Imaging Techniques
Webcam imaging with Philips ToUcam 740 Pro
Chapter 5 - Premises for high resolution imaging
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Chapter
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Chapter
4 
To be able to obtain high resolution images two main factors have to cooperate:
1. Condition of equipment
Collimation
Proper scope collimation is a must! Imaging without the best collimation
possible is simply a waste of opportunities and will result in a loss
of possible detail resolution. Collimation should be checked before any
imaging session and readjusted if necessary, ideally after the scope reached
total thermal equilibrium. Instructions on collimating different types
of scopes are available by various sources. If the scope hasn't been tossed
around a lot after it's last collimation, a check or small corrections
performed on a high magnified airy disk pattern of a focussed star should
be sufficient. The better the seeing, the better the precision of the
collimation will be.
In addition to the scope collimation all parts inside the optical path
during imaging such as diagonal mirrors etc. should be checked for correct
adjustment.
The potential of many high quality scopes is wasted by improper collimation.
Scopes are designed to be collimated, don't hesitate to do so!
Thermal equilibrium
A scope works best when thermal equilibrium with it's surrounding is reached. Depending on scope type and size and temperature difference between the scope's storage location and observing/imaging place the cooldown can take upto several hours. Cooling fans speed up the cooling process and help a scope to follow changing temperatures.If a scope hasn't reached thermal equilibrium tube currents will occur and blur and distort the image.
2. Atmospheric conditions
Seeing
Example of mars in heavy seeing conditions - click image
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Chapter 6 |