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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

New but probably wrong insight about lowlight (1 Viewer)

Relative brightness is arrived at by EP squared. Therefore an 8x32, a 6x24 and a 10x40 all have the same relative brightness since all have an EP of 4 mm. However, the 10x will give you more resolution than the 8x and the 6x. (Btw there is an interesting paper on the human eye and resolution by Mssrs Donnelly and Roorda)
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„I don't understand from where you get the idea that higher magnification concentrates the incoming light more.“

Hi, you said it yourself, just with other words:

„The objective gathers the light and the gathered light is proportional to the area of the objective.“

So the light gathered is the same for 8x42 and 10x42.

„For example: whether you observe the moon at night with a 7x50 or 50x50 the total light from the moon reaching your eye is the same.“

So that very small pupil of 1mm for your theoretical 50x50 has the „light more concentrated“.
My words were just different as yours:
I came to +25% via this:

5.25mm/4.2mm i come to a factor of 1.25, which means +25%

Correct me if I am wrong, maybe I just misunderstood something.

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With a 50x50 the moon covers 25 degrees but has low surface brightness.

With a 7x50 the moon covers 3.5 degrees with high surface brightness.

But I suppose the total moon light is the same.


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