6x telescope or 4x telescope - Printable Version

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6x telescope or 4x telescope - Don Schaeffer - Jun 18, 2008

This may be the ultimate stupid question, but i want to get beyond guesses.
My 55-200 mm Nikkor lens works like an 82-300 mm (in 35 mm terms) becauise of the 1.5 sensor correction. In 35 mm terms (where 50 mm is normal), it should look like 6x telescope through the viewfinder. Now when I look through the vuiewfinder of my SLR am I seeing a 6x telescope (30 mm) through the lens or a 4x telescope (200 mm). Do they used masks on the viewfinder or what?

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6x telescope or 4x telescope - NT73 - Jun 18, 2008

It depends on the telescope's starting and finishing magnification.
In terms of magnification they will be the same (4 x approx)
Nikkor (55-200) or 82.5 - 300 is still only 3.6363636 times magnification, Because you multiply both ends by 1.5.

(If your telescope has 4 times magnification, and the large end was 100mm, the small end would be 25mm)


The viewfinder is just a glorified square, set to give you the view that the sensor gets from the lens.
If you have an full size sensor camera, then the viewfinder would be set to give you the view that that sensor gets.

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6x telescope or 4x telescope - Don Schaeffer - Jun 19, 2008

Gotcha. That's what I thought.

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6x telescope or 4x telescope - NT73 - Jun 20, 2008

Well it is not quite accurate but will suffice I think.
A telescope (the big ones anyway) have separate eyepieces that alter the effective magnification or something like that.

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6x telescope or 4x telescope - Don Schaeffer - Jun 21, 2008

Yes they are just magnifying glasses to magnify the image.

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