First Clear night in ages...and school boy error made...

[Digz]

How annoying.

Last night was the first clear night for what seems like an eternity. It was quite bluster where I am so I decided to try some widefield AP on my home made rig:

http://stargazerslounge.com/diy-astronomer/140905-widefield-rig-mk-ii.html

The rig itself was great, easy to balance and set up. The annoying part was that I spent over an hour trying to find M31, but that aside I was also out to try a couple of other things like my newly acquired intervolometer and remote desktop connection to my mac from a netbook (will be the other way around when I get some Atik drivers on the netbook)

Anyway the plan was to set up the intervolometer to take 9 or so 10min shots one after the other with a gap in between, guide the setup and monitor from the house. This all worked to plan and I was chuffed at that. Now here comes the school boy error - my camera was set to ISO100 - doh :iamwithstupid:

So I have, what appears to be, 9 fairly decent looking subs but they are all at ISO100 so are probably lacking the detail I was hoping for. Im annoyed that after the first 10min trial sub I didnt realise that the shot lacked its usualy orange glow because of the low ISO setting.

Still, this got me thinking - I shot everythin in RAW which I know will give me about 4 stops of latitude and I wonder is I could process the RAW files into a Tiff before putting through DSS? Has anyone done this and was it any good? I know Im probably clutching at straws because the data isnt probably going to be there in the first place but I was soooo looking forward to improving on my M31 of last year.

Any thoughts are most appreciated.

[bamus]

I think that ISO setting will not change amount of signal received. It will be same no matter if its 100, 800 or 1600 (at least this is theory).

Recently I have changed my ISO 800 to 400 in order to reduce noise and I haven’t noticed any signal lose. My next step is to go down to ISO 200.

It would be interesting if you could show us results after stacking ISO 100 subs. I guess with proper post processing final results will be same as the one with higher ISO, or even better due to lower noise.

[Digz]

Hi Bamus,

What you say is very interesting - I dont know if I fully understand how it works, but if its right I feel a bit better about the mistake.

I will be sure to post my results when I have had a chance to process them at the weekend.

[bamus]

have a look here:

http://stargazerslounge.com/imaging-discussion/87319-what-iso-3.html

very interesting discusion

[focaldepth]

I don't know which camera you have but it is normal to put RAW files straight into DSS.

I think it supports most common RAW formats. You need evry bit of resolution you can get.

[Digz]

Bamus - Ill take a look at that later, cheers.

focaldepth - I do normally put my RAW files straight into DSS, but I was wondering whether I can process the RAWs outside DSS to get the most out of them or whether DSS would do this for me? I guess a bit of trial and error to see.