Sunday, February 01, 2009

Goto and Tracking performance of my LXD55

LXD55 on a Gitzo G106

Review of my LXD55

Believe it or not, I never tried out the GOTO performance of my LXD55 despite that it had been with me for more than two years (or even longer). I used it primarily inside my home and since the window is too small, GOTO is never useful for you only have a couple of very obvious targets to shoot. I didn't own a car and taking out a mount like this is not easy at all, so the LXD55 only used for tracking the planets, the moon and the sun.

My friends suggested a camping trip and one of my friends can drive me there virtually and so I took my LXD55 out. There was a 15 minutes short walk in the countryside but it's still manageable despite I would say it's close to my personal limit with all the camping stuff, photography stuff as well as telescopes, batteries, counter weight.

With careful polar alignment using the built-in polar scope, GOTO is surprisingly accurate! With my C5 and a 20mm eyepiece, that means over 60x, all my selected targets were in the field immediately after the beep! That polar scope was only roughly aligned when I first purchased this mount, so it shouldn't be in good alignment supposingly. But I was proved wrong later.

After visual observations of all the available targets (with a C5 and light polluted sky - pinky orange!!!), I mounted my Canon 200mm f2.8L with my Canon 450D there to start photography.

No guiding was used, the counter weight is moved to the top of the shaft to make it less imbalanced. Guess what, all the stars remained pinpoint except the first exposure. I did exposure up to 2 minutes only since my friends were feeling cold, but 2 minutes unguided for this low cost mount is enough for me! The first exposure is not very excellent because the backlash of the gears I believe, since when you first GOTO a target, the gears might not be fully engaged. So, if you can wait for say 10-20 seconds (at most), you will have perfect tracking after that.

GOTO between different targets are nice indeed. For example, before my first exposure, I GOTO to Sirius to let the lens do the autofocus itself, and then I slew to my target, turn on live view and then fine tune the focus, it's just so easy!

In conclusion, this aging refurbished LXD55, self-hypertuned with lithium grease indeed worked exceeding my expectations! The accuracy for tracking and GOTO are both fantastic for visual purpose, as well as for short exposure deep sky imaging. If you are not really determined to get world class shots, this mount is more than you will need.

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