Focal Reducer for Skywatcher ED80?

[moondog]

Been looking for a reducer for the ED80.

I've remember some images being posted that were taken with an ED80 with, I think, an F6.7 reducer.

I have a Celestron F6.3 reducer for the C8 but I can't get it to work with the ED80

I also understand that the Williams Mk III reducer/flattener doesn't work.

Any ideas?

MD

[russ]

I have a Celestron F6.3 reducer for the C8 but I can't get it to work with the ED80

That combination should work perfectly MD. I've used the Celestron f6.3 with both the ED80 and ED100. Do you mind me asking how you are setting it up?

Regards

Russ

[moondog]

Rus

I fitted a 2 ins nosepiece which had a thread to take the SCT reducer into the scope focusser and then used a Williams SCT to 2ins nosepiece to fit EP's/Camera.

Didn't seem to be able to get sufficient inward focus

MD

[russ]

Hi MD,

I don't think i'm quite picturing this right. Are you saying there is a male 2" nosepiece on the front of the reducer that goes into the focuser. And then a female 2" nosepiece on the back of the reducer to take camera/eyepieces? If so, i see the problem. Inward travel is tight but will work. But only with the camera connected prime focus as close as possible to the reducer.

The adapter i used was the Antares one that breaks in two to reveal male and female SCT threads, works like a charm with the DSLR:

http://www.scopesnskies.com/prod/antares/astro-camera-adaptor/2inch-sct/camera.html

Russ

[Macavity]

Someone (Thank you!) helpfully pointed me to this little "calculator" recently (my combination required a LOT of in-focus):

http://timosastro.1g.fi/tools/focalreducer.html

Unfortunately I don't know the focal length of the particular reducer here. But maybe someone does...

[moondog]

Thanks for the comments guys.

Rus - that combination looks as if it will definitely give more inward focus. I'll give it a go.

MD

[russ]

MD, it works a treat and is very nicely finished. When the reducer is fitted between the two parts, it all looks like a nice 2" eyepiece. Which then screws into the T-adapter of the camera and plops in the focuser. You'll find it comes to focus with 5mm(ish) to spare.

The only downside is that adapter used to sell for £19.99, so a 50% price hike.

Russ

[moondog]

Rus

I've ordered the adaptor - we'll see if it also works with my CCD camera as this has a T thread fitting.

MD

[centroid]

John, I use the Celestron 6.3 FR with my ED80, without any problem.

The 6.3 has a Focal length of 285mm, so for the ED80, the spacing between the FR and the CCD, needs to be in the order of 60mm.

You can come closer in to the FR than that, but the Foacl Ratio will increase and the FOV will decrease.

Dave

[moondog]

Thanks for that Dave - I've got some T thread spacer rings that I can use to get 60mm for the CCD.

MD