ISO setting poll

Davros (Lauren) · #1 24-09-2009, 10:32 PM

As was mentioned in another post lets see what people are generally using for their ISO settings

jjjnettie (Jeanette) · #2 24-09-2009, 10:39 PM

ISO 800 for me, mostly.
Great avatar Mick. There's a little bit of Sheldon in all of us.

Octane (Humayun) · #3 25-09-2009, 09:01 AM

ISO-400. Anything higher and you're asking for trouble.

Regards,
Humayun

jjjnettie (Jeanette) · #4 25-09-2009, 10:55 AM

Quote:

Originally Posted by Octane

ISO-400. Anything higher and you're asking for trouble.

Regards,
Humayun

Trouble is my middle name Humayun.

Terry B · #5 25-09-2009, 11:40 AM

To add a bit of science to the reason for choosing a particulat ISO see
http://www.clarkvision.com/astro/can...gnal-to-noise/

rogerg (Roger) · #6 25-09-2009, 11:51 AM

Quote:

Originally Posted by Terry B

To add a bit of science to the reason for choosing a particulat ISO see
http://www.clarkvision.com/astro/can...gnal-to-noise/

Interesting. Shame it's with such an old camera. It would be interesting to see for one of the new line of cameras (5D/50D/500D).

Roger.

leon · #7 25-09-2009, 03:34 PM

I never shoot any higher than 400 ISO, maybe on the rare occasion it could be 500, but this is not often.

Leon

Paul Haese · #8 26-09-2009, 02:57 PM

ISO 800 and I stand by it. I have seen plenty of good images taken with this level of sensitivity.

avandonk · #9 26-09-2009, 09:00 PM

Read noise is far less at 1600 ISO than at lower for a twelve bit DSLR. If you want to map very faint stuff to your available dynamic range then use 1600 ISO.

You will lose dynamic range at high ISO settings. Bright stars will saturate but at least you have the faint data.

If you need a high dynamic range then 400 ISO is a good compromise.

That is why I am working on my HDR process.

There is no correct answer it all depends on the objects dynamic range and your optical train including camera.

All data for this image was taken at 1600 ISO. 11MB

http://d1355990.i49.quadrahosting.co...MCmosenhc2.jpg

See here

http://www.iceinspace.com.au/forum/s...ad.php?t=50390

Bert

dugnsuz (Doug) · #10 28-09-2009, 01:19 PM

iso1600 subs and lots of 'em.
I like to push for as much as I can get from the DSLR.
iso1600 seems to work pretty well on the 40D in my location - temperatures usually drop sharply at night in my neck of the woods so that's significant too.
1600 in summer is a P.I.T.A!!
No hard and fast as the replies indicate - experiment!
Doug

White Rabbit · #11 28-09-2009, 04:59 PM

800 for me, when time is in short supply you need to catch as many photons as you can. I'd go 1600, buy on a 1000D it looks pretty bad.

Garyh · #12 16-12-2009, 07:31 PM

I like anything from 400 to 1600. Depends on the target. Bright nebs I use 400 and fainter objects I go higher to 800 or 1600 if it`s a cool night.
I have tried a comparison and all the images once stacked for the same period of time (say a hours worth) look pretty similar.

RobF (Rob) · #13 16-12-2009, 08:57 PM

800 most of the time - 1600 rarely a goer at Qld temps. 400 if imaging an object with wide dynamic range (e.g Veil nebula has a bright star in the middle of it) or have the luxury of going for >1.5hrs worth of data.

Geoff45 (Geoff) · #14 17-12-2009, 02:09 PM

Quote:

Originally Posted by White Rabbit

800 for me, when time is in short supply you need to catch as many photons as you can. I'd go 1600, buy on a 1000D it looks pretty bad.

The number of photons caught has nothing to do with the ISO setting. Photons hit the telescope objective and are reflected onto the sensor. Changing the ISO can't generate any more. If you expose at 400 ISO for 10 min or 800 ISO for 10 min, you collect exactly the same number of photons.

Geoff

Geoff45 (Geoff) · #15 17-12-2009, 02:11 PM

Quote:

Originally Posted by Garyh

I like anything from 400 to 1600. Depends on the target. Bright nebs I use 400 and fainter objects I go higher to 800 or 1600 if it`s a cool night.
I have tried a comparison and all the images once stacked for the same period of time (say a hours worth) look pretty similar.

Very true. As long as you taking RAW and are not saturating pixels ISO is almost irrelevant.
Geoff

Octane (Humayun) · #16 17-12-2009, 06:24 PM

ISO is relevant, though.

The higher the ISO, the more noise in your final image.

Stick with a lower ISO for a clean and (quite possibly) noise free image.

Regards,
Humayun

telecasterguru (Frank) · #17 19-12-2009, 11:02 AM

What about ISO setings when using filters e.g. Ha. Do you need to bump the iso up and use longer exposures?

Frank

jjjnettie (Jeanette) · #18 21-12-2009, 11:24 PM

In the near 3 months since this poll was posted I've taken on board what's been said.
I will only shoot in ISO 400 now.
The difference is incredible.

Octane (Humayun) · #19 21-12-2009, 11:55 PM

Thank you for vindicating me, Jeanette.

Regards,
Humayun

jjjnettie (Jeanette) · #20 22-12-2009, 12:13 AM

The lure of more instant gratification when you use high iso's though is hard to resist.