Minolta MD Lenses modified on A900?

[aformaphoto]

I have seen on the web an old MC Rokkor 58mm f1,2 modified in the lens mount and used on A900.

What do you think, David, about this?

Is there some convenience to modify old lenses and to use them on the A900?
What could be problems, IQ and use issues?

Would be nice to use some trusty zoom I loved so much in the field, like the MD Zoom 35-70mm f/3,5 and MD Zoom 70-210mm f/4 (manual version of beercan with very very useful Depth of Field scale on the barrel)!

Modifying deeply the lenses in the mount, their use on the field will be very slow due to the lack of exposure and diaphragm automatism and there is the risk that their performances could be not so satisfactory on the A900 too.

Is better to abandon the intention, maybe, and to sell everything?

I have a set of some beautiful prime lenses for my Minolta XM too and I stopped to use them from a couple of years:
MD 17mm f/4;
MD Rokkor 24mm f/2,8;
MD Rokkor 35mm f/2,8;
MC Macro Rokkor 50mm f/3,5;
MD Rokkor 100mm f/2,5.

Regards

[alphaomega]

Interesting question posed by aformaphoto. I went from MD to digital through R1 to now A700/350. I still have all my MD lenses including the 50 mm F3.5 macro and Sigma 70-210 F2.8 APO. I would love to use particularly the macro and have looked at some of the MD/MA converters available on ebay, but not made a move yet as not sure how they would function. I would welcome clarification from "someone in the know" on how to use MD lenses on Sony DSLRs.

[Javelin]

I have the Minolta 2x MD/AF converter. it works well with my Minolta MD lenses but not so well with my 75-200 F2.8 sigma which was a fantastic lens on my X700. I will try an adaptor thaty doesn't have the magnification on it but I haven't had the chance to pick one up yet,

[paul_32]

I tried an MD 250mm mirror last week, but as long as no manual, the a900 reports "no lens mounted". At least aperture priority would have been nice.

[David Kilpatrick]

I have one of Haoda Fu's overpriced 1.2X converters. It does little good to the lenses I have tried (50mm f1.7, 200mm f4.5, MD 28mm f2. and really, the end result was not worth using.

I think the proper conversion done on the 58mm f1.2 MC Rokkor is worthwhile, and maybe the 50mm f1.4 as well - there's one on eBay right now. If anyone converted an MC 100mm f2 it might be good. And, of course, there were some interesting mirror lenses 800mm and 1600mm, but finding one to convert might be hard.

The 250mm f5.6 mirror lens was always bad for vignetting on full frame and might make a neat lens on APS-C with a direct (no optical converter) modification.

David

[alphaomega]

Thanks for your comments David. Just what I thought when I saw these converters on ebay and that is why I did not purchase one. I was wondering if one of the MD/MA converters without glass would make my MD 50 mm F3.5 makro lens usable on my A700 & 350 although it would not focus on infinity. It might be worth trying.

[sparaxis]

As much as we may curse Minolta for obsoleting our MC/MD lenses back in 1985, there really is no good way to use them digitally.

(Unless you want to use a 4/3 Olympus that is - Shock! Horror!)

It pains me too, as I have 17 MC/MD lenses covering 17mm to 300mm.

I bought one of the Generic 1.2x converters from B&H some months before the 7D was released. After playing around for awhile I came to the conclusion that it was not worth it. Manual focussing on a modern AF screen is difficult at best, and coupled with the noticeable loss of contrast becomes almost impossible. This is coupled with a significant loss of quality and ghosting and hot-spots. The end result cannot compete with a cheap AF zoom. If you are using one of the latest bodies you are forced to use manual exposure as well. (Sony needs to fix that - Otherwise how do you use something like a lensbaby)

I also found a genuine AF-MD 2x converter on Ebay. Quality is much better but the 3x effective crop factor is not. It has it's uses if you can find one though. I have a Vivitar 135/2.3 series 1 that actually works very well. My Kiron 24/2.0 turns into a wonderful 50/4.0 softfocus lens!

An adapter without glass is definitely usable for macro work. I have a classic Vivitar series 1 90mm macro. It works fine. A 50mm would be more restrictive with respect to maximum focussing distance.

The Olympus option is interesting. Cameraquest sells an adapter that allows MC and MD lenses to be mounted (with some limitations) on Olympus 4/3 bodies. The Rokkor files has a very good write up. (http://www.rokkorfiles.com/olympus.htm" onclick="window.open(this.href);return false;).

Getting an old 58mm 1.2 converted is possible, but even now these are still hard to find and quite expensive when you can find them. Then you have to deal with manual focus. Although f1.4 lenses from the 1970's could be quite good, most of the f1.2s were actually quite poor. My inclination would be to keep my eyes open for a first generation AF 85/1.4 instead.

Great Bokeh, low contrast, gentle soft edges. On an APS-C camera, a great "portrait lens", on an Alpha900, probably a great disappointment perhaps.

Alan

[alphaomega]

Thank you sparaxis for your comprehensive reply. I conclude that really the only option for me is to purchase the non glass converter MD to AF and use it with my 50 mm Macro lens.

[InTheSky]

The Old Minolta Mount and the last AF Minolta/Sony mount use the same exact 4 screw mount. If the Auto-focus is not important for you, almost every MD lens is quickly convertible to a AF mount lens if you have back metal mount left from a broken Auto-focus lens.

For some Old Minolta, like the F1.2, you will need a back lens mount from a 70-210mm F/4.0 or greater, because the back optical glass is too big to fit smaller diameter lens.

I have converted a 58mm 1.2 rokkor two weeks ago and this was done by using a M42 confirm focus adapter.



All Old Md lens only need to make the aperture spring to get inactive. By doing that, the aperture is all the time at is bigger setting (following the back lens control aperture). This means that you don't have to create an build a special mechanism to make the aperture control working.

Here is my 58mm F/1.2 modified and picture taken on with the A900. http://www.pbase.com/nadeauf/58mm_f12_on_a900 My copy of 58mm F/1.2 is not very good, because the coating on the back lens is a little bit damage, bringing me some bad reflection in to high light contrast.

I should received soon a 135mm F/2.8 rokkor, and i'm thinking of buying an old 300mm F/4.5 to see how it works on the A900.

Regards,

Frank

[Dr. Harout]

Frank, thank you very much for your input. It means a lot for much of us.
Thanks a lot mon ami.

[Cogito]

There's an explanation here on how to modify the MC/MD mount to AF.
I still use a converter and all of my MC/MD lenses on my 7D - so I doubt it's any different on an A900.
This with the 50mm MD f3.5 macro

And this with the 500mm MD f8 cat - well I had a BIT of difficulty hand-holding it .....

[aformaphoto]

PRAISE to Frank and Pete,
for their fundamental and illuminating contribution to the debate.

I have found on the web someone converted the MD Zoom 35-70 f3,5 to Canon Eos lens mount too, because he thought that the lens was of excellent quality and it was particularly worthwhile.

I was thinking about selling my Minolta manual focus lenses. But on Ebay Minolta manual focus lenses bidding prices are now very low.

Being loyal Minolta users, we should make an attempt at some conversion, before to deliver to the history (or to the trash) some fine optical instrument, built to last and not to be involved in consumerism.

Regards

[InTheSky]

i think no Minolta's lenses have the right to go in trash . Or even some old lens too. We have to think that in the future, they should be able to make better sensor that will reduce the effect of CAs and other element that was not so high in film. Meaning that some lens today are not as good as they should be, because of the sensor limitation for angle of light and reflection.

I pretty sure that some old gear will become very good for newer generation of Digital sensor.

Regards,

Frank

[sury]

I have used MD/MA adapter (bought on Ebay for US$15.00) on my A100 quite effectively for the last one year. It is possible my photos are
pedastrian but I am a rank amateur who enjoys photography and experimenting. So far I have done reasonably well with the following adapters
for MA mount.
T2 -> MA mount. Used with a old Bausch&Lomb 800mm mirror lens
T1/T2 -> MA Nikura 500mm mirror lens
M42 -> MA adapter (US$10) on Hanimex 135/2.8, Pentax 300/f4, Pentax 55mm/1.8, Vivitar extension tubes (US$10)
MD -> MA mount on about half a dozen MD mount lenses including Vivitar Ser 1 90mm/2.8 (my favorite), Tokina 70-210/f2.8 and others.

Here is an example of Hanimex 135/2.8 with Vivitar extension tubes using M42 to MA (no focus confirm feature), manual mode, hand held
shot on A100.

http://farm4.static.flickr.com/3192/291 ... 3e39_b.jpg

I am now learning how to use the same on my newly acquired A900 (2 days old). I finding that A900 overexposes images when the indicator is at 0 and
"underexposing" seems to help. To me, half the fun is in learning these things.

Are any of those 15 blade M42 lenses worth the money? Typically they sell around US$80-$100.

with best regards,
Sury