Celestron NexGuide, Autoguider Perfect for Imaging with Your DSLR Camera, Black (93713)

I have to say that I almost thought of returning NexGuide after two initial nights of frustration.First of all, the manual is not the greatest in explaining how to get started or how to troubleshoot main issue that happened to me which is not obtaining a guide star.Then, I did some research, including on Cloudy Nights, to figure out if the unit was defective or just that difficult to use or maybe I was doing something wrong.Let me tell you this, obtaining the right focus is crucial. However, it is not as easy as it seems.Manual says to use par-focal eyepiece, which I do not have, then it is talking about starting with exposure time of 200 and playing with noise levels.Well, this really all depends on where you are located (light pollution) and your guiderscope.I finally got it right on the third night and then tried again and was able to obtain guiding star pretty easy.My setup is as follows: Celestron AVX mount (German Equatorial), Explore Scientific AR150 doublet with right angle finderscope, Solomark F60 60mm Guidescope 215mm Focal Length, F/3.6 Focal Ratio, Fully Coated w/ Helical Focuser, Celestron 93230 8 to 24mm 1.25 Zoom Eyepiece, green laser pointer. Power from Suaoki 400Wh Portable Solar Generator Power Supply.So here is what I did to finally get this thing to work.First off set up and Polar align the mount. On my AVX this means, level, point to north, wait for polar star, shine green laser through polar axis hole, then remove laser and look if I can see Polaris through the hole.Then do two-star alignment, add 3 to 4 calibrating stars and then do Polar alignment adjusting Azimuth and Latitude knobs.With this setup I can do up to 1.5 minute exposures with no or minimal drifting. After 1.5 minutes stars drift visibly.Now to the NexGuide setup.I mounted guiderscope on the top of ES AR150 handle which is parallel to the dovetail bar, parallel to the mounting shoe of the mount.To get it working for the first time I found a bright star, pointed the telescope to that star and then inserted Celestron zoom piece in the guiderscope and set it to 24mm.Solomark guiderscope has both sliding and helical focus.First I slide and lock the sliding focus piece to get close to focus on anything I can see in the eyepiece. Then, I lock the sliding piece and use helical focuser to fine tune the focus.After that, I move the scope and make the star I chose in the middle of my 24mm eyepiece in guiderscope. Then, I zoom in the eyepiece and keep on adjusting the mount to keep the star in the center. Finally when I get to 8mm and star in the center of guiderscope I lock the helical focus.Then I remove the eyepiece and replace with NexGuide attach guiding cable to my mount and hand control as well as 12v cable.I make sure that the NexGuide is mounted parallel to the mount declination axis, scope and guoiderscope.When NexGuide is on it goes by default to Preview mode. In my light polluted skies I had to adjust exposure time to 100 and at one point to 70.Then I unlock the helical focus and adjust to get the star show on the display with a square showing around it. Sometimes I have to adjust the sliding focus as well.Once the star is shown and stable (which means NexGuide is not jumping squares around display) I switch to the Lock Menu and switch on Auto Lock.When locked the NexGuide zooms in on the star and then I unlock helical focus and fine tune it to make the dot the smallest possible in zoom mode.You have to be careful because at the zoom NexGuide defaults to it is easy to introduce vibrations that temporarily move the alignment star out of the LCD display.If this happens I reduce the zoom to adjust focus.Then I switch to Guide Menu and choose Auto Cal. After calibration when NexGuide moves the mount horizontally and vertically a bit NexGuide is guiding.Finally a success.Now, since I have the sliding focus and helical focus locked in focus mode I can stop guiding and move to where I actually want to auto guide.When I move to other objects I always have to slightly adjust focus, mainly with helical fine focusing.One thing I noticed is how useful my zoom eyepiece became for setting up the mount and guiderscope.Now I wish someone made 8-24 zoom eyepiece with illuminated reticle. This would come very handy.So far I have tried this on Orion Nebula and Pleiades, both from my light polluted backyard.I have guided so far up to 5 minutes with no star trails whatsoever.I have not guided longer as light pollution causes over exposure on my Canon 5D Mark II.I have not tried fainter objects yet but many of them I can see problems with in my light polluted backyard.As I mentioned before, with very good Polar Alignment I could guide maximum to minute and a half at most with no autoguider.Therefore, 5 minutes is pretty good in my book.I will try to test the maximum guiding time soon.Here are the things for which I am deducting 1 star:- Display is not that visible and can be at awkward angles on German Equatorial mount. I could definitely use a bigger display.- Guiding cable not very long. Have to be careful when slewing.- I would prefer ports on the side rather than bottom.- Manual is not very well written especially when it comes to troubleshooting and initial setup.- There is USB port on NexGuide but manual does not mention what is the use for it, other that it is there. I know this is not the tool for dummies but come on, give me a break and put something in the manual.What also could be improved in the future to make it almost perfect:- Better and bigger display.- Battery powered wireless hand control with 12v plug option but not attached to the NexGuide.- Wireless guiding via SkyQLink.Hope this review helps.

Works very well. As many times I've tried, I was always able to find a star. Can do 10 minutes exposures without problems with nexguide on and 80mm Celstron guide scope. Considering my scope is 8" SCT with over 2000 mm focal length and Nexguide is able to guide the whole thing for 10 minutes, is quite amazing. I don't have to deal with cables. I use Full Spectrum Modified DSLR and Nexguide for guiding. Its called - FREEDOM. No cables, no hassle. No matter all the bad reviews I am glad I bought NexGuide Autogider. It literally takes me about 2-3 minutes to get the guiding going as soon as I find a star and so far I didn't have a problem of finding one bright enough for NexGuide to detect it. With the number of options that you can customize you can get it to guide on very faint stars. I think bad reviews come from people with badly light polluted sky or with weak guide scopes. As long as you can see some stars through your guider scope - this thing will provide you with hours of comfort and unattended guiding.

The manual is minimal. It works with bright stars, but the sensitivity is so poor that you'll waste a lot of time trying to find a star bright enough to use. The only thing good about it is that you don't need an external computer. There is no option for external power either, so you have the battery pack to worry with. A much better solution is the Orion guider with a small notebook computer.

Although it may be nice to be able to autoguide without a computer, this particular unit doesn't deliver.It doesn't support sub-pixel guiding so guiding is very coarse. When attached to 400mm scope (which is a lot for a guide scope) it provides 5.6 arcsec guiding accuracy. DSLR pixel size when shooting prime focus on 2000mm FL telescope is 0.66 arcsec. So you get an error of 8 pixels. This effectively reduces resolution of a high end DSLR to about 1MP.Do yourself a favor and get a computerized autoguider that can do sub-pixel tracking.