DSLR lack of in focus

[saturn5]

Went to take my first prime focus pics last night and couldn't get enough in focus,i'm assuming others have had a similar problem and wondered what they did to get around it.

I'm using a revelation crayford and just when the flange of the 1.25" ep holder comes up against the 2" to 1.25" adaptor the image is just starting to focus.

If i made an adaptor which fitted the 2" o.d and bored out to take the 1.25" i.d but made it parallel so there is no flange on it this would do away with the 2" to 1.25" adaptor and offending flange and give me approx 6 to 8 mm more in travel.

Or take the adaptor plate which connects the focuser to the ota and mill the same amout of the bottom of it,

or both of the above.

Hope the above makes sense.

[GazOC]

If you are 'nearly there' you could try collimating the primary further up the tube?

[saturn5]

Never thought of that one Gaz,thanks for that.

The image was just starting to sharpen up so i'm not sure how much more travel i might need but i'm assuming it only to be a few millimeters,certainly no more that 5 anyway.

[rawhead]

If you are 'nearly there' you could try collimating the primary further up the tube?

Worked for me :thumbleft:

[saturn5]

Moved it up as far as i could.I need it all as i cant get past focus to come back again but i posted a moon pic and its not far of focus wise.