Another Mars from Melbourne on 14-Jan

[MarkJ]

Hi all,

Image from Mars attached. Taken just before 5am on 14-Jan. from Melbourne.

250mm D-K, DMK618AU04 at 30FPS, Edmund filters.

Registax 6, Colours combined in PS then AstraImage

Mark

[John K]

Nice!

[Troy]

Good shot
Some nice feature visible.

[Stefan Buda]

Good to see that you dusted off the old scope and managed to produce Astrodon colours with Edmund filters.

[astronobob]

That pretty cool Mark, Id be wrapped with that !
You say 250mm apeture, F/Ratio ? & with a barlow/s, I assume yes be it a guess 4x ?
Got some good detail & colours there, Beauty :thumbsup:

[MarkJ]

Thanks John and Troy.

Stefan, yes good to get the scope out again.

Bob, Scope is 250mm F16 (4m focal length) used with a barlow at about 2.3x so effective focal length is about 9m at F36. I would probably prefer a little bit shorter/faster but with my current barlow arrangement this is the shortest/fastest I can get.

Mark

[rustigsmed]

Nice work Mark,

I think the conditions are looking good tonight, and i don't have to work tomorrow, you've inspired me to have a crack with the DSLR!

Cheers,

Rusty

[mbaddah]

Beautiful image! Well done.

[MarkJ]

Thanks Rusty, hope the conditions are good for you tomorrow morning. Skippy Sky predicts clears skies with reasonable but not great seeing.



Thanks Mohammed, glad you liked it.

Mark

[rustigsmed]

Thanks not looking likely about 3-4 small fires nearby now ...

[astronobob]

250mm @ F16, unreal, you'd need two people to carry it, one at each end with walky talky's ;) F16 would certianly aid in getting planet resolution, perfect scope in a lot of respects for the job. Intreguing to know, assume its a mirror, was custom made ? Ive never heard a scope of these dimensions, not doubting you at all, and if you get a high alt planet in steady conditions with it, well, Mind boggles ! !
Cheers for them specs :thumbsup:

[PacoYepes]

fantastic shot, I really like

regards

[MarkJ]

Thanks Paco, I'm glad you like it.




Sorry Bob, I have perhaps misled a little, the scope is not a Newtonian, it is a Cassegrain style or more correctly a Dall-Kirkam so the tube is only about a meter long.

Picture of scope here:

https://dl.dropboxusercontent.com/u/89672172/RyanAndScope2_small.jpg

Note that this shot was taken quite a few years ago and my son has grown a lot since but unfortunately the scope has not :(

Regards,

Mark

[blink138]

why have you attached a vacuum cleaner to your eyepiece for mark?
pat

[bratislav]

To keep the eyepieces clean, works much better than a broom ;) :lol:

(it is for vibrationless cooling of the primary - there is a fan at the end of the tube, and it can work at full speed with no visible vibration at the eyepiece/camera end)

[clive milne]

The main benefit might be to disrupt the chimney effect in the baffle tube and possibly pulling the boundary layer off the primary.

[blink138]

bugger me!! to the nth degree or what ha ha!
how rude of me anyhow mate the pic is great firstly!
pat

[astronobob]

Thanx Mark, i didnt know they made Cassegrains at F16 :thumbsup: Have you Not been feeding your scope weetbix, Lol :P ;)

[MarkJ]

Thanks Pat for your question and thank you Bratislav and Clive for the spot on answers.

The vacuum cleaner hose certainly does attract attention!

Credit to the scope's air venting system goes to the maker of the telescope who I bought it off some years ago. If he is listening he may like to comment.

Mark

[Stefan Buda]

Ok, I'm responsible for combining the vacuum cleaner with the telescope.
I wanted to reverse the air flow within the tube but I did not want to have the fan hanging of the back and introduce vibrations. I was using a flimsy mount with the scope and it did not take much to get it vibrating.

The scope I'm using these days is larger, with enough mass to cope with 3 smaller fans mounted directly on the back plate.

Stefan