Focus problem with DSLR

[pecham34]

Need much help.
I'm treying to use D3100 with an ED120 refractor.
I've attached the Tmount to SLR camera to telescope adaptor and fitted into 2" diagonal, but can't get focussed using live view, or through the viewfinder.
Obviosly doing something wrong, very new to all this and spend much time between moderate and extreme confusion.
pecham34 :help:

[Chris.B]

Sounds like a back focus issue.
Try remove the diagonal and it should come to focus.

The Tmount should be able to be screwed onto the focusser shortening the distance a lot.

[bokglob]

With your scope you'll need more backfocus. Ditch the diag and fit an 80mm extension tube:thumbsup:

[2stroke]

I think your real problem is that you aren't in bulb mode and or have the iso set to low like 100 when it should be at 800/1600. lol i doubt back focus is the issue if its close to the ed100 i own but prove me wrong :)

Another thing I missed because i'am a canon user not a nikon, just use the moon and center it, lol your got stuff all chance seeing a star on your liveview unless you can zoom in with out knocking the scope haha. I have no idea what software supports nikon's but if you can get something like apt/byeos it will make life way more easy. All my shooting is done through byeos and i use the cannon utils to focus the scope, maybe nikon have some software which lets you do this ask around. I'am sure the nikon boys can help you out anyhow.

[pecham34]

Many thanks to all.
Ditched diagonal and achieved focus via 2*barlow, but Sun and Moon overflow frame.
Removed several components from the connector and got focus, but will probably need 40mm extension tube to avoid holding everything together with the thumbscrews.
Shame about the diagonal, will need contortion training to get behind the camera.
Will pursue camera control via laptop when more accomplished; suspect I'm at the bottom of a V steep learning curve
Once again lots of thanks
:thanx:

[cjamo9]

ive unscrewed the lense out of an old barlow it works as a great extender without the magnification.:thumbsup:

[White Rabbit]

Plug your camera into laptop if you have one and use live view on the screen rather than putting you back out trying to get under the scope.