Some Advice Would be Appreciated - Imaging Jupiter

[jandcando]

I'm having another go at astrophotography, and this time around I discovered the difference between light, dark, flat, and bias images. My camera is a Nikon D50, and I'm attaching it to the eyepiece of my Celestron Powerseeker 127EQ Newtonian using the appropriate T-ring and whatnot. To keep the camera steady, I put it on a time delay for every shot to let the vibrations settle down. I started with taking 20 pictures of Jupiter with 200 ISO and a shutter speed of 1.3. I cannot adjust the focal ratio because the lens of the camera is replaced by the T-ring. This also means I rely on the telescope eyepiece for focusing, which isn't always sufficient. I have left the white balance at the daylight setting. Do I need to worry about that?  All pictures are in .NEF format.

So I took the photos on a pretty warm, humid night (not the best conditions), but I decided to give it a shot anyway. I also noticed that the camera was just a hair shy of being completely focused, even thought the eyepiece focus knob was turned all the way.

I took 20 of each kind of image, following this guide.

The lights looked something like this:

And the flats were taken using a smooth paper towel taped across the front of the telescope. I had a friend shine a white LED flashlight at the towel and captured pictures that look like this:

The guide says to let the camera decide the exposure time to use by using the auto function, but that doesn't work on the D50 without the lens attached, so I just did it manually.

I tried stacking all the frames in DeepSkyStacker, but it wouldn't recognize Jupiter as a star so no stacking happened.

I would appreciate any tips for gear I could use to help make nice images, and also I would like anything wrong with my technique to be pointed out. I currently have a remote control for the D50 coming in the mail, so that will be useful.

[kens]

Many newtonians will not come to a focus with a DSLR due to their longish backfocus (the distance from the face of the mounting surface to the sensor). Yours appears to be one of them. Some people modify their scopes to move the primary closer to the secondary to overcome this.However, this can render the scope unusable for visual.

Planetary imaging is best done with a video camera so you capture hundred if not thousands of subframes. Plus they usually have a shorter backfocus. You then stack the video images with Autostakkert then use Registax for wavelet processing.

[michael.h.f.wilkinson]

Planetary photography is best done in video mode, preferably without compression. The videos are then stacked with AutoStakkert! or Registax. A web-cam or planetary camera is generally better. Registax also lets you stack lists of individual images.

Ideally, you should stack several hundreds of shots out of a video of thousands of frames.

[ronin]

In a way you have done nothing wrong, but just about everything may have to be altered.

Weird world of astro-imaging.

A DSLR as said will usually not get to focus, there is not enough inwards travel, one option is to mover the mirror up the tube so that the focal plane moves out. However I do not think you need to yet. You may later on down the road.

Planets are "generally" imaged with a Mak or SCT, so about 1500mm focal length, guess 2x or 3x what you newtonian delivers.

As also mentioned most stick a webcam in, take a video then stack the movie (,avi) through software like Registax (there is another but I can never recall the name).

In that you identify a good image, tell the software to pick the best (say) 500 that match and then these are stacked and processed.

So:

A Barlow of say 3x will deliver the focal length/image size that is required.

A 3x barlow will also push the image out and so it should hit the DLSR sensor.

You can take movies on a SLR but I think that a webcam may be better (less weight) - your choice.

You "may" want a 5x barlow but at that increase the image quality might suffer.

If you later go DSO imaging then you do not want a barlow, it is prime focus imaging and so the mirror will then need to be moved.

If you go for Jupiter then limit the period of the movie to something like 90 seconds max - Jupiter rotates fast.

So the initial way would seem to be get a good 3x barlow.

Then scratch head.

Best of luck.

[jandcando]

Thank you all for this input! Unfortunately, the D50 does not record video and I'm not really sure if I even have a webcam. I do have a stock 3x barlow lens laying around that I might try using tonight if the weather permits. (I'll get a video camera later down the line)

Thanks for pointing out that focus issue, guys. That explains why my moon shots from last year are blurry...

I'm willing to just invest in a better scope, this one has been a bit of a pain to use anyway. The idea of a computerized telescope that finds stuff for me is kind of repelling to me, though. Is it pretty much standard to use such a scope for astrophotography, or can I do just as well with a manual scope?