More Penatx 200mm F2.5 lens images

[strongmanmike]

Last night was crystal clear and cold in Canberra so I took advantage of it to do some more testing of the Pentax 200mm lens.

With the 200mm lens stopped down from F2.5 to F3 (a half stop only) I first took 4hrs 15min worth of Halpha data in 10 and 15min subs of the Tarantula region of the LMC:

130k image:
http://www.pbase.com/strongmanmike2002/image/69298485/large

550K image:
http://www.pbase.com/strongmanmike2002/image/69298485/original

Then in the last hour before dawn I managed to get 40min worth on The Rosette before the sky got too light:

110K image:
http://www.pbase.com/strongmanmike2002/image/69299821/large

550K image:
http://www.pbase.com/strongmanmike2002/image/69299821/original

Overall I was very happy with the evenings run. The lens is obviously quite good particularly in Halpha even with an almost wide open aperture - here is the setup:

http://www.pbase.com/strongmanmike2002/image/69199959/large

I was using the AP for autoguiding with the SX external guide head connected to the SXV-H9 and the average errors throughout the night were < 0.1 pixels or about 0.27" - not that a 200mm lens needed this sort of accuracy of course. Having a pristene sharp star image to guide on seems to help.

Have a nice rest of the weekend :thumbsup:

Mike

[Ric]

Hi Mike,they are fantastic images, the detail and clarity is spot on. That lens is definitely the bee's knee's.
It certainly was a great night last night the temp dropped down to the chilly side and the sky was very crisp and clear in the early morning. My DSI was enjoying the chilled air.

great stuff

[Dennis]

Hmm, very nice image there, Mike. Food for thought when I'm next considering upgrading my ccd camera. What camera control software do you use?

Cheers

Dennis

[Garyh]

Great work Mike...:thumbsup: nice and deep there...
I love these pentax lenses, they hold up well to any other brand out there!! even the older m42 ones are tack sharp.
Coupled with your SX ccd camera you should get some awesome widefields now.
Cheers Gary

[atalas]

Excellent work Mike !

[strongmanmike]

Man am I jealous of your property now!!!

Although it is clear that good images can still be captured under light poluted soup just takes longer.

Cheers

[strongmanmike]

I have used Astroart exclusively for over 3 years now. I control the camera with it and do all the initial aligning and combining in it then copy and paste the Fits file into Photoshop 6 for the tweeking.

The camera control interface is excellent, visually simple and intuitive.

Mike

[RB]

Superb images Mike.
Which Ha filter are you using btw?

[strongmanmike]

Thanks Gazza!

This 200mm F2.5 Pentax Lens is 1985 vintage but has been hardly used so I was looking forward to finally shooting through it - thanks Steve Mogg of Mogg Adapters!!

It is a genuine Pentax SMC lens and stopping down just half a stop to F3 was all that was necessary in Halpha. Not sure how LRGB will go though and hopefully Steve Mogg will develop a thin adapter that allows for filters to be inderted without dismantling, while still allowing for infinity focus to be reached - he will look be looking at it next year I believe?

Mike

[strongmanmike]

Thanks big Louie :-)

[strongmanmike]

Thanks

I use an Astronomik 13nm - still cuts through the LP ok

Mike

[Ric]

Hi Mike, I'm jealous of my property as well because I'm still in Queanbeyan until I finish building the house. Hopefully not too long now.

cheers

[Octane]

Mike,

Both unreal images.

So crisp and detailed.

Excellent work.

Regards,
Humayun

[fringe_dweller]

hey the old 80's pentax primes rock! very, very nice Mike, superb!
I can never remember all the lenses (leaky memory - and to lazy to google), is this a medium format lens or a 35mm job? looks like a 35mm in pic?

[Striker]

Some wonderful HA images Mike.

I love that Rosette.

I would get rid of that cheap guide scope...when your ready let me know...lol

[strongmanmike]

No worries Tony...ooooh?...12G's and I miiiight think about it LOL :-)

Nah, it's a collectors item and would be like selling my child.

Mike

Mike

[2020BC]

Nice Rosette at only 40 mins - and no darks required!:thumbsup:

[strongmanmike]

Hi Bill

Yes the SXV-H9 is a marvelous camera and without the need for darks is a dream to use. A 35mm size chip version would be bloody marvelous :D

Mike