Posts Made By: rushby craig

Here are two images from last night (Feb 16) and this morning (Feb 17)using my DGM Optics OA-3.6 off-axis newtonian and a Celestron Neximage camera @ f22. Not as nice as some of you guys who have more experience, as well as larger aperature and focal length to work with, but OK for a beginner perhaps.

Here is my second attempt at imaging saturn. It turned out much better this try. This time at f30 with my DGM Optics 3.6" off-axis newt and a Neximage camera (600 frames). I enlarged the picture 150% in Registax. I just received my new Televue 3X barlow today, and needed to try it out. The seeing seems much better here in suburban Salt Lake City than usual.

Question for you Resgistax users-- Do you all have the same problem running Registax that I do?

I notice that when I have less than say 600 frames captured, my laptop goes through the image processing steps very quickly--say a minute or two. When I have more than that (I've tried staking and processing up to 1200), all of the sudden the machine gets so slow that I can hardly stand to deal with it. It might take me 2-3 hours to go through the steps. Sometimes it will crash in the middle of that 2-3 hour period. Could there be something in my settings that is causing this? My machine is a new pentium 4, 1.7 GHz, 1 GB RAM. I don't think that there is a lack of computing power.

Rushby

Hi Roland,

I'd be interested in your take on something. I see that you sometimes drop in on this forum.

I've got a project going on right now to build a newtonian reflector. I'm using an aluminum tube, and will be using some computer fans to pull air out the back of the mirror cell.

I've read lots of discussion on these forums (and other places) with opinions on the best ways to finish aluminum tubes in order to manage heat. I know that there are several issues to deal with such as: radiation of heat to the outside of the tube, the inside of the tube & optics, formation of dew etc. I'm sure that whatever design choice is made will have some trade-offs.

Some propose leaving the tube bare aluminum on the outside, and using an insulating material on the inside (such as cork or flocking paper). I read one article proposing that it is best to paint the tube black on the outside, and white on the inside first before coating with flat black.

I've seen you make some comments on thermal management before. And you obviously know the subject well. Just observing, I see that you use white paint on the exterior of your tubes.

If you were going to build a newtonian in an aluminum tube (and I realize that is probably a real stretch), how would you finish the tube?

Interested in some opinions...
I am building an 8" f6 newt that I want to equatorially mount. The weight of the tube will likely be in the 15-16 pound range. I have a super polaris mount on a wooden tripod currently (with dual axis drives). This configuration will probably be a bit wobbly for the mount, I would think. Do you think that I would be able to get satisfactory performance from this mount and scope combo if I upgraded to a metal pier?

Some very nice images by Alan and Jim from last night/this morning. I was also out fiddling with my new 8" f/6 newt and took the following image with my NexImage camera. Any tips from the pro's on how to improve? I used 10 fps, and collected about 60 seconds of video. Also, I was using a 3X Televue Barlow to get to f/18. Additionally, I have a question...I tried to stack 2x and 3x Televue barlows, but found that the two don't stack well (I think) because the tube of the 2x (which is shorter than the 3x) doesn't seat down all of the way into the 3x--there isn't enough depth in the 3x. Is that a problem? Or does that just affect the multiplication factor of the combo?

I have a reflector that I use on a Synta EQ6 Synscan GEM. The combo works pretty well, but there's one thing about it that bugs me. Apparently the optical axis of the scope is not parallel with the tube. When I do an alignment of the mount with 3 stars, the go-to works fine--but when I need to rotate the tube to put the eyepiece at a comfortable angle, the image in the eyepiece moves along with it. Then I have to hunt around to find the object again, and sometimes that is not so easy.

I was pretty careful when I built the scope to make sure that the primary and secondary were reasonably centered in the tube. Can the fact that I didn't offset the secondary away from the focuser make that much of a difference in where the optical axis is pointing?

Anybody else solved this problem before?

I was expecting to hear news from NEAF about new AP Mak models to be produced. It seemed from some of the forum posts Roland made, that he was intimating as much.

I know that there are a lot of people using these mounts out there...

A trio of topics for those of you who do.

I notice with my EQ-6 that the Go-To accuracy on planets is not very good. It usually gets in the general area, but is off by a bit. That is not a problem for the brighter planets, but I tried a few times to find Uranus and Neptune and have never been successful. Has anyone else out there has this experience? IT baffles me a little, because the accuracy seems much better on deep-sky objects. I don't have the newest version of the controller and software. The mount is a couple of years old.

Second...When I polar align, i find that I'm not able to align the OTA on Polaris, it is off a little. I've never worried too much about it, but is this something that I should adjust for?

Third...There are three allen screws that tighten down the dovetail mounting area on the end of the declination axis (at 120 degree intervals). These seem to come loose frequently, and I have to re-tighten so that the OTA doesn't start slipping and rotating on its own. Anybody else have this irritating problem, and found a way to solve it?

I know that there are a lot of people using these mounts out there...

A trio of topics for those of you who do.

I notice with my EQ-6 that the Go-To accuracy on planets is not very good. It usually gets in the general area, but is off by a bit. That is not a problem for the brighter planets, but I tried a few times to find Uranus and Neptune and have never been successful. Has anyone else out there has this experience? IT baffles me a little, because the accuracy seems much better on deep-sky objects. I don't have the newest version of the controller and software. The mount is a couple of years old.

Second...When I polar align, i find that I'm not able to align the OTA on Polaris, it is off a little. I've never worried too much about it, but is this something that I should adjust for?

Third...There are three allen screws that tighten down the dovetail mounting area on the end of the declination axis (at 120 degree intervals). These seem to come loose frequently, and I have to re-tighten so that the OTA doesn't start slipping and rotating on its own. Anybody else have this irritating problem, and found a way to solve it?

I have a collection of eyepieces that are mostly Plossls at the longer focal lengths (32mm, 26mm, 15mm) and a 7mm Nagler and 5mm Radian at the shorter focal lengths.

I've had a Tak Fs-128 refractor (f/8.1) for about a year now, and am thinking about adding some Televue Naglers, Panoptics at the lower focal lengths. If some of you have the same or similar scope, I'd be interested in what you think would be a good set of low power eyepieces to go with this scope. My second scope is an 8" f/6 dob that I built--so the focal length is slightly longer but similar. I've read great things about a 31mm Nagler or 35mm Panoptic with the Tak. What about a 20mm Nagler as a companion? Other suggestions?