Can I ask advice of the imaging people here

[Ukastronomer (Jeremy)]

Really basic question please

I have the following

from left to right

120 triplet------baader clicklock-------baader 2" diagonal---------camera (DSLR)

However, and it may be me, I can not rack the camera "out" far enough to focus, is that the right expression.

It is as if I need to rack it out another 1-2"

Also, I have the same problem viewing the sun

120mm scope---------baader clicklock--------2" IR cut filter ON diagonal----------baader 2" diagonal-----------quark------------eyepiece

Cant get "back/out" enough to focus

Thank you

???????????????

[MortonH]

If your focuser needs further outward travel to reach focus then an extension tube or spacer(s) is required. Various lengths are available.

e.g.

https://www.firstlightoptics.com/ada...t-adapter.html

https://www.firstlightoptics.com/ada...-tube-set.html

https://www.firstlightoptics.com/ada...-tube-set.html

[Ukastronomer (Jeremy)]

Thanks, so they just fit

diagonal ------------- spacer ------------- dslr

, what a fool, many thanks

[xelasnave]

Perhaps no diagonal if you can use the appropriate extention tubes.
Alex

[Outcast (Carlton)]

+1 for this Jeremy,

If you can add the right amount of extension tubes/spacers to come to focus, lose the diagonal, it's another absorber of vital photons that can be removed from your photo equation... Every time light passes through something or bounces off something, you lose photons..

Originally Posted by xelasnave

Perhaps no diagonal if you can use the appropriate extention tubes.
Alex

[Ukastronomer (Jeremy)]

Thank you

NO diagonal

Appreciated

[sil (Steve)]

If you try focusing then remove the diagonal, lock up[ the mirror on your camera so the sensor is exposed and turn on live view you just hold the camera out from the cliklock pretending you have an extension tube. As you move the camera ford/back you'll see live view come into focus and out again. Hold it where focus roughly look best and measure the distance from cliklock to camera mount to find the approximate length of extender tube needed. actually wind the focuser halway in and do this so you have leeway either side for focusing. try to avoid building up short tubes to make the size each tube join becomes a weak point for light leaks, flexing and "oops I bumped it and it span off in the dark onto the concrete"