Celestron CG-4 Polar Axis Finder

The instructions for aligning this were terrible. I ended up looking on YouTube and making very, very tiny adjustments on the allen screws. Alignment was a pain. Once you get through with this, the scope works as it should.

Instructions could be a bit more clear - the picture example of centering on a distant object took me a while to realize it was a smoke stack, not some celestial object; everything else was pretty straight forward. I don't understand the hate on the poor positioning you have to get into to look through it - the mount isn't all that tall, you should expect to have to spend a little bit of time sitting on the ground to see through it. The optics are clear, very easy to focus- it would be nice if it were illuminated, but can't complain given the price. This upgrade doubled the effective unguided exposure time on my mount. Very happy overall. Would recommend.

Good quality for the right price. Focus is crisp and etching is easy to see with the help of a dim light. Once installed it aligns to NCP easily and in less than a minute or two. The instructions over simplify the installation by stating to tighten it until it stops - wrong - unless dumb luck is on your side. With the OTA removed, CW shaft in and weights removed, set your latitude to an angle that permits free rotation in RA. Lock your mount so the CW shaft is level vertically, i.e., pointing toward the meridian. Now, screw it in until it stops and check to make sure the cross etching looks like a + and the words are right side up. If this isn't how it appears then tighten or loosen accordingly. Fine tuning the axial alignment is a challenge so take your time. One hundred percent trouble free once installed.

This addition to the Celestron CG-4 mount does the job but is not easy to install or use. I hope you will benefit from my experience. First of all the instructions for mounting are very poor. The instructions are not clear on how to remove the original polar scope holder. You must get a good grip on the end where the adjustment screws stick out and unscrew it counterclockwise. This may be difficult if it is on too tight. Be sure to use the original collar with the degree marks. The one that comes with the polar scope does not have any degree scale. Insert the polar scope and screw until it stops.The instructions for aligning the scope to the RA axis are ok but the process is difficult and takes much fiddling to get it right, but once done you probably will never have to do it again. Now the fun part. They don't tell you that you have to turn yourself into a pretzel to view through the scope once installed. This really needs a right angle eyepiece badly. The installed scope is in the worst possible position to view through but I found a not inexpensive solution. I use the right angle viewfinder attachment that I use on my Pentax DSLR to view through the eyepiece of the polar scope. This makes what is otherwise almost impossible, doable. One of these runs about 20 bucks at mostcamera suppliers. The other fun part I had to figure out was seeing the non-illuminated markings inside the scope in the dark. This features a center circle where Polaris is aligned on and the Big Dipper that you align to by rotating the RA axis. I solved this mystery by using a small diode light in front of and just to the side of the polar scope's objective. This will allow you to see the markings and the stars. So, if you are willing to spend to get a right angle camera viewer, and rig a small light in the front of the scope, this might work for you too. Otherwise, I could not really recommend this without the mods.

It took a good bit of work to figure it out, but once I did, I've had good results. Hint: if you can't get the scope rotated so Cassiopeia matches the pattern in the finder, then turn it exactly opposite Cassiopeia's orientation, and put Polaris opposite the little circle where you'd normally put it. Works with CG-4 mount.

It fits my old CG4 mount (black, not one of the white ones). You can swap out the blank ring on it for the engraved one that comes on the mount. If your manual says you need the 94221 polar scope, this one will fit. You just have to unscrew the original polar scope fitment (as the instructions with this scope show).

Absolutely essential for astro-photography using the CG-4. Unfortunately this is the only option for this mount.. Collimating it is a bit of a chore, and you can only get it to work so far. I managed to pull 2 minutes exposure with very minimal trails (good enough for deep sky stacker to work), but that required a whole lot of attention. 30 seconds exposures are much easier to get.Pros:- Good engravings on the reticle.- The only option for CG-4- If you are careful, you can get quite good polar alignments with itCons:- It comes with an empty dial. If you want to use DEC/RA to find objects you have to manually replace the dial. (However, the whole CG-4 is not really the best for DEC/RA locating..)- Collimating it is a bit of a task, but once you get it its pretty much done- Hard to see the reticle engravings at night. Have to mess around with a red flash-light until they become visible.The best and only option for polar aligning a CG-4 mount. If you are thinking about going into astro-photography I would recommend looking for a more advanced mount.

Great service,fit great in cg-4 mount.Seems to be well built.