Can someone recomend me an imager?

[skintigh]

I've been doing some astrophotography off and on for a few years and it's about time I got a real imager. So far I've used a DSLR and a Celestron NexImage. I'd rather not spend too much, like over $400, unless you guys think it's seriously worth increasing my budget.

I love taking pictures of planets, but also some deep sky objects like nebulae and galaxies. I'm guessing most imagers wont be able to do both tiny objects and huge nebulae, is that correct?

So far I found the Meade DSI Pro II with filter set for $320.

Oh, I suppose it would help if I mentioned I had a 12" LX200GPS and live on the outskirts of a city.

[Siguy]

If you already have a DSLR and a Neximage, keep in mind that the DSI II won't give you any better images than you can already get with a DSLR; in fact, the DSLR will probably do better than any sub-$1000 CCD (this is just an assumption, but I have a feeling it's true). I mean, do you know how small and low resolution the chip in the DSI cameras is? It's old tech. However, if you plan on switching to CCD imaging, I bet the DSI would be a great camera to learn with, but it will still be far from the last you'll ever need in that case.

[RickJ]

If you haven't already, replacing the IR filter -- factory ones block H alpha light -- with one that doesn't block H alpha would be a far better way to spend your limited budget. Like Siguy I know of no cooled CCD camera with the FOV of a DSLR. It's the cooling that separates the DSLR from true CCD one shot color cameras. Mono CCD using filters would be yet another step up but that is even more expensive.

I don't do DSLR work but I think there might be better processing software than what you use.

The NexImage is just a repackaged ToUCam. A tried and proven planetary imager. While it has pretty well been replaced by the dmk21au04.as as it takes up to 60 frames per second and better freezes seeing for planetary work. DSLR or deep sky CCD is poor for this purpose. That camera with filters for color work can do some amazing imaging. Still your NexImager isn't all that far behind the curve so I'd stick with it unless theres other factors you haven't mentioned.

Unfortunately the move up to cooled CCD isn't a cheap one if you are looking for better quality than your DSLR gives.

Not mentioned is what you are using to guide the deep sky images? The NexImage? The DSI II might make a better guider but certainly not a better imager.

Rick

[skintigh]

The DSLR is almost impossible to use. I focus randomly, take a picture, view it, zoom way in on it, focus randomly, take a picture, view it, zoom way in on it, and after 10 to 100 attempts it's sorta in focus, at least until I slew the scope. And there is no way to take a picture of a planet with it, it's just a white dot.

The NexImage creates grainy, liney, dim images. It's okay for the Moon or Jupiter as long as you don't try brighten the image, but anything else every other line is much brighter and the image is very orange. Maybe it's defective? And the software is horrible.

I will check out the dmk products.

[Siguy]

I do DSLR imaging, and I have the same focus problems. However, there are some tools that help (magnifying viewfinder, replacing the focus screen.) None of which I've tried myself though.

For the NexImage, how are you taking images? You're not just supposed to take snapshots with webcams, you're supposed to take videos and stack individual frames with programs like Registax.

[RickJ]

Sounds like you have an old DSLR. Today's good imaging ones (most prefer Cannon) connect to a laptop same as a CCD and allow you to focus the same way. Another solution might be the Bahtinov focus mask. It gives a pattern that shows you how far and in which way the image is out of focus. I've never used one as I run remotely so can't put on and take off a focus mask. Those that use it love it. You can make it or buy one for your scope. Either work well. Don't try to focus on the dim object you are photographing. Focus on a 4th or so magnitude star then slew to your target. I used a film SLR for years (like nearly 50) and this worked well for me.

I had a ToUCam which worked very well for planetary imaging until I stepped on it in the dark. That crunching sound was the end of it. I don't know the software Celestron packs with it. Likely third party web cam software could run it. You might check on a web cam forum. I've never gotten back to planetary imaging since that fateful night. The point of a web cam, as Siguy says, is to take 800 or so frames at high speed and stack them using Registax or similar software. I mention Registax as it is free and quite good. Some prefer the pay version of K3CCDTools. I'd start with Registax.

Rick

[skintigh]

I thought about modifying my DLSR, but doubt I will do that. I was considering the new Rebel with live view and HD video, but I read it is far noisier at higher ISOs than Nikon.

I stacked images with the Neximage, but unless I am recording video of something really bright, almost any adjustment to the brightness or gamma causes interlaced lines on the image. Maybe I need to play with it more. Registax did work magic on some Jupiter video.

So I just researched the DMK21AU04.AS, it seems great, but not all that different than the DSI Pro II. The pixels are slightly smaller (5.6x5.6um vs 8.3x8.6um) but other than that they seem extremely similar, except that the DMK is more expensive and requires another $400 in filters and a wheel.

Is there noise issues or something I'm missing? I assume there must be. Also, I seem to have no increased my budget. Anything else I should look at?

Thanks in advance

[RickJ]

The two are VERY different. The DSI Pro II is just what its initials stand for Deep Sky Imager. The DMK is a planetary imager. Two very different tools for very different imaging purposes. Neither does the other's job.

Rick