Filter useage?

[drevilsmom]

I think there needs to be a thread on filter useage, including wavelengths, what they are useful for, etc.... That said :D, I do have a question. I do not need a filter for LP. After all, I do live in an area that is a Bortle Class 2, :lol:. However, I would like a filter that will help bring out some of the nebula that can be seen. I know, I know.... with that good of seeing, I shouldn't need one, but... I don't plan on modding the camera, and would like as much help as I can get. Also, can any of these filters be used while imaging in a prime position, and while using the scope in strictly a visual sense, or will I have to buy two? From what little I've been able to glean, I would need different filters depending on which nebula I want to look at, but a list of which ones get enhanced by which filters would be great. I asked this same question on CloudyNights, and got some great answers, but I felt it would be good to get some input on here as well. Plus, it might help someone else out as well! As an afterthought... I'm guessing I'm going to need to spring for a OIII filter or the like.

PS: While I realize that much of what some DSOs emit is IR, would it still help to remove my UV filter to help on that end of the spectrum?

[Jaxdialation]

Hands down the Ha filter will get you the most bang for the buck.

I do tri-band narrowband imaging with a CCD and OIII and SII are typically 1/2 or less the strength of Ha. OIII is also subject to issues during a full moon.

I can't help you on the UV filter part of your question.

[Adrena1in]

I'll be interested in peoples' replies too, because the whole issue of filters bewilders me as well. So many to choose from for certain targets. All I've ever used is an Astronomik CLS LP filter that clips into the camera, so can be used with scope and EF lenses. Not only cuts out the LP a fair bit, but also seems to bring out the red in certain nebulae.

[spit]

im sure you got some excellant advice at CN, adding to what jax and adr already mentioned here, a simple skyglow filter will give uou extended exposure time- but without modding the camera- dont expect a great deal of nebula response

[drevilsmom]

spit, that is what I kind of figured. But with such little LP, I am not sure that would be much help either. I also found out that since my scope is pretty small (an AT102ED), filter useage is not recommended. Most responses suggested I would need an 8-10" before a filter makes a large difference.

[spit]

i think your confusing using a filter with the advantages of large aperature scope for observing?- while aperature is still important for imaging, theres more factors involved, some of the finest images were made with small APO's, i mostly use a 66mm ED myself for DSO (wide field nebula)- without a filter i couldnt get the exposure needed without reaching the slyglow limit to soon, a filter would greatly assist your nebular shots- i realize the Ha would be 'weak'- but you could enchance that if you use photoshop, with a simple to use but powerful program of atn's- http://actions.home.att.net/Astronomy_Tools.html

[Jaxdialation]

A 102mm scope is fine for imaging. You could use it for a lifetime.
There is a pretty friendly narrow band imaging forum on yahoo. there is also a pretty bad one. Look for the one that Neil Fleming Moderates. There might be an answer there. When I used DSLR for astro imaging, I had it modified by this guy http://www.hapg.org/camera%20mods.htm

I did not do terrestrial photography with the camera, but every indication is that WB becomes an issue which can be overcome by using a custom WB setting.

Nebula are spectacular eye candy, and scientifically interesting. Don't let a few apparent obstacles knock you down. Keep asking questions, it is well worth the trouble. The Astroimaging community is one of the most helpful bunch of folks you could ever meet. Its not unusual for living legends of the craft to answer questions of newbs.

spit, that is what I kind of figured. But with such little LP, I am not sure that would be much help either. I also found out that since my scope is pretty small (an AT102ED), filter useage is not recommended. Most responses suggested I would need an 8-10" before a filter makes a large difference.

[DSLR AstroMod]

Unless you're camera is modded, you're not going to get anywhere enough Ha signal hitting your sesnor. By removing the IR/UV cut filter you now allow 98% of light at Ha wavelengths through instead of < 25% with an unmodded camera. You exposure times will also be dramatically reduced.

HTH

[drevilsmom]

So my question is.... If I remove the IR/UV filter (well, I won't do it, but would probably have it sent in) is that really going to affect my WB? Should it be replaced with a clear piece of glass? I ask these hypothetically for the moment, because I really want to see what my camera can do on my mount before I consider it.

[spit]

i assume the best choice is the baader mod uv/ir filter installed, that is unless you do ir photography- for day use you set a CWB or use the x-nite CC1 filter, youll need step rings with the xnite if you use various lenses- either one will have a slight color shift, but managable, i suggest getting the mount 1st and see how using a DSLR works out for AP for you before you do a camera mod, then youll know whether you want to pursue this any further or not

[Nighthound]

Elizabeth, modifying your camera for astro advantages will require a means to correct that alteration's effects when using it in daylight. This is exactly why I chose not to modify my DSLRs. I don't regret it at all, I'm perfectly satisfied with the images I've taken using my unmodified cameras. See my gallery below. You're very wise to test your stock camera with your existing gear before making a decision to modify. Certainly modifying would help but it can be done at any point once you've tested the waters more.

The only filtration I use is a Hutech LPS-P2, light pollution filter that threads onto my focal reducer/field flattener. It's designed for photography(not all LP filters are) and not only reduces unwanted light significantly, it also makes color balance a lot easier when processing.