RGB Filter Combos???

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Hello All! I am new her to the forums and this budding astrophotog is looking for a little help. I have a 4.5" reflector with an f/8.8 ratio

I recently purchased a basic set of color filters and have been searching high and low for a published chart of what may come from the various combinations you can make for stacking. I’m just starting out with the photography thing and am learning something new each night. I use my webcam in two ways; without the lens over the sensor and directly in the focuser and sometimes I pop the lens back on and attach the cam directly to my eyepieces. I find this works very well for imaging DSO's giving my current set up. I need to get a reducer to have better luck with directly putting it in the focuser. Realizing now that this hobby is a spendy one, i am trying to do as much poor man DIY as I can. So I do realize I already have limitations but I am ok with them for now. It’s great learning for when I can purchase nicer stuff.

Sooo..... My question is does anyone know either from a published source or your own personal trials of a good filter combinations, if there are any, for the various things in the night sky. Specifically the basic RGB filters I have now: #12 Yellow, #58 Green, #25A red and a #80A Blue. Right now due to my location (North Carolina) and the fishbowl of pine trees I live under, i get good looks at Jupiter all night and Anything in or around Cassiopeia and below (below meaning along that line of the milky way under cassi as she climbs higher in my sky throughout the night. My three current obsessions are the Double Clusters, Andromeda and the very pleasing to the eye Pleiades.

I love picking the brain of those in the know so any help or tips or suggestions are greatly accepted. Thanks in advance! Happy hunting!


Hi there, welcome aboard!

What you'll want to do is look up the objects you're interested in and figure out what bands they're active on. Then look at what bands your filters pass. Or if you're trying to peer into the heart of something surrounded by glowing dust, you may block that band so you can see the light beyond it.

Outside of that - it's just playing with an unknown DSO (Deep Space Object) to see what gives you the best images, whether it be just one filter, or stacking - physical or in software over multiple images.

Clear Skies!


Hi Presto, welcome on SDC!

Unfortunately, this is not a 'real' astronomer's forum, you will get more answers from a dedicated place. However, some of us here can help you, like adrenalynn ;)

The biggest problem you have now is the small size and high f/ ratio of your telescope. Any additional filtering will only reduce the available light. Your 4.5" is OK for imaging Jupiter, the Moon, the Sun and maybe Mars. Decent for visual observing, close to useless for pictures :(
I am very, very surprised you can picture DSO's with your setup, unless you have a webcam that is modified to do long exposure shots. But then you would also have to have an incredibly good mount to stabilize a 100cm focal for several minutes. :?

About the filters: on Jupiter you could try the blue 80A to increase the contrast on the red band, but I doubt it will have a spectacular effect.
For DSO's, especially nebulas, the UHC-S from Baader is a top-seller, but close to 100$ it is already a good part of the price of a larger scope, AND it will absorb a lot of light...
Personally, I would play some time with the scope 'as is' and spare for a larger one. For about $500 you can find an excellent 200/1000 (8") SkyWatcher on EQ5 mount, second hand. The difference on the DSO's is huge and the f/4 ratio is also perfect for astrophotography.

Meanwhile, if you have a DSLR you can put it on top of your mount to take large field pictures of the sky. See the kind of results you can have here (starring the Double Cluster as well ;) ): viewtopic.php?f=16&t=23777&start=20
Don't hesitate to add some of your pictures to this thread :cool:

Here is some additional info on filters:
in English: http://sciastro.net/members/portia.php/ ... of-filters
the same in French: http://www.webastro.net/forum/showthread.php?t=67501
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