ETA, antenae and M20: Prostar 127mm

[allan gould]

I wondered how the new Prostar 127mm scope would go with a Canon 350D unmodded DSLR rather than the Watec camera and how flat the field of view was, so I took it to a dark site and gave it a try. The M20 and Eta Carina shots are a single 5min, iso800 shot, no darks or manipulation and full frame. I was pleased to see a very flat field of view with no vignetting and stars sharp to the edges with minimal colour abberations. The shot of the antenae was 4x5min, average stacked in DSS, stretched in PS to reveal the 'antenae' and cropped to remove amp glow in the bootom RH corner.
Overall I was very pleased with the scopes performance but not mine.
Need to accumulate more shots and go deeper. Most of all I need to improve my focus - doing it by eye through the viewfinder is not the optimum choice.
Regards, Allan

[jase (Jason)]

A nice panel of images from the new scope Allan. The field does appear to look flat. Well done.

[Astrod00d]

Those images look good Allan, thanks for posting them.

The single 5-minute sub of Carina shows good colour, the stars seem free of CA. Field is flatter than an ED80. Perhaps just a little bit of coma in the lower left corner. Were you using a flattener or is this uncorrected prime focus?

Cheers,

Rob

[allan gould]

Originally Posted by Astrod00d

Those images look good Allan, thanks for posting them.

The single 5-minute sub of Carina shows good colour, the stars seem free of CA. Field is flatter than an ED80. Perhaps just a little bit of coma in the lower left corner. Were you using a flattener or is this uncorrected prime focus?

Cheers,

Rob

Rob
The ETA and M20 are single, full frame totally unprocessed shots. No darks subtracted or stretched. The only one I processed was the Antenae shot to bring out the arms. No corrector or reducer used. Straight camera to scope.
As I said I'm pleased with the scope.
Allan

[Alchemy (Clive)]

id love to have a big refractor, particularly a good one

[peter_4059 (Peter)]

Allan,

They have worked out nicely. I like the antanae shot.

I'm goning to wait a couple of days before I process mine - that second night has caught up with me!

Peter

[Ric]

Hi Alan, a lovely selection of images. The Antennae galaxies have come up a treat, the extensions came out great.

Cheers

[Zuts]

Hi,

Looks like you are on a winner with the new scope. A 5 inch refractor is a heap of glass for the money you paid. Can I ask what it is like regards field curvature for visual at low focal lengths?

Paul

[allan gould]

Originally Posted by Zuts

Hi,

Looks like you are on a winner with the new scope. A 5 inch refractor is a heap of glass for the money you paid. Can I ask what it is like regards field curvature for visual at low focal lengths?

Paul

Visually its fine, but it did do one thing in that I realised that I need better eyepieces. Using a friends Vixen LVWs (22 and 13mm) they were what was needed to do justice to my scope. The crappy Meade ones did not cut it as they relied on the f10 of my SCT to be OK but the f7.45 of the scope needs better eyepieces. At low power the scope appears flat across the eyepiece.
But I really must stress that I'm talking about the scope that I have and that there may be variability in their manufacture in China that those that are purchasing directly are taking a chance (in my opinion). I purchased mine from Steve Massey and I trusted his detailed description before purchase in the understanding that if it was not an APO and as described it would go back. Thats what I paid for and I was glad to trust him and his opinions. I sincerely trust that others that take a chance that it pays off - but thats life I guess.
Regards, Allan
PS I'm glad to answer any questions about the scope and its use. I attach a shot taken with a 350D of 4x5min with three darks at ISO800 of M20. Im more pleased with this shot that any other Ive taken. The only manipulation was a stretch in PS. Note that down sizing it really adds artifacts but I was really pleased with the extent of the faint blue nebulosity around M20 that is very hard to get except with a scope that does have good light coatings and baffles. No focal reducer or flattener used.

[dugnsuz (Doug)]

Very nice images Allan - the APO looks like a winner.
Doug