Telescope Reviews: Takahashi Mounts

I wouldn’t think the lack of PEC is such a big deal if you’re guiding – especially if you’re not shooting at really long focal lengths. Also, as was mentioned, the EM-200 is comparable to the Mach1GTO and the EM-400 is best compared to the AP-900.

I own an EM-200 and have had it for several years. I bought it because the AP Mach1GTO wasn’t available at that time and I fell in love with the polar alignment scope. Some of the other posters started to hint about the other features, beyond PEC, that you might find important to your decision. The lack of a goto handbox has been mentioned, although you say that you’ll be doing imaging so you’ll have a computer and there’s also the option of using a PDA if you want. There are some other Tak/Temma personality quirks that you should know about as they may matter, or not.

My EM-200 Temma II does not have the greatest goto. It’s accuracy is directly related to the quality of your polar alignment, but I frequently have to hop-scotch across the sky to get to a target. For example, if the telescope is pointed to the north east and I decide to image a target in the southwest then I’ll goto a star about a quarter of the way, center the star on the CCD, do a “synchronize” and then go on to another star part of the way to the target. If I hopscotch then Temma will always land the target in the center of the CCD chip. If I try to go straight there, especially with a meridian flip, the Temma will almost always miss the target. I know other people do this trick with other mounts, but the Temma seems to need more help than most mounts. In the course of an evening, it isn’t a big deal because it only adds a couple of minutes to my work flow, but if you have your heart set on automating your imaging work, it may be important. Some of this may be related to the lower resolution encoders, some may be related to the simplicity of the sky model that the Temma uses. I’m sure that a lot of the issue relates to my failure to always take my time in aligning. After all, even with a great alignment scope, if I’m sloppy, the results will be sloppy. Regardless of the reason though – it may be a factor for you too.

Unless you use the ASCOM drivers, the Temma has no ability to park itself or other little niceties. I have used the ASCOM driver with mixed results. It’s a quality piece of software and usually works well, in some cases though, I may get the initialization wrong and the driver will slew the mount in an unexpected manner – like into itself. Many others have GREAT results with the ASCOM driver so I’ll chalk that up to my error. However, it’s the reality for me and it may be for you too. I use “The Sky” and the native driver built into The Sky.

If you plug the autoguider into your camera (or at least, a camera like mine – an ST-2000XM) and the camera is switched off then the Temma will start wandering off of target. If you leave the “speed switch” on the hand controller on the “high” setting then the mount will try to calibrate and autoguide at high speed rather than slow speed. None of these quirks are deal breakers, but every once in a while if I’m not careful, I’ll forget and they will bite me. Lastly – an obvious point – the polar alignment scope kicks butt, but if you are in a location where you can’t see polaris then you’re back to drift aligning. The AP mounts have software to help you get around this issue.

I’d say in summary that the EM-200 works really well and it has very high quality mechanics. From a software angle, it isn’t bad so much as it is more primitive than other manufacture’s systems. The upside of the simplicity is that, well, it's simple. Once you do a polar alignment, you just pick any single star that you like, align it and synchronize the Temma system. FAST!

These are just my experiences, more talented or more careful users may have different results. I do love my EM-200 though and its quirks have in no way made me want to trade it in for a different mount.

-Ken