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that you may not need to guide the exposure at all. For f/6.3 imagining the optional f/6.3
Reducer/Corrector is needed. (see Optional Accessory section at the end of this manual).
Imaging at f/10 (Lunar or small planetary nebulae)
f/10 imaging is more challenging for long exposure, deep sky imaging. Guiding needs to be very accurate
and the exposure times need to be much longer, about 25 times longer than f/1.95. There are only a select
few objects that work well at f/10. The moon images fine because it is so bright, but planets are still a bit
small and should be shot at f/20. The Ring nebula is a good candidate because it is small and bright. The
Ring Nebula (M57) can be imaged in about 30-50 seconds at f/10. The longer the exposure the better.
Imaging at f/20 (Planetary or lunar)
f/20 is a great way to image the planets and features on the moon. With the PixCel CCD camera and
optional Color Filter Wheel, it is easy to take tri-color images of planets also. When imaging the planets,
very short exposures are needed. Many cameras have trouble taking images under .1 seconds. The PixCel
camera can image at .01 seconds exposures due to the design of the CCD array. The exposure lengths range
from .03 to .1 seconds on planetary images. Focus is critical as is good atmospheric conditions. Generally
you will take one image after another until one looks good (see AutoGrab feature in the PixCel Operating
Manual). This is do to the atmospheric "seeing" conditions. For every 10 exposures you might save 1. To
image at f/20 you need to purchase a 2x Barlow and a T-adapter or Radial Guider.
