APM 107/700 APO has replaced WO ZS105ED as my primary imaging instrument. The objective diameter is 107mm and focal length 700mm giving an F6.5 system. For imaging I usually use it with Astro-Tech 2" field flattener, which works very well with this telescope and my cameras. This flattener corrects the telescope field curvature, which might be a problem when imaging with cameras with larger chips. When I want wider field (or lower F ratio), I use it with TS 2" 0.79 reducer/corrector instead, which gives F5.135 focal ratio and reduces focal length of the telescope to 553mm. Although much more elaborate (and expensive) reducers/correctors exist for this scope this one gives decent image quality also.

The telescope is very well built, suitable for both imaging and visual use. It is a high quality instrument for a reasonable price. I like its "classic" looks very much. The telescope is delivered with a hard case, tube rings and Vixen style dovetail bar (good thing that I equipped my GM-8 with head that accepts both Vixen and Losmandy dovetails). OTA is well baffled with knife-edge baffles and flat black paint, for high contrast and no reflections.

This is the objective of APM 107/700 APO. This telescope is an apochromatic refractor, meaning that the chromatic aberration (CA) of its objective is well corrected. This objective is an air spaced triplet. One of the three lenses in the objective is made of exotic FPL-53 glass with special dispersion (ED) properties, which is a key factor in eliminating CA. The objective is fully multicoated for better light transmission.

The objective is protected with retractable dew and glare shield. The shield can be locked in place with two thumbscrews. The dew shield is sometimes not enough to prevent dew forming on the objective. That is why I have to use dew heater as well.



As a standard APM 107/700 is equipped with precise and sturdy 3 " APM rack-and-pinion focuser. The focuser is dual-speed with 1:10 microfocus knob. Focus lock and tension adjustment thumbscrews are also provided. The focuser tube is engraved with millimeter scale. The focuser is rotatable, which helps framing objects.

The focuser handles CCD camera like QSI503WSG without any effort. It is rated for loads up to 6kg. The focuser has adapters for several types of threads, as well as 1.25" and 2" clamps, for securing various imaging or observing equipment.

Here you can see my typical imaging setup with APM107/700 telescope and QSI583WSG camera on Losmandy GM-8 mount. Autoguiding is done via SBIG ST-i guiding camera. With tube weight of 5.7kg the telescope is a good match for imaging with my GM-8 mount .