Prime focus, need an adapter?

[Adz]

Hey guys,

I have recently been thinking that I have have jumped in the deep end of astrophotography.

Way before I bought my C8 I had my 350D and so I logically thought that if I wanted to snap Andromeda or Jupiter it would be with the Canon. But now I am learning that an initial webcam purchase may have been a more smoother progression...

My sister gave me a t ring for the canon for Christmas which I have been putting to work and playing around with. This is my current set up:

http://i1184.photobucket.com/albums/z327/add453/Equipment/DSCN2817.jpg

Now it is possible for me to attach the camera and t ring to the EP holder like this, without the need for an adapter (which everyone recommends):

http://i1184.photobucket.com/albums/z327/add453/Equipment/DSCN2818.jpg

and the OTA side of things:

http://i1184.photobucket.com/albums/z327/add453/Equipment/DSCN2819.jpg

But when I come to connect the two, the fixing screw at the top in the above image gets in the way of the built in flash:

http://i1184.photobucket.com/albums/z327/add453/Equipment/DSCN2820.jpg

So it leads to me starting to take prime focus photo at an angle:

http://i1184.photobucket.com/albums/z327/add453/Equipment/DSCN2821.jpg

is this possible?

I suspect that you guys will just say I will need to buy an adapter but I would appreciate your opinions anyway, cheers.

[Bizibilder]

That is exactly what happens with my 1000D s well! It is not too much of a problem in that you can still take photo's. The easiest way round it is to rotate the camera 180° to avoid the problem. It is rare that you cannot "wangle" it to get the object on the sensor. Don't worry about "up, down, left & right" - that can be taken care of using software like PS or whatever.

The problem with an additional (ie longer) adaptor is that you may then not be able to get focus - far more of a problem!!

[Glider]

That happens to me also. As Bizibilder says, it doesn't really matter. What you could try is replacing the offending bolts with shorter ones.

[glowjet]

I am shortly to take the path to the dark side, but to me, logically, the light path should be straight through to camera chip which should lie at 90 degs, yours will be at an angle therefore correct focus over the whole image should not be possible, this may also cause vignetting, if the fixing screw is a problem with the flash, why not rotate the camera through 90 degs to avoid it, or a small spacer is required HTH.

[glowjet]

In view of what bizibuilder has said forget the spacer, looking at the last two photos it looks as if a metric socket cap screw, in stainless if possible, cut to length so it just tightens to leave the head just above the locking ring, should give clearance to the flash unit, if both screws are adjusted so that the adapter just turns in the holder, the camera can be correctly orientated then finally locked in place by the opposing locking screw in the ring, the screw thread in the ring looks to be 3mm but check.

[Adz]

Thanks for all the advice guys, so you think that an adapter is definitely not needed?

If the camera at an angle like this is going to cause lack of proper focus or vignetting then I shall try and find another screw.

[Bizibilder]

I think what Glowjet means is that if the camera is like this:

http://i1184.photobucket.com/albums/z327/add453/Equipment/DSCN2820.jpg

You will have problems. As long as the adapter is fully "home" it will be absolutely fine.

As an added thought you could possibly simply remove the offending screw and rely on just one - a bit risky for my liking though!

PS I always wrap the camera strap around the finder or scope tube so that if the "grip" fails the camera can't fall far!!

[Adz]

I think what Glowjet means is that if the camera is like this:

http://i1184.photobucket.com/albums/z327/add453/Equipment/DSCN2820.jpg

You will have problems. As long as the adapter is fully "home" it will be absolutely fine.

As an added thought you could possibly simply remove the offending screw and rely on just one - a bit risky for my liking though!

PS I always wrap the camera strap around the finder or scope tube so that if the "grip" fails the camera can't fall far!!

The link doesn't seem to want to work but I know what you are getting at. I tried relying on one screw and I don't like it at all! There is also probably a tiny little bit of give, which is never a good thing if you are trying to take photographs. After taking your advice guys I have found the solution to work well for now, I shall endeavour to keep you posted with my pics

[Glider]

As Bizibilder says, the way you have it at the moment is fine. You can cut the bolts down as I suggested but it isn't really needed. I always tie the camera to the finder with its strap just in case!