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Posts Made By: Rod Mollise

October 5, 2013 06:43 AM Forum: Equipment Talk

Sidereal Tracking on a 1980's C8

Posted By Rod Mollise

Ken Hansen said:

Apparently there are no more of those Accutrack controllers to be had.

I had donated my C8 to a private school several years ago. The school closed down and I got it back. It had some problems. That oval power receptacle in the base must have broke because some one kluged a power cord onto it. I managed to get a receptacle on it to work and can now hook it up to an AC outlet and it runs.

The "Accutrack" controller appears to be be non functional. The fuse is not blown. I don't have much in the way of diagnostic equipment to see what's wrong with it.

Does anyone know of a way to get the C8 to run on a sidereal (or lunar, or whatever) clock without one of those controllers?

Thanks

Ken H
Marion, IA

It will track at sidereal rate when you plug it in. As for the drive controller...see if you can find an electronically knowledgeable person--like a local ham--to look at it. It is a simple device.

October 9, 2013 04:25 PM Forum: Comets

October 9, 2013 04:30 PM Forum: Mounts

mount tracking accuracy

Posted By Rod Mollise

Paul Benoit said:

Hello all,
I want to get myself into astrophotography. Before spending a fortune on equipment, I want to confirm this new hobby using my existing photo equipment (my longest lens is 600 4, which I can push to 1200mm) and am planning to buy a second hand Canon 60d I could have modified to let the H alpha through.
Now comes the question of the mount. Provided the fairly short focal lengths I am planning on using (for now), I was wondering about the type of mount I should consider acquiring for clean pinpoint stars on up to 15min PEC corrected and-or guided mount shot exposures. I can see a group of mounts (EQ6, CGEM DX, iEQ45, G11, Vixen SXD) in the 1500-2500$ price range that I would be happy to invest in if they are providing good enough tracking accuracy. Now should I consider going one step up and look at more accurate models such as an EQ8, AP Mac1GTO, 10Micron 1000HGS, Bisque Paramount MX, ASA DMM60 or the like, but then we are really not talking about the same budget.
Advise from forum experts much appreciated. Thank you. Paul.

The long and the short of it? At 600mm, any of these mounts will give you a minute or so with a good proportion of acceptable frames. Want more than that? You will need to guide. If you guide, any of these mounts will do what you want. One suggestion? You will find that at these focal lengths a small telescope like an ED refractor designed for astronomy will yield better results and will be easier to frame. Also, if you plan on sticking with a DSLR and a long lens, you might look at iOptrons Ieq25 mount.

Finally, get started simply with a normal lens before you start upping the focal length. At 1200mm, especially, things get HARDER. wink

September 29, 2014 12:21 PM Forum: Equipment Talk

CGEM DX w/Sky-Watcher Skymax 150 Pro = Astrophotog

Posted By Rod Mollise

Michael Teer said:

Greetings! Newb here, looking to build my first astrophotography scope. I started with buying a used CGEM DX mount, which I will likely send off for a Hypertune.

I still need a tripod and OTA. I had my heart set on a 100-130mm APO triplet refractor, with aspirations of going to 150-180mm using the same mount/tripod down the road.

But the $3k-$5k price is hard to pony up to, and I saw this scope for sale on EBay stating "APO-like" quality with pictures includee in the listing taken with the scope, which looked ok to me.

http://m.ebay.com/itm/201176542507

My question is, would this be a good jumping on point for an OTA, while I put away for the refractor I desire? I plan on using my Canon T3i camera using prime focus.

Just looking for veteran feedback. Thanks in advance for any opinions/expertise.

Michael

Hokay...first off, why are you buying a CGEM DX, and looking for another tripod for it? The tripod that _comes_ with the CGEM DX is the main reason for buying it and the major thing that makes it different from the standard CGEM.

As for the scope? This is a good choice for imaging the Moon and planets. The deep sky, stars, galaxies, nebulae? Not so much.

'Twere me, I'd look at an 80 - 100mm ED/APO refractor.

Also, if you think you just have to send the mount off to be "hypertuned" (most people would tell you that is not necessary unless it has problems), you should look at a different mount. Depending on the scope you choose, an Orion Sirius or Atlas might be a better choice for you.


September 29, 2014 02:07 PM Forum: Equipment Talk

Restoration/upgrade from MEADE MTS-SC8

Posted By Rod Mollise

As long as the primary coatings are in good shape, the scope is likely a go (it's reasonably easy to have the secondary recoated if necessary). Unless the scope was stored in a damp area, I'm guessing not much may be needed beyond cleaning the corrector.

Nor is it a big job to get this on a goto mount. A Celestron VX, a Vixen style dovetail for the scope, and you are ready to go. Removing a few screws will allow you to remove the OTA from the fork.

A 2-inch SCT back or 2-inch diagonal is a common item and will work on this scope.

The primary difference between the MTS and current standard SCTs will be the coatings. Those on modern scopes are more reflective. But this scope will likely perform well with just a simple cleaning and maybe a few other tuneups. wink

October 1, 2014 08:13 AM Forum: Refractors

Re: 102 vs 102 ED

Posted By Rod Mollise

Let me add that I had the C102 out looking at the Moon, a nice, bright crescent, last night. Yes, there was some color. A thin purple-blue line on the limb, and a slight purplish tinge to shadows at some magnifications. The image was basically spectacular despite the Moon's relatively low altitude this time of year. At 300x, I was seeing plenty of Cool Stuff. wink

October 9, 2014 03:32 PM Forum: Beginning Astronomy?

fast scopes and planetary viewing

Posted By Rod Mollise

Joe Sgambellone said:

Hi - I have a 10" Newtonian dob (f/4.5). I've been reading that slower scopes (> f/6) are better for viewing solar system objects. I haven't found an explanation for this. Can someone explain this to me or point me somewhere where I can read about it, preferably written so that a 5-year-old can understand it. grin

Thanks!
Joe

The main reason? It's easier to get higher magnification for planetary work with longer more comfortable to use eyepiece focal lengths.

OTOH, you can just use a barlow with an eyepiece on a faster scope.

Some people thing that slower mirrors are easier to make very well. The opposite is actually the case. wink

October 31, 2014 09:41 AM Forum: Deep Sky Observing

NGC 7094: A Challenge Object

Posted By Rod Mollise

I've seen it with a 12 under good conditions...but not easy. It seems to me I found a UHC worked a little better than an OIII on this one for me.

November 1, 2014 11:15 AM Forum: Equipment Talk

Screws for a telescope finder scope

Posted By Rod Mollise

A good place to start is always scopestuff.com wink

November 2, 2014 01:09 PM Forum: Telescope Making

Mirror Testing

Posted By Rod Mollise

Thomas Northup said:

A friend of mine recently acquired a 32" mirror, 2" thick and a FL of 147".
He is wondering if there is a place he can have this mirror tested.
Any suggestions?
Thanks
Tom

Depends on the "why". Do you suspect it has a problem? Or do you just want a quick read on its quality? As another poster mentioned, a quick run with a Foucault tester is a lot easier than shipping this big primary off, especially if there is nothing wrong with it. If you can put it in a scope for a star test, even better.