One day recently I came across a Tamron 2x teleconverter in a cheap bag of kit. So, basically free. After trying it and researching it, I realized it was just an awful chinese TC that had no redeeming qualities. K-R mount too, but the pin is rounded so it doesn't seat into the screw drive fortunately. It does have A contacts and an aperture lever. Hmmmmmm. After much whacking with a screwdriver and hammer, the glass elements shattered one by one. I blew out all the glass dust and voila! instant 25mm extension tube. I find it works best with lenses that have good close focusing ability. The 16-45 superb in its rendering in macro with a tube, but the working distance is extremely short and is unusable below probably 30mm or so. The 70-200 I have does decently and has nice OOF rendering, but just doesn't get nearly as close. It gets better magnification at 70mm. The 35-105 I just acquired does pretty well and can certainly reach 1:1 when you combine with its built in macro mode, though it doesn't give that much more magnification with a tube.
I don't see the point personally in having AF. Your DOF is so paper thin even at f11-f16 that its much easier and convenient to just move back and forth. Catch in focus works well here when you want to just grab something in the center. I find it best to just take multiple shots, adjusting focus sightly back and forth. I find the 28-50ish range seems to work best at getting towards 1:1, but you are pretty much focusing a few inches away from your subject like this. I would imagine a 100mm macro would give better OOF rendering and would also give you better slightly better working distance, but even at 100mm, 1:1 requires you to get pretty close. I haven't tried any primes. I like zooms because you can use the zoom to quickly adjust focus and working distance by zooming in and out. I have also tried close up lenses that were good, but I didn't like how they OOF areas as much as there was a pretty decent drop in IQ towards the edge of the frame. They also weren't getting me close enough. The 25mm tube is pretty good for large magnification. Now I just need to get a ring flash.....just what I need...more things to lust after... ;) I'll post some pics with the tube a little later on here. It has served me well, though I do get hotspots sometimes. I don't know if the tube is reflecting (its all black inside) or if the rear elements of my problematic lenses aren't coated. It does it with the 35-105, which is likely coated on the rear element, so I'm thinking it might actually be the tube that could use better paint inside. On Wed, Jul 10, 2013 at 3:50 PM, Bruce Walker <[email protected]> wrote: > That's very cool, Darren. I've often thought I'd love to try macro > with my 50-135. I figured that the SDM pass-through was not terribly > useful as manual focus would most likely be required, but for $100 > I'll keep an eye out for one of these things. > > > On Wed, Jul 10, 2013 at 2:16 PM, Darren Addy <[email protected]> wrote: >> Tripped across a piece of equipment that I was not aware of this >> morning and (just in case others didn't know about it either) thought >> I would pass it along. >> >> It is a AF extension tube that works even with SDM lenses. It is >> called the Kenko Uniplus Tube 25 and it was once made for Pentax, now >> extremely hard to find. As good fortune would have it, I no more than >> learned about it and looked and there was one listed on ePray (from >> Japan) that had only 9 views when I snatched it up (Buy It Now). >> >> I'm passing this info along because it can turn your DA* 50-135mm or >> even your DA 40 XS into a superb macro lens. If you don't believe me >> check out this French Pentaxian's work. If you only have time to look >> at ONE, check this out: >> http://www.flickr.com/photos/15251430@N03/9168541564/ >> >> Here all ALL of his images tagged with Uniplus: >> http://www.flickr.com/photos/fs999/tags/uniplus/ >> >> The macro shots taken with the DA 40 XS can be seen here: >> http://www.flickr.com/photos/fs999/tags/pentaxda40mmf28xs/ >> >> Macros taken with the combo of the Uniplus Tube and the DA* 50-135mm are >> here: >> http://www.flickr.com/photos/fs999/tags/pentaxda50135mmf28sdm/ >> >> I don't own either of those two lenses. He tells me that the Uniplus >> Tube works with anything over 20mm (with a 20mm the subject is just 1 >> cm from the front of the lens). >> >> I'm curious to see how it works with reducing the minimum focusing >> distance when used with the Bigma (and how much of the infinity end >> you lose). >> >> If you really want to blow some time, FS999 has a lot of very engaging >> sets on Flickr. >> http://www.flickr.com/photos/fs999/sets/ >> >> -- >> "Photography is a Bastard left by Science on the Doorstep of Art" - >> Peter Galassi >> >> -- >> PDML Pentax-Discuss Mail List >> [email protected] >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. > > > > -- > -bmw > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
