How can you focus the scope for photography

[h0ughy (David)]

This is one of those questions that has been a problem to me and no doubt wll be highlighted even more so when I try for more imaging of the heavens.

How the heck can you achieve focus when you attach the camera in the prime focus position on the scope????

[Robby]

Trial and error! It also depands on the camera, but generally image - download - focus -image -download - focis etc etc etc...
With the 300D I use DSLR focus. Takes about 10mins is acheive decent focus.

Astrophotography is a sport of patience. If I'm setup ready to image in 40mins I am doing very well...
1. Check polar alignment - 10mins (I have a portable ssetup arrghhh)
2. Find desired object with normal EP - 1 to 15mins depending on the object!
3. Replace EP with camera - 1min
4. Focus, focus, and focus. - 10mins (I know how to get close manually, & then just finish off with trial & error method as above.
5. Center object in camera frame. - 5mins (Again trial & error. Take image, move scope, take image etc.
6. Find a guide star - 5mins
7. Align guide camera with guide star. - 5mins (I use K3CCDTools2 for guiding)
8. Start imaging 40mins - 400mins!
9. Go inside watch TV, browse IIS, & wait! Oh I wish I had a dob so I could do some viewing while imaging...

Ok, so I drifted off-topic a little... but you get the idea!
Cheers

[RB (Andrew)]

Dave for my 300D I use the right angle finder which attaches to the viewfinder and allows me to spin it around to any angle for comfort.
It also has a 1.25x and 2.5x mag switch which helps get closeup views of star points.
Then I do some test images and adjust as needed.

I'm not familure with the Pentax range though.

Also DSLR focus will be great. It's tops.
You can use it but you'll have to transfer the files across manually I think.

Cheers

[[1ponders] (Paul)]

h0ughy if your going to try Robby's first suggestion consider using a hartmann mask as well. Before I had DSLR Focus I found I could get reasonable focus using this technique though it is a slow process. Consider DSLR Focus. It may be a bit trickier to setup using the pentax but from reading the manual I believe it should be possible.

cventer would be able to tell you

[h0ughy (David)]

Thanks guys!

[Robby]

Originally Posted by Rocket Boy

You can use it but you'll have to transfer the files across manually I think.

You can set DSLRFocus to monitor a directory, so as you download a new file to a directory it automatically comes up in DSLR Focus... Still a bit of a hassle though!
Cheers

[Striker (Tony)]

Houghy,

I am using DSLR focus.....even though I feal I can adequietly focus easily through the 20DA zoom focus setting...takes me a whole 30 seconds to do so...this is said to be not the case....DSLR Focus has some great functions.

I just purchased the DSHub from shoestring so I can control all my exposures from my PC at what ever length...instead of the 30sec max.

http://www.store.shoestringastronomy...roducts_ds.htm