underexposed with a purpose. I usually do that with my sunrises and sunsets.