I recently bought a non-APO 2X Extender (suitable for R series bodies) via eBay. Can this extender be used with APO lenses? Is there a marked quality difference between using the APO extender vs the non-APO extender? If so, is the difference more pronouced when paired with APO lenses or less? I have heard that using the extender halves the resolution (yikes!) while others have said the factor is not quite 1/2.

This question was asked in the LUG some time ago but I can't seem to find the answer in the archives. Thanks.

-- David (yeo_d@hotmail.com), September 04, 2001

Answers

The figures I've always seen are a nominal degradation of about 10% for a 1.4x and 20% for a 2x. Leica's converters should better those figures if anyone's can. I have the 2xR and 2xAPO. The 2xR was basically designed as a universal teleconverter for all f/2 and slower lenses from 50mm on up. Some compromises have to be expected. The non-APO 2x performs less well with longer lenses (over 250mm). With the shorter lenses (50-180, excepting the zooms and 100 APO Macro)the original 2x is a very decent performer and a lot more economical than the APO!

-- Jay (infinitydt@aol.com), September 04, 2001.

I had the regular Leica R 2X and wasn't too happy with the results with it--nothing too special about it in my opinion. Wide open edge performance is poor, and contrast is down. Even stopped down a stop, images lacked the snap I was used to from my Leica primes alone, and I did not keep the converter very long.

-- Andrew Schank (aschank@flash.net), September 04, 2001.

Hi Jay, thanks for the response. Are you saying that the non-APO 2X will not work with the 100mm APO? I have that lens and also the APO 180 f2.8 which is what I want to use the 2X R with.

Andrew, I have read a mix bunch of feedbacks about the quality of the non-APO 2X extenders - which is causing me concern since I have yet to receive my lens. One other LUGGER in the archives said that it's not great whereas 2 have said you cannot tell photos taken with the extenders from those with prime lenses. Whose view is closer to the "truth"? Your experience seems to contradict Jay's experience with his non-APO 2X extender. Could this simply be a matter of different expectations (don't mean to imply at all that Jay's standard is lower!)? Thanks for sharing your experience - much appreciated.

-- David (yeo_d@hotmail.com), September 04, 2001.

David, the images I shot with my 90mm + the 2X lacked the contrast and wide open performance I was used to in my Leica M and R lenses. You'll have to check yours out for yourself when it comes-no sense listening to me or anyone else or worrying about it until you do. Funny enough, I found a Kiron converter I use with my Nikon stuff that I am happy with that cost $50 on ebay-very little image loss and it doesn't knock the contrast down like most converters I've tried. Turns my 300mm F4.0 ED lens into a surprisingly good 600mm for the few times a year I "need" one.

-- Andrew Schank (aschank@flash.net), September 04, 2001.

David

I am sure it is all a matter of expectations. If you are the sort of person, who "always want the shot" then the 2X will be useful as you will get it, at albeit poorer quality than your other Leica shots. Others would rather let the shot go if the resulting quality is less than they are used to. The APO convertor has superior correction so will maintain APO correction on APO lenses, but I think you will not find that the correction of, say, even the 100mm Apo + 2X Apo at full aperture f5.6 will equal the 180 Apo at f5.6.

-- Robin Smith (smith_robin@hotmail.com), September 04, 2001.

If you have the 100APO and 180APO and want a 2x to use with those lenses I definitely recommend the 2xAPO. It is true what others have said, that even the best 2x will lower the contrast vs the prime lens itself. The contrast and resolution at full aperture of lenses like the 100/2.8APO, 180/2.8APO, 280/4APO, and 280/2.8APO are such that whatever contrast loss you get with the 2xAPO, IMO you'll still be left with images of outstanding quality. Many professional bird photographers stack 1.4x and 2x converters on 300/2.8 lenses with publishable results, and I have done this with both Nikon and Leica and I agree--but it's still not comparable to a top-notch prime lens all by itself. However, start with a 90/2 Summicron which already has a low-contrast rendering wide open, then add the non-APO 2x to it and you might very well be disappointed as someone already pointed out. I feel that the non-APO 2x is as good a non-APO 2x as you'll find, and after having used both for some time, I don't feel that the 2xAPO has much to offer the 50-90 lenses. But with the lenses you have, it will visibly outperform the non-APO 2x.

-- Jay (infinitydt@aol.com), September 04, 2001.

I have used 2X tele extenders from Leica, Nikon, Hasselblad and Mamiya645 for professional works, and always feel satisfied with the results. I use extenders because 1.I don,t like to carry bulky super telephoto lenses, 2. I like the 2X power with same close focussing distance which is ideal for my need to shoot macro telephoto pictures. Quality wise, I think most of us won,t even notice the difference. In my work - travel, landscape, nature close-up, etc., the 2XAPO is simply excellent, especially paired with 180/2.8APO

-- Deniek G. Sukarya (sipro@cbn.net.id), September 11, 2001.