Getting the best Widefield results form a 350D

Is there any real advantage in removing the IR glass filter
in the Canon 350D for wide field Astrophotography?
And what difference would having or not having a UV filter on the lens make?

The canon dslrs are optimised for normal daylight.
If you remove the internal filter, you let in alot more light in the red end of the spectrum. This lets alot more light onto the chip thus showing more for the same exposure.
In particular, stars emit alot of light at the frequency of H-alpha 656.3nm. The internal IR filter blocks alot of the light at this frequency. Therefore, you get a major increase in the amount of light at the peak frequency at which most stars shine.
www.astrosurf.org/buil/350d/350d.htm

As for UV filter at thefront, I wouldn't use it. Main reason would be internal reflections. On the Moon with even short exposures, it creates a problem. With long exposures on bright stars, I can't see it helping the image.

Frank,

It really depends on what you plan to image and in spite of the fact that it may be widefield (or not). For example, to capture the North American Nebula (NGC 7000) which covers a large amount of space, you need a widefield shot but it is an emission nebula which means "red" ... and which translates to h-alpha sensitivity.

I guess I really need to have that filter removed then.
Either that or head out to the Atacama desert.
I reciently bought my wife a new canon so that is principally our 'regular' camera.
(I'll never forget the night I drove out to our observing site,
zipped open my rucksack only to see a gaping hole where my canon should be!)
Synopsys of phone call.
''hello''
''Hey babe, ahh, just a quick queston.
did you take the Canon tonight?''
''Oh yeah, I brought it into my Nieces birthday party.
why?
You didn't want it tonight did you?''

'' ..............''

''Hello.....''

*Click*

''Babe?...''

*beeep....., beeep...., beeep....., beeep......"

''Hun?''


Anyway..
I'd be very slow to remove this filter myself because
it looks like a very delicate procedure.

I did a quick search on the net and I see a few places offering the service.

There are issues with replacing the filter in it.
The internal IR filter is of a certain refrative index and thickness.
If you replace it with a more transparent filter, you need to know the level of refraction in the filter and the thickness of it. Why? Well, if you get another piece of glass and slap it in, the camera lenses apparently won't come to focus, or so I've heard.
However, if you do know the details of the replacement glass, you can insert spacers (pieces of tin foil) between the edge of the replacement filter and the chip to replicate original filter.
Myself and Dave Grennan did this one day to my 300d and it worked perfectly. And yes, it is a delicate procedure - a bit like open-heart suegery.
Unfortunately, a few months ago, I put in a Canon AC power adapter into my camera it it blew the camera. So, that camera went to the camera museum in the sky.
The "ideal" scenario woud be two cameras - keep the 350d you have and get a second-hand modded DSLR with no internal filter. I recently picked up a second-hand hutech-modified 300d for a very good price. This is for astrophotography and I will use the 400d I picked up second-hand for normal photography.

Frank/Michael,

Baader in Germany will change the filter for you for 75 euro and nothing more. It is a very good deal and a few local friends have used their service.

As for the daylight photos, it is a trivial matter since one only needs to program the white balance setting (the Canon allows for such permanent programming and which can be activated at will).

Also and as Michael mentions, these cameras are readily available on the resale market and at very good pricing. I now have an EOS 300d, a 350D and I will not be surprised if I add yet another digital Rebel.