Pictures with my 20cm F/2.75 ASA Astrograph

[Albert van Duin]

Hello all,

In July 2006 I visited the Qeensland Astrofest and made some nice pictures with my Nikon D70 on Renato's mount. At the Astrofest there were a lot of modified Canon camera's and I liked the results very much. So when I got home I converted a Canon 350D with a Baader UV/IR filter and started imaging. Soon after that I got my hands on a 20cm F/2.75 ASA Astrograph. The first results are at:
http://members.home.nl/technoplus/
But the last 3 weeks were cloudy here so no new images since December.
I guess we are going to miss comet McNaught over here. It's up to you now!
I'm still dreaming of the beautifull nights at the Astrofest.

Regards,
Albert van Duin
Netherlands
53 North 6.5 East

[gbeal]

Very nice gallery Albert. I especially liked the Horsehead.
The ASA looks nice too, I am thinking to maybe build a similar beast, maybe not F2.75, but near F4. This will depend on what I do with the Takahashi FC100.
Oh, BTW, welcome to IIS.

[iceman]

Wow, they are stunning shots! Very nice indeed.

As Gary said, :welcome: to IIS!

Mike Sidonio just got the 12" ASA, I can't wait to see the results he gets after seeing your 8" versions!

Congrats on beautiful imaging!

[Striker]

Welcome Albert,

Good to see another ASA come to the forum.
Some nice images aswell.

Albert is that vertical banding from the camera thats more noticeable with Orion and the horsehead.

[strongmanmike]

Hey Albert

That's the best collection of ASA images out side Wolfgang Prompers stunning assembly, well done mate :thumbsup:

Given the faster F2.75 range of ASA astrographs was only designed to correct an image circle to cover a bit more than the 18mm diagonal of the Kodak 3200 chip (ST10), your images show it is quite good even for DSLR APM size chips (33mm diagonal).

The variation in star image shape across your shots seem to suggest that much of the star elongations noticable at the edges may just be from collimation error?

All very nice shots, well done! :thumbsup:

Mike

[glenc]

Hi Albert
Good to hear from you.
Nice selection of objects and well imaged too. :thumbsup:
CS
Glen

[h0ughy]

Greetings Albert, i was one of the voices in the dark at Duckadang last year. yes they were top nights, I stayed up for 3 complete nights! Nice scope

[Ric]

Hi Albert and welcome, loved your selection of images.

Very nicely done.

[astroron]

:hi: Albert, great to see you have joined our group:thumbsup: , they are fantastic images:eyepop:
I look forward to more of your images in the future:)
In you pic of your scope you have somthing sitting on the fence, is it a bird or a model or something?:shrug:
Look forward to seeing you again at Duckadang in the future.
Ron of the 16"dob fame:lol:

[jjjnettie]

Your photos are exceptional!
Beautiful work Albert.
Astrofest is a great event, very social. Were you the fellow looking for a lift to the airport?

[acropolite]

Lovely images Albert, nice to have you on board. :)

[Dennis]

Hello, Albert

Wow – what a way to say hello once more!

For those who do not know, Albert is a very talented and well known European astrophotographer from the Netherlands and a familiar visitor to these shores. Albert and a contingent of fellow astronomers from the Netherlands visited the Qld Astrofest in 2003 with their tour guide, the late Erwin Van der Velden. When their vehicle arrived at the camp, I was amazed to see how many people, and how much equipment, was disgorged from the bowels of the vehicle. It reminded me of one of those “how many people can we get in this mini van” challenge from my days at Uni.

Albert and his wife Ina also dropped in to visit Astrofest once more, in 2006 this time introducing us to Erwin’s sister Ilse Van der Velden and her husband Gert. I spent some time with Albert chasing down some problems Gerald was having with his new Atlux and Skysensor 2000 – Albert has adapted the Vixen SS2K to his Losmandy G11.

Anyhow, hope that isn’t too much information about you, “Albert from Dune”.

Cheers

Dennis

PS –here is Albert at the Qld Astrofeast with Renato’s profile in the background.

[astroron]

:hi: Dennis ,thanks for the bio of Albert. I had a great time in 2003 showing the group some southern wonders through the 16" ,and was pleased to see Albert and Ilse again at AstroFest last year:) .
I hope we see them again in the years to come:thumbsup: Ron

[Albert van Duin]

Hello everyone,

Thanks for the nice welcome and comments, I'll try to answer some questions in this post, otherwise I'll have to do a lot of postings...

I'ts good to see some familiar names again!


Yes it is banding due to curves stretching to the limit. As you can see in the unprocessed Horsehead image a lot of stretching was needed to get the details out. If you use a good flatfield it will go away almost completely.
You can find an example of this in the NGC891 image.


The ASA wasn't perfectly collimated yet but ist has been cloudy ever since I got my Catseye tools! :mad2:


Ron, it is plastic Rainbow Lorrikeet that was placed there by our neighbours. :)


No, I think that was a guy from France if I remember correctly.

Thanks Dennis!

As soon as I have more results I will post them here.

Clear skies and enjoy Comet McNaught!

Regards from rainy Holland,

Albert

[Garyh]

Hi Albert, Welcome to IIS! a nice collection of images there!!! Very sharp and colorful!!
Looks like you have some vignetting there for the canon ccd sensor to deal with. You have done a excellent job with removing the gradients. Is it possible to alter your ASA astrograph to fix this? A larger secondary? I guess a f/2.75 would have a very large secondary already..
My grandparents are from your way many years ago!
Cheers and hope you get some clear skies..
Gary

[Albert van Duin]

Hello Gary,

Thanks for your nice comments.
The corrected field is about 20mm while the diagonal of the Canon chip is 27mm. The only way to improve this is to change the focuser and corrector.
I now have a 2 inch corrector but it could be replaced by a 3 inch version.
The secondary is quite large already.
On the other hand, if I use a flatfield the vignetting is not noticeable.

At te Astrofest I met two Dutch speaking amateurs from Australia, John and Daniel, there seem to be quite a lot of people with roots in the Netherlands in Australia!

Regards,

Albert

[spearo]

Very nice gallery, excellent website too
welcome to IIS
frank