Image filters. Lots of questions

[BlackWidow]

Have been using a QHY8 colour and want to get some variation in my images. Also would like to assist with light pollution and star flair..

At first I was thinking of getting an O111 filter and a hydrogen Alpha filter and combining my lights with images using these filters. I also like some of the Hydrogen Alpha B&W shots also. I understand that having a colour CCD will require longer exposure times.

However I have also been told that great improvements can be made to single images of Nebula's using a single filter like the Astronomik UHC. I wanted to know others thoughts to assist me with my choice.

Also I understand that the Astronomik filters have a great name, but what are the diff say between that and the Baader UHC-s filter. There is a vast diff in the price and have found with other filters that some of the lesser brands perform as well, and sometimes better. :shrug:

Regards
Mardy

[BlackWidow]

Is thier no image masters out their that are able to assist? Where is that Paul winner of many awards guy ;). Don't allow me to waste my money on the wrong stuff. I have done lots of that and am really good at it LOL

Mardy

[Poita]

What is the speed of your scope? You will need a very fast scope to get reasonable acquisition times with say a 3nm Ha filter in place, otherwise your exposure times will actually be astronomical.

You would want at least a 7nm Ha filter, spring for a 3nm if you can afford it.
Here are some examples with a QHY8 with and without using a 7nm Ha filter

With:
http://bp1.blogger.com/_9HcYqbvUc4s/R_zzhzuwIuI/AAAAAAAAA8Y/YCopaWfTNmg/s1600-h/M82.jpg

Without:
http://bp2.blogger.com/_9HcYqbvUc4s/R6F5WIYfDYI/AAAAAAAAAXc/-4QC-o6VMBM/s1600-h/color+scaled.jpg

Be aware that your subs times can get up over 20 minutes with the filter on, your mount and guiding has to be up to it otherwise you may be wasting your money. You need to go 2" which adds to the cost.

[BlackWidow]

Hi Peter.. I am currently running at about F6. This is the sort of info I need as it may work out that a UHC filter is a better option and will allow me to assist with light pollution.. I like the idea of seperate filters as it will give me more options I think. But I need to know if those options are realistic on my scope with a colour CCD.



Regards
Martin

[Poita]

I'd borrow a UHC filter and see how you go.
I never had much of an issue with light pollution and the QHY8, even though I took pictures in very light polluted skies. I tried a UHC-S filter, but ended up reselling it.
Someone here will probably lend you one if you post a request in a new thread. I would definitely try before you buy if possible.

I have a 1.25" OIII filter if you want to try it. You would get vignetting but could see how it works conceptually I guess to see what it does for your light pollution issues.