So i'm a bit of a planetary bloke thanks to the poor seeing conditions in this major city, ever since.... forever. Long time observer.
Been a while since I logged in! Maybe decades! Surprised I rem-embered the account! Also the site looks the same! Wow!
Im in Melb.. and BRRRRR, it is cold! With fond memories of perfect seeing of Jupiter perfect before sunrise I wheeled the dobby out!
1stly, Juptier has changed man. GRS is now red, quite unlike my 2015 obserations, last time I drew it. I sketch. Another thing. In 2015 the 'subtropical-demarcation(?)' (equatorial) bands were doubled up. Now they are singular!?
Also, saw Mercury, pretty shakey but i'll warrant there was some detail. Also sketched three prominent clouds on Venus! Score! One polar. One subtropical. One equatorial, coming off the sunrise plane.
I could really see the tree-like blood vessels in my eyes at 158x is this common? That was putting me off!
Caught some clouds on venus. Bit of swell there. Threw in the red filter, wow... not sure filters do that much honestly except the blue clouds of Mars.
Someone explain this. I have viewed thru telrad, (member of the club), and found it's like looking at the sky. So here is my gripe!
I look thru the normal refractor finder one eye. One eye on the sky, and bring em together. The brain computes this in .00002 seconds, so... what's the telrad for?
Is the telrad for guys re-incarnated from ww1 fighter pilots who want a gunsight on their scope?
I have a phd but i'm a bit of a 'jock' so, you're gonna have to explain VERY slowly for this early bird who is not a nurd. Cheers! I mean that in the best possible way!
For us looneys who use their telescopes for taking images with an equatorial mount when we first setup, we need to do a first star alignment.
So we would command the mount to goto an alignment star and if it doesn't appear in the FOV of the camera, we use the Telrad to get that star into the inner circle by using the mounts RA/DEC controls. When the star is in the inner circle of the Telrad it will also apppear in the FOV of the camera, which we can then fine tune to centre the star in the frame and press the Enter key for the mount so it now knows where it is pointing..
That's about it, once the mount knows where it is pointing we don't really need the Telrad anymore.
These days with Plate solving software the Telrad is redundant, just point the mount to a random piece of sky, take a 10sec image, plate solve that image which returns the centre RA/DEC address and sync the mount to that address.
P.S. I don't remember seeing blood vessels when viewing but I did have a lot of floaters which is annoying.
Interesting. So it's just for polar alignment? I seen some peeps with it on their dobby which confused the heck out of me wondering what it could be for!
I can see how it would be VERY useful for polar alignment. WOW! Didn't think of that but I've never aligned a polar scope.
Yeah I only saw the blood vessels on Jupiter and can't remember ever seeing them before. Apparently it's an explanation for the canals on Mars, but that is BS cos the vessels move around while the features on the planet stay still. The local astronomy club mag even showed a Hubble shot with the Lowellian markings on venus clearly visible and remarked at this. Cheers.
Its used on dobs to aid visual pointing and especially larger dobs where it is mounted on the cage , its good because you dont need to look directly into it like a finderscope you can sight along the tube at a distance making it much easier point.
When aligned properly, a red dot finder (RDF) of which the Telrad is just a fancy version, attached to a dob, is the absolute quickest way to aim at a target that is visible naked-eye (like a planet). Paired with some star hopping skills, it's also a great tool for finding DSOs not seen naked-eye but easily visible through the scope.
If you have a right angled, erect image finderscope, then you need a Telrad or some type of red dot finder.
With a straight through finder, I can often make do without a red dot finder when using a 6X30 finder, though I find it much tougher going trying to use a straight through 8X50 because of the narrower field.
I once met a sharp-eyed chap who only had a Telrad on his big dob - he said he didn't need a finderscope.
Also, for us people without as good a vision as that chap - one can put one barrel of a pair of binoculars behind the Telrad, and use that as a finderscope.
Regards,
Renato
When aligned properly, a red dot finder (RDF) of which the Telrad is just a fancy version, attached to a dob, is the absolute quickest way to aim at a target that is visible naked-eye (like a planet). Paired with some star hopping skills, it's also a great tool for finding DSOs not seen naked-eye but easily visible through the scope.
1) People use the Telrad for different purposes, which I did not expect.
2) When I buy my SDM or Obsession I shall use a telrad, possibly, or just GOTO. (First going to coat garage floor in polyurethane)
3) I may also use it for astro if I buy a polar align scope! Hmmm! I don't see myself using a right-angle finder, to me that isn't a finder at all! More like a 'hider'.
Thanks guys!
Feel free to keep going!
Another thing not covered. I've seen telrads on small dobs! That's what kicked this thread off in the first place, I assumed people put one on any scope willy nilly but didn't know the reason. Also I've been an amateur for ages, by binoculars and dob since 2002 and can find anything pretty easy.
In the days before go to mounts, and electronic star maps, the telrad was a useful tool for finding stuff, not just for pointing the scope at a spot, as in a rdf.. the rings of the telrad show .5, 2 and 4 degree circles. When a known star is found, the position of a desired target can be located by ‘Star hopping’ to other stars along the way. Utilising a star chart, one can locate intermediate stars and their distance from each of the others along the way, noting their separation in degrees. The telrad allows one to try to identify these intermediate stars using the rings as a guide to their angular separation. Having found an intermediate star, it can be centred in the scope, and then using the telrad, locate the subsequent stars until eventually getting to the desired target.
These days, with go to mounts, Argo Navis , and electronic charts, the telrad is slow and cumbersome. Like moving from log tables to a scientific calculator.
Some however, enjoy the search without the aid of electronics.
I look thru the normal refractor finder one eye. One eye on the sky, and bring em together. The brain computes this in .00002 seconds, so... what's the telrad for?
Don’t suppose it has ever occurred to you that some are not blessed with perfect vision, or that some of us have scopes whth far smaller fields of view ?
I am one who cannot do what you describe, and yes I need a WWII gunsight, of some sort.
Secondly my scope has a max field of view at its lowest power less than the moons diameter. Locating targets with it is non trivial - even after 45 years.
I use mine for star hopping. It would have to be the best unit finder out there in my opinion. Teamed with a decent star atlas( one which has a Telrad reticule plastic overlay) it makes finding objects simple.
Agreed , these are the best by far in use but , you have to remember to turn it off when not in use as they flatten the batteries fairly quickly .
Hence I made a quick and dirty cover so that the switch has to be in the off position to fit .
Brian.
Quote:
Originally Posted by GUS.K
I use mine for star hopping. It would have to be the best unit finder out there in my opinion. Teamed with a decent star atlas( one which has a Telrad reticule plastic overlay) it makes finding objects simple.
I think a Telrad is the best finder addition to a scope ever developed. I don’t really use the finder if the telrad is on. The fact that it is still in production pretty much unchanged says it all really. The batteries lasts days or weeks, even if left on. Axis Alignment is always good , easy and robust, unlike the fiddly finder scope (unless you are using a Tak type quality) there is less chance of bumping the scope.
Particularly for any large diameter scope where the sky is obscured by the tube and has a long focal length. . I can very quickly see exactly where the scope is pointing and swing or guide to an object very quickly without using glasses.
Perfect for star alignment , to get an object located in a camera , eyepiece or to see if the horizon is creeping up.
Looks just like Stellarium with no need for glasses for me and a better view of the sky.
3) I may also use it for astro if I buy a polar align scope! Hmmm! I don't see myself using a right-angle finder, to me that isn't a finder at all! More like a 'hider'.
Thanks guys!
Feel free to keep going!
There is NOTHING easier to use on a manual telescope than a Telrad/Red Dot finder coupled with an Right Angled Correct Image Finderscope. I have that set up on my 14.5" dob, on my 8"SCT, on my 5" Mak and last night used it for the first time on my 4" achromat.
A Right Angled Erect Image Finder (with mirror image view) is indeed pretty useless for me.
At 4am this morning I was using my Celestron 4" Achromat f/5 mounted on a Celestron/Vixen slow motion control, sitting on top of a camera tripod, aiming nearly directly overhead. Using the red dot finder plus the 6X30 Right angled Correct Image finder - it was simple picking off Messier Objects. I know it would have been a very painful exercise trying to use a 6X30 straight-through finder to do the same thing, which was the reason I replaced it the other day with the Correct image finder.
Regards,
Renato
That was putting me off! 
you have to remember to turn it off when not in use as they flatten the batteries fairly quickly . 
