Komura 2x extender for M.

[bocaburger]

Advertisement (gone after registration)

12 hours ago, Sumie said:

Sorry in advance for potential necroposting.

I wonder if this extender works for wider lens, say, 50mm primes or wide-angle primes? I see a 40 and 50 master mark on the viewfinder gadget.

Not expecting image qualities, if focusing is possible within EVF and no black corner appears it should be fine for me.

This seems to be one of the few 3rd party extenders(teleconverters?) available for mirrorless systems.

I have one of these Komuras...actually it's the second one, the first I paid about CA$350 for it (going back about 20 years was a ton of money) including the finder and case.  As someone else mentioned, the rangefinder coupling was poorly on mine.  And the finder was hazy.  So I sold it.  Years later I found just the TC for around CA$100, the RF coupling was also a joke, so I removed it (bc it rattled annoyingly) and used it only with a 135TE set at infinity.  Then when I got an M240 I dug the TC back out and have used it with the EVF on numerous occasions.  It will work with any M lens provided the lens' rear element doesn't protrude enough to inhibit mounting it to the TC.  The limiting factor I found is the TC is only critically sharp when utilising the centre of its optics.  So whatever lens used I find it best to keep it stopped down to at least f/4.  Which of course results in an effective aperture of f/8. 

[roydonian]

On 4/18/2025 at 5:49 AM, Sumie said:

I wonder if this extender works for wider lens, say, 50mm primes or wide-angle primes?

Extenders are intended for use with lenses of long focal length. At least one of the Japanese 'big-name' companies has arranged that its extender can only be physically mated with suitable lenses.