Curve_in Loc: Virginia

I currently have a Nikon AF-S NIKKOR 55-300mm f/4.5-5.6G ED VR that I use with my D7000. I'd like to get a sharper shot of the moon, so I was thinking of getting a 500mm lens. I can get a Nikon 500mm F8 Reflex-Mirror in a package deal. Would that one work better than just cropping the image from the lens I have?

Nikonian72 Loc: Chico CA

I own and use a Nikkor 500-mm f/8 mirror-reflex lens, purchased new in the early 1970s. I have used it to photograph the moon, but it is not as sharp as a 500-mm all-glass lens, and the moon image is still quite small on the sensor. Using a 1.4x or 2x convertor will NOT work to satisfaction. This is why serious astro-photographers use dedicated astronomy telescopes for moon and celestial photography.

Several manufacturers make/sell 500-mm reflex photography lenses. Nikkor has the best IQ of the lot. For the right price, it can be a good buy.

Dngallagher Loc: Wilmington De.

The mirror lens will be a longer reach, but it may not be the best for sharpness, especially of the moon. The 300 mm lens you have gives you a 450mm field of view on a DX camera anyway. You might do better with a Sigma 150-500 telephoto or a Tamron 150-600, or even a 1.4 extender.

The 1.4 extender with your 300 mm lens would equal using a 420 mm lens, add in the crop factor of 1.5 and you get a field of view of a 630 mm lens.

dlmorris Loc: Loma Linda, Ca

Inch for inch, (diameter) or maybe mm for mm, (focal length) you will never get as sharp an image with a mirror lens as with a conventional lens or a quality refractor. The reason is simply that the secondary lens degrades the image greatly. Why do we keep our camera lenses so clean, and worry so much if there is even a tiny scratch on it, then go out and buy a lens with a big mirror right in the middle, degrading the image and diffracting the incoming light. Some have gotten good images with them, and they are cheap enough to play with, but if you really want detail, stick with lenses.

dlmorris Loc: Loma Linda, Ca

It would be an interesting comparison between a 300mm conventional lens and a 500 mm mirror lens, both images cropped to the same size. Maybe I'll try it sometime, as I have both...