Rho Ophiuchi widefield Proline 16803 165mm Pentax

gregbradley · #1 17-10-2011, 06:41 PM

I have been using these Pentax 67 lenses for a little while now.
The 55mm F4 is OK but needs to be stopped down a bit and run at 2x2 binning to get rid of aberrations but is nicely very widefield. The 165mm F2.8 though runs fully open with little to no aberrations except a bit of chromatic aberration.

It lacks the resolution of a telescope but still fun. Bright stars come out a bit magenta and that needs to be processed out but otherwise it shows up a nice area reasonably well.

I took this one a while ago. I don't think I've nailed the processing yet but it didn't turn out too bad.

3 hours 15 minutes. 5 minute subexposures, F2.8, 2x2 binned, LRGB:

http://www.pbase.com/gregbradley/image/138661800/large

Greg.

Lester · #2 17-10-2011, 06:51 PM

Exceptional view, thanks Greg.

jjjnettie (Jeanette) · #3 17-10-2011, 06:56 PM

I love this region, there's so much happening. Thanks for the view.

SkyViking (Rolf) · #4 17-10-2011, 07:44 PM

Great view and excellent colours. It's a spectacular area, and well captured!

batema (Mark) · #5 17-10-2011, 07:44 PM

Beautiful colours and a lovely image. It looks fantastic.

Mark

h0ughy (David) · #6 17-10-2011, 07:46 PM

its great to see images like this - reminds me of what the sky looks like - havent seen it for quite sometime

RickS (Rick) · #7 17-10-2011, 07:56 PM

Lovely colours and dust, Greg!

Ross G · #8 18-10-2011, 05:27 AM

Hi Greg,

Your photo looks great.

Love the colours and the wide FOV.

The quality of your Pentax lens is obvious.

Thanks.

Ross.

gregbradley · #9 18-10-2011, 09:05 AM

Quote:

Originally Posted by Lester

Exceptional view, thanks Greg.

Thanks Lester. I like these widefields. This represents about 12 panels of a mosaic with an FSQ and reducer and the 16803.

Quote:

Originally Posted by jjjnettie

I love this region, there's so much happening. Thanks for the view.

Thanks JJ. It is the probably the most colourful part of the Milky Way.

Quote:

Originally Posted by SkyViking

Great view and excellent colours. It's a spectacular area, and well captured!

Thanks. I am happy with this little Pentax 67 165mm lens. Its a keeper.
The 55mm one shows more coma but is still usable. The 300mm is like a telescope and also shows no coma.

Quote:

Originally Posted by batema

Beautiful colours and a lovely image. It looks fantastic.

Mark

Thanks Mark.

Quote:

Originally Posted by h0ughy

its great to see images like this - reminds me of what the sky looks like - havent seen it for quite sometime

Yes it has been cloudy lately hasn't it? I like this lens its a good match with the Proline.

Quote:

Originally Posted by RickS

Lovely colours and dust, Greg!

Thanks Rick.

Quote:

Originally Posted by Ross G

Hi Greg,

Your photo looks great.

Love the colours and the wide FOV.

The quality of your Pentax lens is obvious.

Thanks.

Ross.

Thank Ross. These Pentax lenses are a bargain. I forget exactly how much I paid for it but it was something like US$250 or perhaps less on Ebay where there are lots of them.

Greg.

Stevec35 (Steve) · #10 19-10-2011, 09:38 AM

Nice colours Greg. A well composed shot.

Cheers

Steve

strongmanmike (Michael) · #11 19-10-2011, 12:48 PM

Wow what a field Greg

...you are going to have some fun with that setup I can tell. Looks like you have worked on the stars, I assume to remove the magenta halos? If you can improve this aspect I think you will produce some corkers with this setup...man, how many amazing optical trains do you have now

Mike

gregbradley · #12 19-10-2011, 10:17 PM

Quote:

Originally Posted by Stevec35

Nice colours Greg. A well composed shot.

Cheers

Steve

Thank Steve.

Quote:

Originally Posted by strongmanmike

Wow what a field Greg

...you are going to have some fun with that setup I can tell. Looks like you have worked on the stars, I assume to remove the magenta halos? If you can improve this aspect I think you will produce some corkers with this setup...man, how many amazing optical trains do you have now

Mike

Thanks Mike. Yes I have a few!

Yes some work on the stars and not perfect either. I was thinking of reprocessing from the ground up but other projects to work on.

I have a mosaic to stitch together.

Greg.

atalas · #13 22-10-2011, 07:44 AM

Nice work Greg,a unique looking composition.

gregbradley · #14 22-10-2011, 08:43 AM

Thanks Louie. I wanted to get the Blue Horsehead in it as well so I positioned the image that way.

Greg.

tornado33 · #15 22-10-2011, 10:06 AM

In the old days of film it would take a dedicated schmidt camera to take images like that. Well done
Scott

gregbradley · #16 22-10-2011, 12:07 PM

Thanks Scott.

I have a 4 panel (intended 6 panel if I can get it) mosaic to put together as well from the same lens.

I have to get my processing routine down pat for this lens as it has slightly different problems to my normal telescope images.

Greg.

multiweb (Marc) · #17 24-10-2011, 05:46 PM

Huge FOV and very vivid colors. Nice one.

gregbradley · #18 24-10-2011, 07:16 PM

Thanks Marc.

It turned out to be a good lens. The 300mm F4 seems to be good as well.
What was that filter you got for your lens? Did that reduce the chromatic aberration (the odd magenta bright star)?

Greg.

multiweb (Marc) · #19 24-10-2011, 07:36 PM

Quote:

Originally Posted by gregbradley

Thanks Marc.

It turned out to be a good lens. The 300mm F4 seems to be good as well.
What was that filter you got for your lens? Did that reduce the chromatic aberration (the odd magenta bright star)?

Greg.

2" Baader Fringe Killer. They retail at approx. $50.00. Worked a treat for me. A must for an OSC. Not so much for a mono IMHO.

gregbradley · #20 24-10-2011, 07:38 PM

Quote:

Originally Posted by multiweb

2" Baader Fringe Killer. They retail at approx. $50.00. Worked a treat for me. A must for an OSC. Not so much for a mono IMHO.

Thanks Marc. Where did you get it from?

Did it need an adapter to fit the lens?

Greg.