I"m considering getting a high quality 60mm or 90mm apo scope as my very first scope, as I really intend on pursuing some nice astrophotography work.
But after my initial forays into basic DSLR widefield photography, I'm not so sure. I'm already finding the light pollution down here in sunny Melbourne (Mentone area) pretty frustrating. I'm using the excellent Astronomy Tools addin for PS, it removes a fair bit of pollution, but with the LP, there isn't much subtle stellar light coming through.
So guys 'n gals, I'm wondering, would I be wasting my money? Or will a dedicated light collector and mount, combined with a decent filter or 2 give me enough imaging ability to keep me occupied between (rare) dark sky outings?
In my opinion it depends on what standard you are happy with. I have seen some quite good images taken in suburbs with DSLRs. My images are mediocre at best - mainly due to lack of clear skies, LP and relatively short exposures (+ other excuses). But overall I am happy with what I get as long as they give a reasonable resemblance to the object.
I find that the wider the field of view the worse light interference seems to be - especially from nearby lights. (neighbors). I hang a black sheet over a frame to try to cut out some of the direct light.
You won't be wasting your time - but your images will still suffer from LP and even if it can be processed out it obviously won't be as good as a dark site especially if you are trying to capture faint details.
Thanks Tony, yes I suppose we need to be satisfied given the compromises. I'm still getting a buzz out of my basic images, that's the main thing. Not getting too perfectionistic, it'll make you go crazy I feel.
Here's my latest image, about 10 secs with a 50mm on a tripod, 5 shots. Broke my personal best for no. Of stars counted by DSS, 5,700! And I caught a satellite in the images too. So you're right, we can still enjoy.. http://www.flickr.com/photos/4823258...242386/player/
You can use an EOS clip CLS filter or a front mounted Hutech IDAS LPS filter on the DSLR and try and eliminate some of the nasty stuff, but what may help more is a longer focal length refractor (in the F7 or higher range). Wide field F5 refractors will take faster pictures with more coming through but you will also get the light pollution along with it. Just like a higher mag eyepiece reduces the Field of view and then increases the contrast, a longer FL scope will reduce "somewhat" the effects of Light pollution.
So, filters on a fast F5-6 or slower refractor may help, otherwise, you would be looking at imaging in narrowband using a dedicated mono cooled CCD camera and say OIII, SII and Ha filters which completely nix the sludge. This is obviously much more expensive, but may be the only option later on if the DSLR and the LP filters don't remove enough of the nasty stuff for your taste.
My EOS clip does an OK job, so its a relatively easy way to try it out and see what you think. A quality refractor will set you back a bit, but the views will be amazing, visually and photographically and most mounts will carry these with ease.
otherwise, you would be looking at imaging in narrowband using a dedicated mono cooled CCD camera and say OIII, SII and Ha filters which completely nix the sludge. This is obviously much more expensive, but may be the only option later on if the DSLR and the LP filters don't remove enough of the nasty stuff for your taste.
QFT! This is your best option, albeit one that'll result in a big sucking sound as cash flies out your window...
That said, there are some fine images posted on IIS from people who have challenging environments to deal with.
Light pollution is a pain but can be circumvented to some degree, depending on your field of interest. Planet imaging doesn't suffer from it at all. Neither does solar imaging, obviously lol. DSO's suffer from LP more than anything else, some types more than others.
Nebula contain gases of specific wavelengths. For one shot colout, LP filters can help here to pass the wanted light and reject unwanted wavelengths. They come in different strengths from something like a gentle Baader Moon and Skyglow filter, to something more medium like the Astronomik CLS, Baader UHC-S, Lumicon Deep Sky, to a heavy Astronomik UHC. LP filters can have a colour shift and may be tricky to get neutral colour.
After that there's narrow band imaging. Can't be done with an unmodified DSLR. Best done with a dedicated mono CCD camera. Narrow band Ha can even be done in full moonlight. Narrow band filters are expensive. At this stage it will cost a few $$$ to get something decent going but will have the best chance of cutting through LP.
Edit, only took me an hour to type this up so have been beaten in the mean time lol.
You can also use photoshop (or other software) to remove the gradient. This gets harder when there is a lot of nebulosity in the image.
Here is your image with some gradient removal.
You can also use photoshop (or other software) to remove the gradient. This gets harder when there is a lot of nebulosity in the image.
Here is your image with some gradient removal.
And thanks for all the suggestions and encouragement everyone. Well the missus won't thank you! Gawd, I haven't even got my first scope yet and I'm already considering CCDs???? I think I AM going mad.
The SLR filters sound like a good initial option. I should just be patient and wait for the first results. At least you've convinced me to pull the trigger.
Simon, I'm using an f7 102 mm LUNT ED with reasonable success in an LP situation. As Chris says a longer Focal length lets you cut out some of the glow. The rest is plenty of exposures ( more photons please ) and processing skills to seperate the LP form the image. I also use an Astronimik CLS filter in many cases. means more exposures needed but makes processing a lot easier.
The LUNT has quite a long dewsheild which also keeps side glare down and I'm lucky that my backyard and the Ob is well away from streetlights and nearby houses.
Clouds are another matter altogether ....