What's the downside to 25600?

Aside from the noise, is there any downside to setting your max !SO t0 25600?

To Len Philpot, I notice from your gear list that you are shooting a T8i.

So am I. Is there anything I should know about in setting a max ISO of 25600?

My T8i handles 12800 exceedingly well, I think. I wonder how it would handle twice that amount. Any degradation that you know about?

Steve Thomas

stevet1 wrote:

Aside from the noise, is there any downside to setting your max !SO t0 25600?

To Len Philpot, I notice from your gear list that you are shooting a T8i.

So am I. Is there anything I should know about in setting a max ISO of 25600?

My T8i handles 12800 exceedingly well, I think. I wonder how it would handle twice that amount. Any degradation that you know about?

Steve Thomas

Steve, another downside is decreased dynamic range: low ISOs have the best dynamic range.

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I can't help with your specific camera (t8i) questions.

My 7D only goes up to ISO 12800, and that's pretty terrible. But, your t8i is bound to be worlds better IQ wise - it's 10 years younger! 

Dunlin wrote:

Steve, another downside is decreased dynamic range: low ISOs have the best dynamic range.

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I can't help with your specific camera (t8i) questions.

My 7D only goes up to ISO 12800, and that's pretty terrible. But, your t8i is bound to be worlds better IQ wise - it's 10 years younger!

Dunlin,

Thanks. You got me to reading up on Dynamic Range, and I think I understand a little better now..

Just as an experiment, I took two shots of an overhead fan in very dim light with no flash from about five feet away.

The picture on the left was taken at ISO 25600, and the one on the right at ISO 12800. They were taken in aperture priority.

At 25600, the camera was flooded with light sensitivity (or however you choose to define ISO), so the camera set ss speed at 1/10th. The highlights were slightly more blown out and detail was lost in the shadows and darker wood blades.

When I lowered the ISO max to 12800, the camera dropped shutter speed three stops to 1/5th to allow for more light. More detail was revealed in the darker wood of the fan blades. You have to more aware of camera shake at the slower shutter speeds.

If you blow it up to original size, the difference is a little more apparent.

I think I'll keep my ISO max at 12800. My T8i seems to handle that pretty well, I think.

Steve Thomas

stevet1 wrote:

Aside from the noise, is there any downside to setting your max !SO t0 25600?

To Len Philpot, I notice from your gear list that you are shooting a T8i.

So am I. Is there anything I should know about in setting a max ISO of 25600?

My T8i handles 12800 exceedingly well, I think. I wonder how it would handle twice that amount. Any degradation that you know about?

Steve Thomas

To be honest, I almost never shoot in super-high ISO situations. I don't like the noise I see at 400, much less any higher. The T8i seems to do a decent job re: noise (light-years better than my ancient Rebel XT) but it's about average I guess compared to other modern cameras.

What are you shooting that requires such a high ISO?

Len Philpot wrote:

To be honest, I almost never shoot in super-high ISO situations. I don't like the noise I see at 400, much less any higher. The T8i seems to do a decent job re: noise (light-years better than my ancient Rebel XT) but it's about average I guess compared to other modern cameras.

What are you shooting that requires such a high ISO?

Len,

I use auto ISO because I'm not near smart enough or talented enough to even hazard a guess where my ISO should be.

Generally, I shoot in aperture priority with still subjects, and shutter priority with moving subjects and let the camera decide what my ISO should be. I'm not talented enough to be shooting in manual yet. Maybe I'll try a fixed aperture and a fixed ISO, and let the camera work out the shutter speed, and if it gets too low, I'll increase the ISO.

Here;s one I took indoors and the camera selected an ISO of 12800.

There was a fair amount of light on the subject.

I thought it did pretty well.

Steve Thomas

Steve, if you really want to test your camera's dynamic range, try shooting a sunset with some foreground in the shot. Then it would really show.

Like this

I imagine your t8i would handle this scene a lot better in terms of dynamic range.

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Photons to Photos has a dynamic range chart where you can compare different cameras (I don't think the 8ti is on there).

https://photonstophotos.net/Charts/PDR.htm