What to expect with a H-Alpha 35nm CCD filter?

[Alaness]

I've just picked up a h-alpha 35nm filter. I will be using it on an unmodified 550D (T2i). My question is what can I expect to get out of this? I live in a fairly light polluted area so I'm hoping that I'll be able to take much longer exposures of things like nebulae and galaxies without the images bleaching out. But I won't get my hopes up too high yet.

Any input would be very much appreciated.

Cheers,

Alan.

[ollypenrice]

The 35Nm filter is very wide for CCD. Most people use a tighter bandpass, 13Nm or smaller. I don't know how sensitive your unmodded camera will be to Ha so the thing is to try it. How you remove the unused pixels (two greens and a blue per matix component) in software I don't know but it can certainly be done easily since folks do it all the time. Someone will come in with that information, I'm sure.

Once you have the mono Ha image you can either enjoy on its own or blend it with the red channel to enhance emission nebulosity in a colour image.

Olly

[Psychobilly]

I have used one but on a modded 1000D when I fire up the PC later I will dig out links to some pics...

I used it for some mono images and for combining with the OSC data...

Peter...

[Psychobilly]

Sorry took a while to find some sample images...

29x300s Baader BCF Modified 1000D on Megrez 72 with FFIII and 35nm Baader Ha Filter

Here's 6 hrs of the Veil Complex with the same setup...

And combined with OSC data from the Same setup with the Ha filter removed and an IDAS P2 LP filter fitted for the OSC Subs

I found that my un modded 500D was more sensitive to Ha than the un-modded 1000D but moding the camera makes a big difference...

Sorry for the delay in digging out the images...

Peter...