Posts Made By: Greg Bradley

Fantastic Jim. Your images just get better and better.

Greg.

Same to you Ivan. You're a good guy.

Greg.

Ooh, I love it.

Greg.

That is a nice shot. I agree it is a tough target.

Greg.

Hear, hear Steven!! I totally agree. I messed up a drift alignment at a dark site last week that ruined an evening of perfect conditions for imaging - totally clear, totally dark rural skies, excellent seeing. I spent a later niht studying exactly where the south Celestial Pole is in relation to other easily spotted stars.

That way I can get a quick alignment that enables a fine tune.

Another idea I had was to spend some time getting a superb drift alignment. Then attaching a laser to the mount.

Then I adjust the laser to land on the pole.

Next time I can simply turn on the laser and adjust it very quickly.

Greg.

Oh, wow, you must have been happy with that one!

Greg.

Very very nice.

One question. I see some blue halos around the stars. I get the same with my FS152. I was not sure if it was the scope or the camera. I then shot the same target with my RCOS 12.5 inch same camera. Sharp stars with no blue halo. Is this the point where refractors start to lose ground to RC style scopes or is the another explanation? What I did was hardly a scientific comparison.

Cheers,

Greg.

That is the best horsehead shot I have ever seen. Magnificent.

Greg

Very nice Jim.

Greg.

Your focus problem may be you need a focal reducer or an extension piece for your scope. A barlow would be undesirable as it lengthens the focal ratio and generally you want that shorted and flatter for imaging. Such as the wonderful Televue .8X flattener/reducer for different focal length scopes.

For example I use a Nikon D70 on a Tak FS152 or a William Optics 80mm or an RCOS 12.5 inch.

The FS152 has 2 configurations; 1 with an F6 focal reducer where the camera fit snugly behind it with no need of extension tubes.
1 without the reducer which requires an extension tube to come to focus.

The William Optics fits the camera with a TV reducer/flattener fitted to it without extenders. Without the reducer it still comes to focus but I think it is more in-focus from memory.

You need ScopeStuff part TA2P which is a 2 inch barrel that screws into a T Thread adapter screwed onto your Nikon D70s. If you need in-focus then the reducer/flattener is the way to go I am pretty sure.

I could check what effect with and without Televue .8X reducer/flattener makes as far as focus goes if you are interested to be sure.

Some use a Celestron or Meade F6.3 reducer on the TA2P and I have as well but the Televue unit is far superior even if it reduces less than the other.

As far as focusing goes, use Nikon Capture and use a laptop or computer. You control the camera from the computer and the images are downloaded and displayed and you can view the images at a larger size by adjusting the software. This way you can frame your shot and get the focus just right before imaging. You can also batch time lapse photos to take a series of up to 60 second shots using that software. Images Plus is the standard for image stacking and RAW file conversion software. It also can control the 70s like Nikon Capture but with a Hap Griffin infrared remote you can program a series of shots of any length and ISO setting. It has a focus aid as well. Also the images are saved in your hard disk and this saves the additional step of downloading shots from your camera to your computer later. It does however require a computer. Otherwise slew to a bright star and focus through the viewfinder and take an image and blow it up using the magnify function on the D70s display (see your manual about which buttons to push). I find I can normally get a sharp focus simply looking through the viewfinder (make sure the little slider next to it is set for your vision as it can move when travelling!). Just use a bright star and focus it.

Greg.