You will use a barlow-type relay lens with a binoviewer that will essentially double the f/ratio of the scope, so the edge-of field images will improve. They...
Don: Appreciate your anwswer. Yes, I have heard of some viewers using a barlow lens to get enough in-focus. I've heard that a barlow- type lens is used to...
... The extra focal distance added by the length of the binoviewer is what requires the extra in-focusing--too much, in fact, to come to focus in the scope....
Thank you, Don: You have given me the best explanation I have heard on the f-ratio/eyepieces/binoviewer subject. Now, that makes sense. The barlow/relay...
I'm in Nebraska, and its been impossible to see it here too. The sun just goes down and then its too bright yet for stars, much less a dim comet group. I've...
I am trying to sell an older 12.5" for $800. Includes Discovery digital setting circles, other accessories, primary mirror test result file from Riverside...
Just wondering if anyone has yet taken delivery on a 20 inch or larger discovery scope (truss or tube). Since they advertise them I was interested in hearing...
This will be a testimonial for a non-Discovery product but it really adds to the enjoyment of my PDHQ so I thought it'd be appropriate to share here. Like many...
Chris, I took delivery of a 20" f5 truss last fall. It is a very good scope. I'm not an optician but to my eyes the optics are very good. It star tests...
Chris, I'm using a Discovery 24", f/4.5 primary mirror in my home-built Truss Dob. The images are stunning. I still have my original 17.5 TD--- another great...
Hello group, I'm considering installing the ServoCAT motors on my Discovery 17.5 TD - has anybody in the group done this ? I've already looked at the dvd from...
Hello Angelo, If you look at the Servocat Jr webpage, there are a couple of photos of my 15" TD that Gary installed. What he did was remove the side bearings...
Angelo, I have a Discovery 17.5" TD dob with a ServoCAT and as was pointed out in an earlier email, you need to rotate the alt bearings in order to install the...
I got in on that May sale at the 11th hour yesterday. I just couldn't resist the discount offered. I've been meaning to pickup a dob and that just sent me over...
Hi Chris, Congratulations! Once you receive your scope you'll probably want to "tweak" things to suit your needs and this group has a lot of experience with...
This will be my first reflector of any kind so I'm completely clueless on this matter. What do you all use to collimate your scopes? I was looking specifically...
I use the orion Cheshire combination eyepiece/sight tube. It's very simple and accurate. I got turned off of the laser collimators when I started reading...
... I'm firmly in the laser camp. I cannot get myself organized to get to the observing site before it starts getting dark, which makes it much more...
... clueless ... to ... Chris, Here is Mel Bartel's web site for collimation. http://www.oarval.org/collimatE.htm It's a very good site in that it gives you...
Chris, Put me down as firmly in the "Non-laser" camp. With the exception of Glatter lasers, the odds are high you will have to collimate your laser right out...
Star-gazing on a work night this time of year is somewhat pointless at my latitude of approx. 46* N. (unless you're viewing a planet or the moon). It still...
Hi Don, I'm assuming you use or have used the Cat's Eye tools? The Cat's Eye system will be my collimation tools of choice I think. On his site he mentions...
Chris, 1. I use the 2" Catseye tools. They are easier to use than the 1-1/4" versions, and since Nearly all my eyepieces are 2", it made sense. 2.The center...
Just a heads up... After having the vinyl dustcap on the primary mirror end of my split tube for a couple of months, when I removed it , a couple of chunks of...
My dust caps (the black shower cap type) are on for two or three weeks at a time and have not been a problem. My tube is covered in something like Monokote, a...
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