Comparison of Orion 120 ST with Orion 80 ED refractor
Comparison of ISO setting vs exposure time with a Canon Digital Rebel
Results of the modification of the Canon Digital Rebel
Shooting H-Alpha with the modified Canon Digital Rebel
Sirius MV1 filter - eliminates blue halos around bright stars
Broadband filters - lessens the effects of light pollution
- California Nebula - Lumicon Deepsky filter comparison
Comparison of Orion 120 ST with Orion 80 ED refractor
The Orion 80 ED refractor has been receiving excellent reviews since its release. It is designed to compete with apochromatic refractors costing 3 to 4 times as much. I recently purchased one and thought it would be interesting to show some comparison shots between this scope and my Orion 120ST achromatic refractor. I've taken some nice shots through the 120ST refractor and I thought it performed quite well. I was very surprised by the comparison!
These daylight shots demonstrate that the 80 ED not only has almost no chromatic aberration, but it also easily out resolves the larger scope. I attribute this in part to the slower focal ratio of the 80 ED.
For the comparison, both scopes were mounted side by side on a Losmandy G11 mount and the exposures were taken less than 30 seconds apart. A Nikon 990 camera was coupled to a 17mm Plossl eyepiece for these images. Each set of images was taken several times. The fine detail comparisons suprised me the most. The increase in resolution and detail in the 80 ED images is real and is not due to poor focus on the 120ST or other anomoly.
No processing other than resizing/cropping was done on any image.
- Trailer tire with chrome highlight
- Trailer hitch
- Pine tree comparison of fine detail
- Horse hair comparison of fine detail
Here are a some images of the Moon comparing the two scopes. For these shots, both scopes were mounted side by side on a Losmandy G11 mount and the exposures were taken within 5 minutes of each other. A Nikon 990 camera was coupled to a 40mm Plossl and 10mm Radian eyepiece for these images. Each set of images was taken several times. The results of these shots echo the daylight images above.
- Wide shot with 40mm eyepiece (reduced to fit screen)
- Closer shot with 10mm eyepiece (reduced to fit screen)
- Full resolution with 10mm eyepiece (cropped portion of the above image with no resizing)
NOTE: See the moon shot above under the Sirius MV-1 filter section for a comparison of the 120ST with and without this filter.
Comparison of ISO setting vs exposure time with a Canon Digital Rebel
Is it better to use a shorter exposure with a higher ISO setting or a longer exposure with a lower ISO setting?
Find out here.
Results of the modification of the Canon Digital Rebel
Hutech replaced the factory IR filter with one that allows more of the red spectrum to pass to the sensor.
See the results here.
Shooting H-Alpha with the modified Canon Digital Rebel
Can the modied Canon Digital Rebel hold its own against hypered Tech Pan when shooting through a Hydrogen Alpha filter?
See the results here.
