Don Glenn

Lives in United States United States
Joined on Feb 23, 2003


Total: 3, showing: 1 – 3
On article Sony reveals AA-filter-less Cyber-shot DSC-RX1R (66 comments in total)
In reply to:

Create Dont Imitate: The era of the AA filter will go down as a black mark in photography.

Putting a filter over the sensor with the intent of "smudging" the image... has to be one of the worst ideas in the history of photography.

I think you need an AA filter, but maybe in reality the lenses blur the image enough that the AA filter isn't as needed? The AA filter "removed" the high frequency data so the sensor wouldn't sample it as lower frequency data. But if there isn't any high frequency data, you wouldn't need it.

Link | Posted on Jun 28, 2013 at 18:21 UTC
On article Canon launches EOS 60Da DSLR for astrophotography (224 comments in total)
In reply to:

K_Photo_Teach: Pentax could compete with this if they did a special astrophotography DSLR because of the GPS adjusting the sensor using the sensor stabilizer to prevent start trailing.

Would LOVE for other manufacturers to bring out similiar tech

I like how you are thinking, but you need an accurate digital compass and of course tilt data in 3d. Got me thinking about other options, it is a fun subject, but i think it would end up being too expensive to build for the number that would sell.

Maybe firmware that assumes a stable tripod, it takes a few pictures over 2-3 minutes, calculates the star movement, then correct based on that data. That could be done. But the camera would have to remain stationary, and the focal length would have to be fixed.

Link | Posted on Apr 3, 2012 at 14:51 UTC

My concern is quality. The MAK telescope design is great and I would use that as a lens without any concern. But...

There is a design shortcut that the cheap mirror lenses like to use that kills sharpness. The design should be corrector-concave mirror-convex mirror, and possible flattening lens/group. The cheap design is corrector-concave mirror-lens-flat mirror-lens-possible flattening lens/group. I have a cheap lens and I disassembled it to see what was wrong with it (bought it used, so I didn't care much).

The lens-flat mirror causes a reflection that kills the sharpness. The lens never seemed to be in focus.

If I knew the design was correct, I would buy one. Currently I look for suspicious element-group counts.

Link | Posted on Feb 3, 2012 at 20:40 UTC as 24th comment | 4 replies
Total: 3, showing: 1 – 3