Just got a Pentax ME Super in eBay and two lenses from a friend of mine.

One of the two is a 200mm Shacht prime.

I have also won on eBay, 10 minutes ago, a x3 teleconverter and I was thinking if I add a second TC how good would the results be.

I know that everything will become darker, but it's also true that a full moon is super bright.... And if it's too dark I can also go with higher ASA film.

I considered also that a mirror lens of such focal length would be at least f/8, but would be really difficult to justify to the wife. (aaah!)

I was thinking at another x3, having a 1800mm lens to shoot at the moon should be quite a blast...

I know it may well be a simplistic view, but I wouldn't mind trying... Is it really worth it or am I planning in actual fact to throw in the bin £6?


2 Answers 2


I think you are mostly likely wasting £6. A teleconverter is going to cause some image degradation, and stacking two of them more so. Even with a top notch lens and teleconverters. With inexpensive TC's off eBay I think the likelihood of the images being usable is slim. The corners will most likely be very soft, and as you are increasing magnification, the moon is going to be extending into those corners at 1800mm.

It is possible that if you stack TC's you may not be able to focus to infinity. Which would be inconvient given how far away the moon is ;)

500-600mm will get yo great moon images. You will probably get better quality cropping these than you will get from a 2nd teleconverter.

  • \$\begingroup\$ Thanks MikeW! for the super quick reply, and for the advice, obviously. I know that the corners lose sharpness, but I was referring to this gif I found on the NASA website regarding different focal lengths and moon photographing (actually solar eclipse, but the black round thing is definitely the moon). Actually at 2000mm it should still be smaller than the frame. company7.com/graphics/film1.gif Anyway, I checked some moon pictures in google and actually the quality of multi TC systems is quite bad, in the meaning that those pictures look like taken from a 20 years old newspaper! \$\endgroup\$
    – user8871
    Mar 7, 2012 at 19:50
  • \$\begingroup\$ You need a 4700mm lens before the moon covers all four corners of a 35mm frame. 1800mm will get you a nicely framed image. \$\endgroup\$
    – Matt Grum
    Apr 16, 2012 at 12:52
  • \$\begingroup\$ It would end up being much cheaper to buy a good telescope and a T adapter. \$\endgroup\$
    – nwcs
    Apr 16, 2012 at 13:12

If you've got the equipment already (or can borrow some), it's worth trying. I wouldn't buy another Teleconverter with the expectation of getting something good, though.

Long ago I stacked a Kenko 1.4x and a 2x on a Nikon telephoto to try to get shots of the moon, just as you want to do. The results were better than I expected. I think the results were about the same as my previous attempts with one teleconverter and having a cropped print made from the negative, but that was long ago and I don't have the photos anymore and I may be misremembering. But as yet another thing to try, it was a fun exercise.


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