A little help please

[bruno]

I've been trying to take pictures with my scope & camera but i can't seem to get any focus as the focuser won't go in to achieve max focus i've tried a barlow attached to the camera & i  can get a bit of an image of jupiter but it overexposed,but if i try to focus say like on a star in cassiopia i just get noise

[brantuk]

Hi Bruno. Are you using prime focus? Or do you have the diagonal on it with the camera attached to that?

For my Meg72 I take the barlow off and pop a T-threaded extender of the right size on to achieve focus. Focusing will also be affected if you use a reducer - the spacing from the reducer to the camera chip is critical. Hope that gives you food for thought.

[bruno]

Hi brantuk, I'm using a diagonal I do have a t-ring with a with a threaded piece which is about 35mm long can you get longer ones I also read that you need to measure the depth of the camera and the you need some thing thats a bit longer to achieve focus

[brantuk]

You can get longer T2 extenders here: http://www.firstlightoptics.com/adaptors/baader-t2-extension-tube.html

I use a flattener which has a T-Thread on the end of it to mount the dslr at the right distance for prime focus - it's this one:

http://www.firstlightoptics.com/reducersflatteners/skywatcher-field-flattener.html

I seem to recall the spacing from glass to chip is 55mm - I'm not recommending the flattener - just quoting it for the distance. You're scope's very nice and would justify a much better flattener/reducer lol.

I've used my 1000D with a diagonal in my Sct which is easy to get focus cos of the huge focus throw - but only used it with flatteners or reducers on refractors. So not sure what I'd do without a flattener - especially if "inward focus" is the problem....

The diagonal does add a lot of focusing length to the train so maybe a shorter "tube only" in place of it will give the required length. With my ST80 I measured the entire focal length from the lens with a tape measure. Then I estimated where the prime focal point would be and made up T-thread tubes from the focuser shoulder to place the chip within focus range. But that was for a ccd camera.

Hopefully someone else will comment - maybe someone with a scope like yours who's already configured a dslr to it.

[bruno]

thanks for your replies brantuk, have been and bought an extension tube one i can use with my threaded barlow. will give this a try hopefully will work fingers crossed will post on here if it does to help others

[Alien 13]

The comments by Brantuk are spot on most refractors require in the region of 2 inches of spacing to allow for the removal of the diagonal and when using a FF/FR the spacing is usually enough with the T ring on it own (within +/- 1mm of the correct FF/FR to sensor distance).

Alan

[lensman57]

I've been trying to take pictures with my scope & camera but i can't seem to get any focus as the focuser won't go in to achieve max focus i've tried a barlow attached to the camera & i  can get a bit of an image of jupiter but it overexposed,but if i try to focus say like on a star in cassiopia i just get noise

I think that I have the same scope and it has over 80mm of travel, and I do not have any problem focusing with either an ASI 120 , Atik CCDs or DSLR. How are you using the camera and what are the settings?

A.G

[bruno]

Hi lensman, Im using the camera with a threaded barlow on a t-ring set up in the diagonal & the setttings are 1/80th & iso 400 the shot comes out overexposed  but i can drag a bit of detail out have been told since that my iso is to high so i need to experiment. what scope have you got & have you got any recommeded setttings that might help cheers

[lensman57]

Hi lensman, Im using the camera with a threaded barlow on a t-ring set up in the diagonal & the setttings are 1/80th & iso 400 the shot comes out overexposed  but i can drag a bit of detail out have been told since that my iso is to high so i need to experiment. what scope have you got & have you got any recommeded setttings that might help cheers

I have the same scope as you, got it from Peter last Oct, I think tit is more suited to widefield DSO imaging than planetary but you can certainly use it for th is purpose. Why are you using a barlow? If you  going for the planetary imaging which think you are then you need a planetary webcam of somesort, a DSLR will not give you the  best results, however Jupiter  is very bright so try iso 400 and 1/250s and see what happenes.

A.G

[bruno]

went to see peter yesterday, he sold me  an extention tube  tried it last night an it works well without the diaogonal and the barlow, went the oppisite way though with the setting & got an under exposed shot of jupiter but on the good side i got a good picture of the star capella.

 I agree with you about the dslr but i'm still finding my feet at the moment & and i'm impatient wanting to run before i can walk will keep trying

[brantuk]

Glad Peter was able to help and you got sorted Bruno. I think everyone tries to run before they can walk in this hobby so you aren't alone - I know I did lol.

[bruno]

I will persevere with the dslr,i just ordered a uhc filter for it & my web cam adapter has arrived so i can play with that as well