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Old 23-09-2018, 03:28 PM
Legin (Nigel)
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Legin is offline
Join Date: Jul 2008
Location: Sydney
Posts: 76
Focuser 9.25" Edge HD


Ok so I have taken a bit of a plunge and obtained a 9.25" Edge telescope. I currently have it on an AZ NEQ6 GT mount. I use a few cameras but mostly use either the ASI 174MC or the trusty ASI120MM.

This is pretty good scope for visual work and I rarely have any trouble focusing. At least it looks good visually.

I am trying to take some images of the planets and Moon. At prim focus I can almost get focus right. I zoom in with Sharpcap to 200% and focus the best I can then go back to 100%. Then I cut the size down to something like 900x900 pixels (can not remember the exact number). Then I take a short video usually 30-50 seconds or so.

The problem I have is that when I try to get closer in using any kind of barlow I find it near impossible to obtain perfect focus. I usually use a 3x barlow. If the seeing is really good I wish to go for a 4 x barlow and vice versa bad seeing I will use 2x if any.

At higher magnification I usually do a similar thing I zoom in to something like 150-200% and try to focus as best I can. This is difficult to do as it is effectively bringing the magnification way higher. But If I get the best I can at this % I figure it should be perfect at 100%.

Then I repeat the process cropping down the image size and capturing a short avi of 30-50 seconds.

The focus never seems to be quite right.

I have a few questions. As it is the scope will focus by moving the primary mirror. This leads to a significant image movement. This really makes it hard to focus at high power as the image often jumps out of frame and I need to move the scope.

As such I am thinking of obtaining an external focuser. What do you recommend. I am happy to pay a bit extra to get a good focuser as I believe it will be well worth it. Messing around with bad focusers is frustrating to say the least.

On another note I currently have two 5kg counter weights on the scop but even at the most distance from the mount still seems a bit heavy on the scope side. Could I put another 5kg counterweight on this mount. I am a bit worried that I am approaching the max weight. It seems within the specs as the mount can handle up to 22kg or so without any problems and I think the scope is around 13-14kg. Would the counterweight cause problems. I think it is bordering on the slightly heavy side but it should be ok.

Any help you can provide will be appreciated...
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