Moon Photography: Focal Length Comparison



When it comes to imaging the moon—size matters. Puny lenses may not cut it. Focal length greatly influences how much the Moon will fill the camera’s sensor.

All images taken with a Canon Rebel XSi and the following lenses / telescopes:


  • Canon EF 18-55 Zoom Lens

  • Canon EF 50mm Macro Lens

  • Canon EF 100mm Macro Lens

  • Opteka 500mm Mirror / Lens

  • Orion 279mm Astrograph

  • Orion 800mm Observer Refractor

  • Orion 1300mm Maksutov


The Canon Rebel XSi has a 1.6x crop factor, which means the focal lengths need to be multiplied by 1.6.


100 * 1.6 = 160mm

500 * 1.6 = 800mm


** These images are not an accurate reflection of what they would look like taken with a full frame DSLR. **

None of the photographs are cropped.

Many people glorify a highly magnified image of the moon, but you rarely see an image, which portrays the larger picture. Don’t know what the hell I’m talking about? Hold on.

Moon — 50mm

Look closely—the moon is in theresomewhere.

Did you find it?

This particular perspective is close enough to see fuzzy lunar detail and far enough to see the void of space. A lonesome world drowning in a sea of nothing—that’s something every world has in common. If you were standing on the lunar surface, and gazed upon Earth, the same darkness would be there, engulfing your home.

Moon — 18mm

Where did the moon go? Oh! There it is. Do you see it? Yeahthat’s the moon. A whole moon shrunken, and practically void of visual characteristics—it’s difficult to believe that’s a world—which harbors monolithic scars. Photograph taken with a 18-55 kit lens (18mm).

The moon may have a separate history, but it has a history. Sure, sure, this gray world may not be hospitable, lacks an ocean, doesn’t have an atmosphere, I get it. But does that really make the moon any different from Earth? Every world is lost within the grandeur of the void.

Tycho CraterMono-1
Tycho Crater (1300mm / 2x Barlow)

Where was I…

Right! Lunar focal length comparisons. Please don’t judge me because of my temporary distraction. I put together a panorama image, consisting of nine separate photographs. Feel free to click on the image and take a closer look:

The panorama image looks like crap because I had to shrink it. Sorry.

If you were wondering how large the moon looks taken with a 279mm, and couldn’t sleep at nightwellthank me later. Go get some sleep. As you can see: 279mm is a little on the puny side. I’m not casting judgments, but if you’re looking to fill your camera’s sensor, I suggest increasing the focal length.

If you’re using a crop sensor, a 1300 focal length telescope enlarges the moon quite a bit. Short tube refractors are simply too stunted. I also used an 800mm refractor, not quite a short tube, but it was still pretty weak, especially compared to a 102mm Maksutov.

So there you have it! Feel free to use the lunar panorama image as a general reference. Save the photograph to your computer, come back often and study it—do as you wish. I’ll add to the image once I acquire more lenses / telescopes.


Published by FlyTrapMan

I have no idea what I'm doing.

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