polar alignment

[wolfdogg]

whats the best way to polar align with a celestron fork mounted c8 wedge? its exactly like this one here at ebayhttp://www.ebay.com/itm/CELESTRON-C8-EQUATORIAL-ADJUSTABLE-TELESCOPE-WEDGE-/220802628544 but not that dirty :-) but this one pictured is missing the 2 T-handles, and the 3 bolts, mines fully in tact. For those who arent exactly familiar, the t handles screw into the front edge of the base (right side of picture 1), and teh 3 bolts go into the 3 slotted holes that are visible on the top of the base. the middle hole on the base is unused.

I have really never been shown how to do this, i can only tell how i do it, and see if theres anything i can do better.

what i usually do is

snug up the 3 bolts just enough so i can still twist the T-handles to make the scope move, i think that part is obvious.

set both t-handles near center

set the dec. as close as i can get to 90deg on the fork guage (this might be anywhere from .25 to 2 degrees off, depending if the guage is accurate, and its rounded to nearest degree)

take er' outside

level up the tripod/wedge base with a bubble level (my cell phone works for this now-a-days, cool)

then i hone in on polaris, but of course if the wedge is off, i have to bring out the ratchet and painstakingly adjust the wedge (a terrible curse of a job to hang on to the scope and get it pin pointed on the dec. being at 30 some odd degrees latitude)

and as i go, i turn the t handles to adjust the RA each step of the way, since thats the easiest part.

rinse and repeat, until polaris is central in the eyepiece, adn in the crosshairs of finder scope

then i spin the scope on its RA axis while watching in the eyepiece to make sure there little if no wobble (if there is, im guessing its the Dec. guage or lack of a better one)

thats it.

is there an easier way, is my mount absurd? or should i get a new mount that has a dec. adjuster bolt on it?

edit.. hmm, there IS an adjuster bolt on that one on picture 7 of the item, mine doesnt have that.. im missing that entire adjusted bracket that the adjuster bolt is threaded into, it looks like its an addon part, or something. other than that, the mount looks exact. But the pictured mount still show the t-handle holes, I think its without, funny, because you shoudl be able to see the holes in the 3rd picture.

[barkis]

That wedge looks quite primitive, and wedges normally have mechanisms to allow fine adjustments in Azimuth, and elevation, whereby you don't have feel the scope is going to fall on you when you release the bolt tensions.

If you are just an observer, the polar alignment accuracy isn't a critical requiremnent, so I wouldn't fight with it too much.

If you intend imaging with your setup, perhaps you could consider buying an HEQ5 Pro mount, and fit your C8 OTA to that.

Ron.

[wolfdogg]

thanks, ill look into that, i was hoping somebody would say "replace that old thing" lol.

Is my alignment procedure atleast correct for my current setup?

For teh HEQ5 Pro, are you suggesting this mount for 2 reasons? Ease of polar alignment, and for photography? It looks a bit expensive, and im not used to something so cumbersome. Does it add alot of weight to hand carry the already heavy scope when fully mounted? Dont worry im a tough 6' 1" man, but im not sure how much the counterweights add to the entire weight.

i have a t-ring for my EOS 35mm still cam (SLR), but its too expensive for film development, and have been planning and having a hard time getting a nice DSLR for years. I almost got a Nikon D series DSLR this christmas from my wife, but they were out of stock from the company that was going to finance it. Doh!!

So no photography currently, but definitely in the future ill resume photography. I have not tried my hand with an off-axis-guider either for long exposures. I have just done solar, lunar, planetary and terrestrial. So that makes for 4 pieces of equipment that i will need before i can get some nice DS shots. New mount, Focal reducer, Off Axis Guider and a Camera... OUCH! Thats not going to be cheap.

[barkis]

Second hand HEQ5 mounts can be found occasionally, which are reasonably priced, but that aside, imaging can become an expensive part of astronomy, so I understand where you're coming from.

You can persevere with your existing wedge of course. I notice in one of the pics in the link you provided, there is a fine tuning screw for making incremental to the elevation of the wedge.

If that is included on your mount, then I would replace it with a High tensile hexagon headed bolt. A screwdriver wouldn't be easy to turn with the scope in situ.

If I was you, I would make the polar adjustments with the OTA off the mount. You can put a small bore sight tube into the location slot on the base where the OTA sits. Make sure it is at a perfect right angle to the base. Then simply move the mount in Azimuth and elevation, until Polaris can be seen through the sight tube.

The smaller the hole in the tube, the better.

Once you succeed in getting the star lined up, securely tighten all the bolts holding the mount in place, the re attach the OTA.

That should permit good tracking for observational purposes.

You might even get some short subs on the Orion Neb. 20 second shots each one, then stack them. If they are OK increase the sub duration to 30 secs. You might be surprised at the result.

The Orion Nebula is quite near the celestial equator, so any trailing will be more pronounced.

Object imaged at a higher declination, will show shorter trails. Adjust your exposure times until there is no pronounced trailing.Good Luck anyway.

Ron.

Edit:

Sorry, I've read your post again, and your mount doesn't have the vernier bolt. However, the procedure I've described, will be fairly easy to accomplish with your OTA off the mount.