My first attempt at Astrophotography with my new 10" Dob.

[Briddie]

[Tommohawk]

Only a novice, but looks like a pretty good start to me. What camera set up do you have?

[Briddie]

I have a Nikon D7000, the moon and nebula shots were taken at prime focus.

Jupiter was Ep projection through the cheap 10mm ep i got with the scope.

[Velvet]

not a bad start at all there

[Tommohawk]

So how did you mount the camera for Jupiter I wonder. Not hand held presumably!?

Theres load of info here about image stacking etc. I've played with it a bit, but need to get my hardware sorted first. I put a query out a little while back but so far 0 views 0 replies!!

[Briddie]

Thanks velvet.

[Briddie]

With a Revalation projection camera adapter.

[Tommohawk]

Ahh I see - just looked that adapter up, and realise you can fit eyepiece inside it. I have a lot to learn!

Does that make much difference to the mag comperd with prime focus?

[Briddie]

Yes it does, im very new to all this myself. Ive only had my scope a few weeks now.

[Tommohawk]

Well, off to a good start! Can you give me an idea how much mag differnce there is between prime focus and projection method?

[Briddie]

Try a look here http://www.12dstring.me.uk/fov.htm

[Tommohawk]

OK thanks, will explore that

[Briddie]

My images are all single shots. Ive been advised to take short video clips, then stack them in registax.

Every time i try with jupiter for instance, its completly over exposed. How do i get around this?

[Guy Wells]

With dslr? Cant you change the exposure with video?

[Briddie]

Im not sure, maybe i should try uping the frame rate if thats possible.

Im gonna go google that now.

[baggywrinkle]

Good start, Jupiter is very good and your Lunar shot is very sharp too.

[Briddie]

Thanks Baggywrinkle.

 

[Tommohawk]

Let me know how you get on with videp exposure issue please - I wondered that too.

[Pete Presland]

some very nice images there, the moon in particular is a cracker! the jupiter is pretty good as well.

[wxsatuser]

Well, off to a good start! Can you give me an idea how much mag differnce there is between prime focus and projection method?

Magnification over prime = ( distance from EP to CCD - EP focal length ) / EP focal length

Example........100mm from EP to CCD........EP focal length 20mm

Mag over prime = ( 100 - 20 ) / 20

Mag over prime = 4

So the image will be 4 times larger than prime.

The new focal length is ........Mag over prime x scope focal length

[Redbird48oo]

WOW looks great..... I just ordered a cannon 1000d, let the learning curve began. those shots really look great to me for just starting out. Hoping am half as lucky.

[Tommohawk]

Magnification over prime = ( distance from EP to CCD - EP focal length ) / EP focal length

Example........100mm from EP to CCD........EP focal length 20mm

Mag over prime = ( 100 - 20 ) / 20

Mag over prime = 4

So the image will be 4 times larger than prime.

The new focal length is ........Mag over prime x scope focal length

Fantastic! Thats really useful thanks, and nicely explained. Looking at the OP pics, and the relative sizes of the moon and nebula at prime, v. Jupiter with EP projection, I can see how that works.

I'm also wondering how this compares to the effective view with a digital eyepiece. Don't want to hijack the thread, but i think its related. Could you offer a comparison, even if its only an approximation. More than prime I think - and more than EP projection too?

[wxsatuser]

The only comparison I can give is prime and EP projection.

Use something like a Toucam in the FOV calculator.

Don't want to steal the thread.