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Harmsway! · 04-11-10, 07:32 PM

Be careful what you do with these figures. Transmission is only about the efficiency of light making its way through the glass. It is not the end all in brightness. I have spent lots of hours looking through scopes and I can tell you the higher the magnification the dimmer the image.

The brightness intensity seen at the eyepiece is inversely proportional to the square of the magnification.

When you double the magnification, you get one quarter the brightness. ie, 1/2 squared.

I find the scope images above at 30 and 21% are not at all representative. It is not as simple as photo-shopping the brightness numbers into an image. The truth is our minds eye plays a major roll in the apparent brightness. Those of you who have taken photographs with a fast lens know that film or CCD will capture light different then the natural eye sees.

04-11-10, 07:32 PM	#15
Harmsway! XO Join Date: Jul 2002 Location: Florida Posts: 400 Downloads: 126 Uploads: 0	Be careful what you do with these figures. Transmission is only about the efficiency of light making its way through the glass. It is not the end all in brightness. I have spent lots of hours looking through scopes and I can tell you the higher the magnification the dimmer the image. The brightness intensity seen at the eyepiece is inversely proportional to the square of the magnification. When you double the magnification, you get one quarter the brightness. ie, 1/2 squared. I find the scope images above at 30 and 21% are not at all representative. It is not as simple as photo-shopping the brightness numbers into an image. The truth is our minds eye plays a major roll in the apparent brightness. Those of you who have taken photographs with a fast lens know that film or CCD will capture light different then the natural eye sees. Last edited by Harmsway!; 04-11-10 at 08:35 PM.