Short exposure astrophotogrophy?

[Manok101]

I've been told that long exposure is out of the question but was pointed to short exposure photography and was wondering what I needed?

[E621Keith]

Short exposure. That will be lunar and planetary imaging. You will need a modified webcam with an adaper to connect it to your scope and a scope on a reasonably stable mount and a laptop.

[Digz]

Why were you told that long exposure photography was out of the question?

What exactly do you want to photograph?

[Deneb]

Have you thought about unguiding camera work, you could say that is short exposure astrophotography...

Nadeem.

[Demonperformer]

Quite a lot can be achieved with short exposures: http://stargazerslounge.com/imaging-discussion/130288-wouldnt-have-thought-possible.html

[E621Keith]

Why were you told that long exposure photography was out of the question?

Both op's scopes are dobs (according to his signiture), which may explain why people say it is not suitable for long exposure photography.

[Digz]

Good point, I missed that.

Still Im sure a lot can be done with a Dob.

[ismangil]

If it's just about Dobs mount, has anyone ever tried the equatorial platform product? You put your scope on top of it, base and all, and it tracks!

[Capricorn]

Why are they called Equitorial?

They are not equitorial as an EQ5 mount.

My Alt/Az goto has motors in both Alt and Az axis to track an object.

As best I can tell these bases are simply a motorised rotating base. So you have an undriven Alz/Az mount on a rotating base, so they do not track even in RA accurately.

It just seems to be somewaht misleading to potential purchasers for them to be termed Equitorial, especially in this hobby.

[Digz]

It certainly is a misleading term.

Personally I not convinced by this product for AP but my opinion is based on pure speculation as I am not familiar with the mechanics involved.

[rowan46]

I am pretty sure they are not just a motorised base if it was there would be no need to polar align it. must admit I have no idea how it works though. moonshane will know he's built one.

[E621Keith]

I thought equatorial platforms were an adjustable ramps similar to a wedges, in which they get polar aligned and then the dob get put on top. May be not, otherwise I guess it would be nerve-racking for low latitude users.

Anyway, I heard dob tubes have quite a lot of flex, they're ok for visual but probably not the best for long exposure.

[Manok101]

My scope does track if that makes a difference.

[Demonperformer]

If it is a tracking dob, it is like having any other alt-az motorized mount, and you should be able to get reasonable sub-lengths. On my mounts I can usually get upto 30 seconds without any problem, and that can give quite reasonable results. The problem you will have is field rotation - the objects will rotate round the centre of the frame if you expose for too long - this will be most visible at the edges.

HTH