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IIRC you are supposed to set it to "infinity"....
I remember shooting planets afocally and would usually set it to infinity but would on occasion mess with the focus until I got what looked best...
Hope this helps!!
By the way what adapter are you using to hold the cam to the EP?

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Thanks for the reply.

I'm going to use a Agena 20mm UWA, which has 49mm threads under the eyecup, and I've got a 49mm to 52mm ring screwed into a 52mm to 49mm ring which screws right into the Lensmate I've got on my PowerShot G2. The combination of rings is just enough to keep the camera lens from hitting the eyepeice, and I was able to get them a local camera store.

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Clear Skies

Tom

Nexstar 8 GPS
GSO 8" Dob
Meade ETX 80
Kendrick Dew Heater
11mm, 20mm Agena Astro UWA
40mm, 32mm, 26mm, 20mm and 15mm Meade Series 4000 Super Plossl
25mm and 10mm GSO Plossl, GSO 2x barlow
Surplus Shed 47mm Erfle
GSO 2" Dielectric diagonal
Antares f6.3 focal reducer
Philips SPC900NC

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Some cameras actually work better in macro mode. My old Nikon 4500 was like that but my Canon A610 works best at infinity.

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I guess I'll give both a try then...

Thanks for the reply.

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Clear Skies

Tom

Nexstar 8 GPS
GSO 8" Dob
Meade ETX 80
Kendrick Dew Heater
11mm, 20mm Agena Astro UWA
40mm, 32mm, 26mm, 20mm and 15mm Meade Series 4000 Super Plossl
25mm and 10mm GSO Plossl, GSO 2x barlow
Surplus Shed 47mm Erfle
GSO 2" Dielectric diagonal
Antares f6.3 focal reducer
Philips SPC900NC

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Really nice attempts! Its encouraging me to get the lensmate set up for my Canon S3is from CNC supply! Those halos look suspiciously like something fogged up.

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Thanks.

I hadn't thought of dew since my dew heater was doing such a great job of keeping my corrector clear. There was awful lot of dew on my patio table and chairs. I suspect you are right.

Maybe it's time to pick up any eyepiece strip for my dew heater...

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Clear Skies

Tom

Nexstar 8 GPS
GSO 8" Dob
Meade ETX 80
Kendrick Dew Heater
11mm, 20mm Agena Astro UWA
40mm, 32mm, 26mm, 20mm and 15mm Meade Series 4000 Super Plossl
25mm and 10mm GSO Plossl, GSO 2x barlow
Surplus Shed 47mm Erfle
GSO 2" Dielectric diagonal
Antares f6.3 focal reducer
Philips SPC900NC




Edited by tjay (09/25/08 10:14 PM)

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Those are great!!!
The Halo effect is from vignetting.This can happen from several things: the .63 reducer,the distance from the eyepiece to the cam, or a combination of both...
The only reason you didnt get it on Jupiter is because it was at a short exposure,the longer exposures will show this more so.Also stretching the image in PS will bring this out more.
I had one of those adjustable adapters like THIS ,which would allow me to move the cam around to find that "sweet spot" where the vignetting would be less...you could also try zooming in until the vignetting is less,or more manageable.
Your M57 is really good,plus you got some color in there
Definitely keep trying,if your results are this good starting out I cant wait to see where you are in a year or so!!!

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Brent,

Thanks for the encouragment.

Would a bracket like yours help with the vignetting if I'm already getting the camera lens really close to the eyepiece?

I suspect there are only a few millimetres separating them since I'm only using a couple of adapter rings to attach the camera to the eyepiece.

--------------------
Clear Skies

Tom

Nexstar 8 GPS
GSO 8" Dob
Meade ETX 80
Kendrick Dew Heater
11mm, 20mm Agena Astro UWA
40mm, 32mm, 26mm, 20mm and 15mm Meade Series 4000 Super Plossl
25mm and 10mm GSO Plossl, GSO 2x barlow
Surplus Shed 47mm Erfle
GSO 2" Dielectric diagonal
Antares f6.3 focal reducer
Philips SPC900NC

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Actually Tom,sometimes there needs to be more space between the lens and eyepiece lens than that..
It really depends on the EP...I have an Orion 3.8mm Epic and it "blacks out" near the EP lens,visually or with the cam.
I doubt that is the problem.it is more than likely the spacing from the reducer to the EP/cam...are you using a diagonal? if so try it without it,maybe it will help. If not then maybe it needs a short extension tube...With my limited knowledge of optics I would suggest trial and error until you find what works for you the best...

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Thanks. I was just wondering if there was any possibly that the bracket would help. Sounds like there is. I'll give it a try with the focal reducer on the next clear night too.

--------------------
Clear Skies

Tom

Nexstar 8 GPS
GSO 8" Dob
Meade ETX 80
Kendrick Dew Heater
11mm, 20mm Agena Astro UWA
40mm, 32mm, 26mm, 20mm and 15mm Meade Series 4000 Super Plossl
25mm and 10mm GSO Plossl, GSO 2x barlow
Surplus Shed 47mm Erfle
GSO 2" Dielectric diagonal
Antares f6.3 focal reducer
Philips SPC900NC

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I don't know if this is the same as you are using, but I thought I would pass it along!
http://www.cncsupplyinc.com/digikits.htm

Just scroll down to find your camera model.

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Thanks.

I've seen these. I kind of "rolled my own" with the step up and step down rings I'm using.

--------------------
Clear Skies

Tom

Nexstar 8 GPS
GSO 8" Dob
Meade ETX 80
Kendrick Dew Heater
11mm, 20mm Agena Astro UWA
40mm, 32mm, 26mm, 20mm and 15mm Meade Series 4000 Super Plossl
25mm and 10mm GSO Plossl, GSO 2x barlow
Surplus Shed 47mm Erfle
GSO 2" Dielectric diagonal
Antares f6.3 focal reducer
Philips SPC900NC

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I'm extremely encouraged by the results for M57, but I'm not clear why I got a halo around everything other than Jupiter. Anybody have any thoughts?

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Looks like vignetting to me - sometimes it's because the light path is blocked but in this case it looks like the light cone just falls off very rapidly.

Did you use any zoom in these shots at all? I started imaging using a DV camcorder tied to the eyepiece pretty much the same way you have done, and I would get this kind of vignetting when I used the optical zoom on the camcorder:



Here's another shot - same basic setup, but no zoom:



My guess is that you might actually have the same issue with the Jupiter shot but the background is so close to the same level that you cannot tell the difference.

Charlie

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Weston CSC:

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I'm extremely encouraged by the results for M57, but I'm not clear why I got a halo around everything other than Jupiter. Anybody have any thoughts?

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Looks like vignetting to me - sometimes it's because the light path is blocked but in this case it looks like the light cone just falls off very rapidly.

Did you use any zoom in these shots at all? I started imaging using a DV camcorder tied to the eyepiece pretty much the same way you have done, and I would get this kind of vignetting when I used the optical zoom on the camcorder:

image deleted

Here's another shot - same basic setup, but no zoom:

image deleted

My guess is that you might actually have the same issue with the Jupiter shot but the background is so close to the same level that you cannot tell the difference.

Charlie

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I definitely did use the maximum zoom on my camera. I'll try without next time. Thanks for the tip.

--------------------
Clear Skies

Tom

Nexstar 8 GPS
GSO 8" Dob
Meade ETX 80
Kendrick Dew Heater
11mm, 20mm Agena Astro UWA
40mm, 32mm, 26mm, 20mm and 15mm Meade Series 4000 Super Plossl
25mm and 10mm GSO Plossl, GSO 2x barlow
Surplus Shed 47mm Erfle
GSO 2" Dielectric diagonal
Antares f6.3 focal reducer
Philips SPC900NC

Post Extras: