topic Re: down-sampling in General Discussion

down-sampling

AaronD — Mon, 29 Aug 2016 21:57:43 GMT

I understand down-sampling a high-resolution image will improve its noise level. What I'm not clear about is whether that's done in-camera by setting your capture size to something less than the maximum - or if you should scale it down in DPP or PS. And also, is there an ideal ratio to scale it to? say 1/2 size?

Thanks!

Re: down-sampling

Waddizzle — Mon, 29 Aug 2016 22:31:06 GMT

"I understand down-sampling a high-resolution image will improve its noise level. "

What's that, down sampling?

If you are referring to reducing the sampling rate [or frequency], or reducing the number of bits of resolution, then doing either one those will only INCREASE noise levels.

Re: down-sampling

AaronD — Mon, 29 Aug 2016 22:47:58 GMT

Reducing resolution - as in re-sampling an image to 50% image size in PS. Or by chossing mRAW or sRAW in-camera instead of full-size RAW.

Re: down-sampling

Waddizzle — Mon, 29 Aug 2016 23:39:37 GMT

Don't take my word for it, I suggest that you test it out for yourself. Take several pictures of the same thing, but at different resolution settings. Use your PC to view the photos at 100% resolution, and decide which ones have the most/least noise.

Re: down-sampling

TTMartin — Tue, 30 Aug 2016 00:47:07 GMT

@AaronD wrote:
I understand down-sampling a high-resolution image will improve its noise level. What I'm not clear about is whether that's done in-camera by setting your capture size to something less than the maximum - or if you should scale it down in DPP or PS. And also, is there an ideal ratio to scale it to? say 1/2 size?

Thanks!

A

It is best to do it in post processing when you output the final JPF. You want the file from the camera to contain the maximum amount of information. For me that means shooting full resolution RAW.

Re: down-sampling

AaronD — Tue, 30 Aug 2016 03:33:54 GMT

Very cool, that sounds right. I wondered if it might be the same gathering a few photo-sites into one. But this sounds better...

Thanks!

Re: down-sampling

AaronD — Tue, 30 Aug 2016 03:36:32 GMT

Yeah, but - reason I'm pondering this is I'm trying to decide between a 5DR and a 5Div. I'd like to just get both, but that would hard to justify to my significant other...

Re: down-sampling

RobertTheFat — Tue, 30 Aug 2016 11:54:29 GMT

@AaronD wrote:
Yeah, but - reason I'm pondering this is I'm trying to decide between a 5DR and a 5Div. I'd like to just get both, but that would hard to justify to my significant other...

A

If you're not sure which camera to buy, get the 5D Mark IV. The 5DS R is a highly specialized camera for a very specific type of use. If it were actually what you need, you would not be in any doubt. And you would probably have already known what down-sampling is.

Re: down-sampling

TTMartin — Tue, 30 Aug 2016 12:12:04 GMT

@AaronD wrote:
Yeah, but - reason I'm pondering this is I'm trying to decide between a 5DR and a 5Div. I'd like to just get both, but that would hard to justify to my significant other...

A

Both are full frame cameras. The 5Ds R has 50 megapixels from 50 million photosites, and the 5Div has 30 megapixels from 60 million photosites (dual pixel sensor). Both should have very similar fine grain noise characteristics.

Re: down-sampling

AaronD — Tue, 30 Aug 2016 14:26:44 GMT

Well now see? I had no idea the 5Ds was a "highly specialized camera". Thank you Bob.