Images through a DSLR

[barn2688]

Hi everyone,

I am new to these forums but I had a couple questions about equipment. I have been doing astrophotography for a little under a year now. Before now, I have used equipment from my school, (I am a sophomore physics and applied mathematics major with an interest in astronomy and astrophysics). I have done some work with a couple of the SBIG line of camera and also some of my professors equipment, a Canon Digital Rebel XTi and a XT. However, both of these camera have been modified to remove the back filter that limits the amount of H-Alpha that the sensor reads. Recently, I have upgraded my personal equipment and have gotten a unmodified Canon XT. I like to do landscape and macro work. I was wondering if there was any way to get the effects of an modded camera while doing astrophotography without actually modding it. I still want my camera to be able to pursure landscape, macro, and other types of camera operations.

Thanks in advance!

[RickJ]

See the Hutech website.
http://www.sciencecenter.net/hutech/canon/index.htm
Rick

[hha1]

Barn2688:

Welcome to Astrophotography. It is a fun hobby, which I started doing from my backyard after working for a decade doing astronomy with a telescope in Earth orbit.

My suggestion is not to modify your XT camera. You can take wonderful photos of the nightsky with it as is, particularly wide field stuff, if you get yourself a prime lens, like the Canon 200 mm f/2.8, which can be used wide open. With big telescopes you can see only a very small field of view. This is like missing the forest because all you can see is pine needles and some neat pine cones on the trees. Look at http://www.bautforum.com/astrophotog...es-2007-a.html
to see what I mean.

hha

[smasraum]

Barn2688,

I have a Rebel XT, and I'm very new to astrophotography myself. I looked through the Hutech site the other day. It looks like you can modify your camera and still take "normal" images with it by using a filter on the end of the lens for the normal images. The biggest deal for me is the cost. I'd really like to see some before and after comparison shots to see how big a difference the mod makes. Hutech has 1 before and after shot, but the shots appear to be at different focal lengths and are for different periods of time. The biggest difference seems to be color (which is one of the neat things about this stuff).

I just haven't seen anything to concretely justify the cost of modding one of these cameras. And based on some of the stuff that I've read, if you want to do really high powered stuff (Deep Sky Objects, I think it's called), webcams seem to be the way to go more than DSLRs. So you could keep your rebel unmodded, use it for wide field, and use the money that you save to get a good webcam for the deep sky stuff.

But, I'm a noob myself, so I'm not sure my advice is worth the normal 2 cents.

Here's similar info from someone that's got more experience than I do. Basically, it addresses the whole DSLR for astrophotography thing (more than the modded DSLR question)
http://www.astropix.com/HTML/I_ASTROP/CAMERAS.HTM

And the main site that it came from
http://www.astropix.com/HTML/I_ASTROP/TOC_AP.HTM

[NGCHunter]

Actually a webcam is best for planetary work. In my experience my DSLR far outclasses my old "glorified webcam" (DSI 1.0) for DSOs. Here's a direct comparison shot of a rebel xt modded and unmodded. It looks like you just need more subexposures to be able to get the same signal on objects whose light is mostly in H-alpha. For anything else, galaxies, reflection nebula, etc, it should be dead even between the two.

http://farm1.static.flickr.com/137/3...cf385086_b.jpg

I use an unmodded XTi now, and though I've literally just started I'm far more satisfied by the quality than I was with my DSI.

[smasraum]

NGCHunter, thanks for the post and comparison shot. It just doesn't seem as if the cost is worth the result unless maybe you are really hardcore which I'm not at this point.

[RickJ]

Do note the exposure times. The unmodified version needed 4 hours of exposure to get a far inferior image to the one hour shot. Nebula shining mostly in H-alpha light will image faintly even if you image all night. The unmodified camera is fine for star clusters and fairly good for galaxies.

Rick

[Tinaa]

Moved to Astronomical Observing, Equipment and Accessories.

Welcome to BAUT barn2688!

[barn2688]

Thanks for all your input. And especially for that direct comparison shot. I think that I am going to stay with an unmodded camera for a while. Try and build up technique by imaging star clusters and galaxies before I have the camera modified (also to save up some money).

Again, thank you all.