supplied by Jiøí Drbohlav
Comparison star sizes in the centre and on the edge of the field:
Comparison star images using and without using of the photocorrector:
Another photos:
diameter 135 mm
speed 1:4,2
focus 550 mm
tube diameter 160 mm
tube length 510 mm
The camera is fixed with bayonet to the photocorrector.
It is possible to turn the camera to the desired position.
Pictures of the globular cluster M13 in Hercules. On the first picture the cluster is in the centre of the field; the star image size is 3x3 pixels.
On the second picture the cluster is in the edge of the field; star images have a comparable size to the previous picture. Both of the pictures have 30 seconds exposure in order to minimize errors (seeing, driver).
M13 in the edge of the field. The first picture is made with the photocorrector; the second without them. The coma-deformation of the star images is distinctly visible.
with the corrector
without the corrector
All the photos are made by the camera Canon EOS 300D. The camera was set to the sensitivity of 800 ISO. The photos are not corrected.
   
Double cluster X+h Per
preview - click to get the whole pictureCluster NGC 6940
preview - click to get the whole picture