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Astrophotography and Sketching >> Beginning and Intermediate Imaging

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tjemi
member


Reged: 12/06/08
Posts: 10
Loc: LA, Ca and Tijuana, BC, Mexico
Cannot Focus
      #3426080 - 11/02/09 07:07 PM

Hello all,
I have a Zhumell 12' Dob and a Panasonic G1 mico4/3 camera which I have tried using for taking shots of the moon. I am using T-mounts, but could not get the moon in focus. It seems like the more I moved the camera toward the eyepiece the image cleared up, but at a certain point I could not focus further and the image was still very blurry. I have tried doing some searches here and on google, but am not sure how to proceed. Thanks.


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nofxrx
Vendor (HyperCams & Mods)
****

Reged: 07/12/05
Posts: 2501
Loc: Palm Bay,Florida
Re: Cannot Focus new [Re: tjemi]
      #3426169 - 11/02/09 07:57 PM

Hi,
Most of the time Newts need more "IN" focus for use with a camera.
There are several ways to fix this.
1)buy a new,low profile focuser like a MoonLight CR2.
2)Move the mirror "up" in the cell by using the collimation screws to move it up as far as possible,then re-collimate the optics and see if it helped.
3)take and drill new primary mirror cell bolt holes ~3/4" above the pre-existing set.This is EASY,many think they will ruin there telescope..you wont. Just simply remove the bottom/primary mirror.measure and mark at 3/4" or so center to center.Then drill a hole just large enough for the threads on the bolts to fit.re-mount the primary mirror cell.re-collimate.See how much it helped.

Those are about your only options IF the problem IS your optics....if it is your cam to eyepiece distance,then a new adapter may be needed.I found that using an adapter like this one helped me out the most when I tried eyepiece projection:
http://www.telescope.com/control/product/~category_id=photo_accessories/~pcategory=astro-imaging/~product_id=05338

Good luck!!

Oh,and WELCOME TO CN!!!

--------------------
Brent Oliver
WO-66SD*WO-Megrez102ED-Special Edition*Super C8 Plus*
CGE Pier-Mounted
Some Cameras,some Filters
HyperCams&MODS
My Gallery


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Igor
super member


Reged: 04/20/06
Posts: 126
Loc: Croatia
Re: Cannot Focus new [Re: nofxrx]
      #3426858 - 11/03/09 04:51 AM

If you are using eyepiece and camera with its objective (afocal projection) then there should be enough IN focus travel because otherwise you wouldnt be able to look through scope with your own eyes. So the problem is most likely with camera-eyepiece combo. What eyepiece focal length are you using? You should try to focus by looking through eyepiece and then focus image with your camera (if it has manual focus option).

--------------------
GSO 250/f5 dob
Skywatcher Explorer 130p @ EQ3
Baader modified 350D and bunch of old M42 lenses


Edited by Igor (11/03/09 04:55 AM)


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John Wunderlin
Vendor - Spike-a Focusing Mask
*****

Reged: 10/01/04
Posts: 699
Loc: Mineral Point, Wi
Re: Cannot Focus new [Re: Igor]
      #3427579 - 11/03/09 02:23 PM

Also make sure the camera is well centered in the eyepiece. If you're off to one side, you're effective uncollimated and you may not be able to get it focused.

--------------------
John Wunderlin
Vendor - Spike-a Bahtinov Focusing Mask
Empire Ranch Observatory
Iowa County Astronomers


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