First Light Zenith Star 66 Petzval

[bkm2304 (Richard Brown)]

Hello all,

After a long, long wait for the right part I finally hooked the scope up to my eq, found the pole (well close to it!) and started shooting. M42 was the first obvious place to start - although I usually christen my scopes on Alpha centauri which was too low.

Here is the first effort. I took 3 x 30sec images at prime focus of the Petzval with a Nikon 40D. Then stacked them in Registax - but it said the stack was only 2 - so who knows? I am pleased that;

a - I actually captured an image(!)
b - The tracking was pretty Ok

THere is much more to understand about the process, obviously. EG. when I convert my 1mb jpegs to bitmaps so Registax will read them, they blow out to 17mb! Should I collect them as another format from the camera?

Also, how on earth do I get a crisp focus? My camera is on the end of the scope and looking through the view finder renders a very dark field. I'm not sure when focus is best.

As some of you may know it's been a long time since I looked into a refraaa... refraaccc... refraccct... something without a mirror - and it's so SMALL!!!! So please help me if you can!!!

[Dennis]

Welcome to the “dark side” of refractors and astro photography! It can be a roller coaster ride, but gee, its fun!

In terms of focusing, a quick and cheap solution is to use the Hartman Mask. Have a read of this article by 1ponders.

Cheers

Dennis

[Garyh]

Thats a good object for a start!
Get yourself a copy of Deepskystacker..(freeware) You can then shoot in RAW with your Nikon.
Besides what Dennis has mentioned above, you can make yourself up some diffraction spikes with some fishing line or thin wire. Just take test focus shots and check the spikes and refocus until they become one very thin line. Then you have good focus. Like the hartman mask if you are getting away from focus you will have a double spike and the closer you get they merge into each other till it is razor sharp!
cheers Gary

[dannat (Daniel)]

Thats a pretty good shot I think for a first go, albeit a little blue.
Well done
I'm interested to see how you go as when I purchase a dslr I would like to attempt pics with my WO

[bkm2304 (Richard Brown)]

Thanks, lads. I'll get the Deep Sky Stacker and make a diffraction rig to get focus. I must say that the picture side of things is very rewarding - even after a night to actually achieve a result is very encouraging! I actually thought it would be more frustrating to get the whole thing going! I hope they aren't famous last words!!!!!

Richard

[Ric]

Hi Richard, that's a good start, well done. Once you sort out the fine focussing you'll be on your way, a lot of good advice has already been given.

Looking forward to your next images.

Cheers

[leon]

Good first image, Richard, keep at it mate, as it has been said, it is a learning cure, but isn't it fun.

Leon

[Terry B]

Originally Posted by bkm2304

Hello all,

After a long, long wait for the right part I finally hooked the scope up to my eq, found the pole (well close to it!) and started shooting. M42 was the first obvious place to start - although I usually christen my scopes on Alpha centauri which was too low.

Here is the first effort. I took 3 x 30sec images at prime focus of the Petzval with a Nikon 40D. Then stacked them in Registax - but it said the stack was only 2 - so who knows? I am pleased that;

Great start
Registax probably isn't the best to use for deep space.
Deepskystacker is good and free. I use Iris which is very powerful and free also. There are tutorials on the same site.
It's best not saving as jpeg as you can't use dark frames with jpeg. Use the raw file option to save. You end up with very big files.
After preprocessing a series of 9 frames with darks, flats, offsets etc from my canon 40D I had about 2 gig of intermediate files in the recycle bin.
Good luck

[bkm2304 (Richard Brown)]

Two efforts from last night. 7 stacked images @ 30secs each with the 66mm Zenith Start Petzval, and a dark all washed through Deep Sky Stacker. Fiddled with the images in the processing part of DSS.
Compare to image in the first post in this thread. The learning curve is slow but improving. Any comments welcomed!

Richard

[Alchemy (Clive)]

Given any comments are welcome,

great start as terry b said, theres some good advice given there, the longer exposures the more of them the better result you get.

i enjoyed having a look