Anyone Tried Dual ISO with an Infrared Camera?

Started by russellsnr, July 20, 2016, 01:00:41 PM

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russellsnr

Hi, Just asking here as waiting for a converted camera to reach me.
Wondered if anyone had tried Infrared photography with the dual ISO option and results/views if any?
Thanks
Russ

garry23

Yes, with my ISO converted 50D.

I found it was not worth it.

That is I ETTR and find 'all' captures are handled without Dual-ISO or bracketing.

The IR captured spectrum, ie I use a 720 edge, means I can handle it all 'normally.

Cheers

Garry

russellsnr

Hi, Thanks for that, answers my question.
Russ

a1ex

If you ever find a contrasty scene that would require bracketing, you could try dual ISO as well. I have one such file in my test suite, taken with an IR filter on a regular camera, so the converter should work just fine.

Most of the time, I trust Auto ETTR to decide whether Dual ISO is needed or not.

garry23

Just to complete my experience. I have shot at mid day, in the middle of summer in Utah and New Mexico. Lots of contrast ;)

I found the shutter didn't vary much, and I didn't need dual or bracketing.

But as A1ex say, if you need dual or bracketing, it all works.

Btw. Difraction corrected depth of field only is set up for vis. You will need to change the frequency in ML code. Or, as I did, write a simple script to calc the CoC equivalent, i.e. fool ML.

Also, I use a 10-20mm lens and  focusing is a non issue, i.e. Hyperfocal.

Cheers

Garry

russellsnr

Hi, again many thanks for the replies.
On the focus side of things even if the camera has been calibrated to adjust with the IR filter do you still need to write or adjust the ML script for coc?
Thanks
Russ

garry23

With a WA lenses and focusing on the far side of the HFD, I don't think there is a worry.

It also all depends on where you are showing your images: web, in a gallery or a print in front of a judge, ie what is your line pair per mm criterion.

Bottom line: I find because you are only capturing the IR frequencies (lenses-systems are designed for vis capture), and if you are using a WA lens, then using an HFD+ approach works out fine. If you do need to 'do more', I personally use my focus stacking script with my IR converted 50D. And as I said before, you can play around with the CoC, eg the 29micron FF ML number is not many line pairs, and you should consider reducing this for exacting print work.