Photoclubalpha

I have had two Minolta cameras, an SRT102 (ca. 1975) &, more recently, an A1. Both have been fine cameras, & I intend soon to get an Alpha 700.

When I acquired the SRT102, I purchased with it an MC Rokkor PG 50mm 1:4 lens, and then a 100mm 2.5 lens, both of which were very highly rated in tests at the time. I would dearly love to be able to use these lenses on my Alpha 700, if possible. I expect that I would have to use them manually, both focus & f-stop & shutter settings. However, I continued to follow Minolta when they shifted to Maxxum auto-focus lenses, & believe I remeber correctly that the new Maxxum cameras were back-compatible with the older Rokkor Minolta-mount lenses. Do I understand these things correctly, or is there a reason I cannot use these fine old lenses?

Dulaney

Dulaney_Ward wrote:... & believe I remeber correctly that the new Maxxum cameras were back-compatible with the older Rokkor Minolta-mount lenses. Do I understand these things correctly, or is there a reason I cannot use these fine old lenses?

Dulaney

Well I have some old MC mount Rokkors here from my Minolta SRT101s and also some later MD mount lenses all of which work with SRT101 and X700. However I have just, very gently, offered up an MC 58mm f1.4 to a Dynax7D and it will not fit because, as I suspected, the diaphragm coupling pin fouls structure inside the camera’s mount.

Have a look at my gallery picture for an idea of what you could use that old Rokkor for. You can mount it face to face with another long focus or macro lens to substantially increase magnification, lighting and depth of field then being limitations as to subject.

In my Alpha gallery see the less than perfect pic’ (I was trying out a three off-camera flash wireless set up using 2 x Minolta 5600HS(D)s and 1 x Metz MZ-54i, hassle getting them all to play ball, with the Metz not having such an intuitive interface but it is good once understood, meant I ran out of time to take a better shot and avoiding the blue cast on the top of the Minolta controller) of an Alpha 100 with a lens combination and Minolta Twin Flash 2400 and controller assembled.

There was no backwards compatibility, but Minolta themselves did once offer (briefly) a 1.2X manual converter which allowed this, and in the USA only, a very rare longer (I think 1.4 or 1.7X) teleconverter with an autofocus mechanism inside it which did the same. You can buy manual adaptors which retain focus confirmation and have the 1.2X factor quite easily, they range in price from $40 to $100 but they all seem pretty much the same. I have a Haoda Fu example here which gives tolerable results using MD lenses, you lose some sharpness and getting the focus right is difficult. Also, with the new A200-300-350 you can only use manual exposure.

David

Minolta once offered the 2× M/A Converter-S and 2× M/A Converter-L which basically were variants of the well-known tele converters MD 300-S and MD 300-L---same glass inside but without any aperture couplings and with A bayonet mounts at their rear ends. Both have focal-length factors of 2×; the 'S' versions being meant for lenses of 300 mm and shorter, the 'L' versions for 300 mm lenses and longer (lenses of exactly 300 mm may be used with either version).

Today, these converters show up on eBay occasionally and sell for EUR 50 - EUR 100, sometimes for even less when badly described and no-one realizes what the item actually is. The image quality is pretty good when used as intended, i. e. with lenses of 50 - 300 mm ('S') or 300 - 1,600 mm ('L'), respectively. The 'S' version will also work with wide-angle lenses but at slightly reduced image quality.

As far as I know, Minolta never offered tele converters for SR-mount lenses with focal-length factors other than 2×, neither regular ones nor those to fit A-mount cameras.

Sigma once offered a 1.6× tele converter for use with SR-mount lenses on A-mount cameras, with auto-diaphragm, meter coupling, and auto-focus! The quality is fairly good but it ONLY works with the 1st-generation AF cameras, i. e. Minolta 9000AF, 7000AF, and 5000AF.

The adaptors offered by Haoda Fu and by many others (Dörr, Beroflex, Hama, etc.) have no meter coupling, and their focal-length factor is close to 1.25×. The optical quality is rather poor with most lenses so it doesn't make much sense to use them for serious work. I knocked the glass out of mine---it's two elements, not one as commonly believed---and use it as an SR-to-A-mount adaptor for my SR-mount macro equiment on A-mount SLR and D-SLR cameras (extension length 9.5 mm).

-- Olaf

01af wrote:Minolta once offered the 2× M/A Converter-S and 2× M/A Converter-L which basically were variants of the well-known tele converters MD 300-S and MD 300-L---same glass inside but without any aperture couplings and with A bayonet mounts at their rear ends. Both have focal-length factors of 2×; the 'S' versions being meant for lenses of 300 mm and shorter, the 'L' versions for 300 mm lenses and longer (lenses of exactly 300 mm may be used with either version).

Today, these converters show up on eBay occasionally and sell for EUR 50 - EUR 100, sometimes for even less when badly described and no-one realizes what the item actually is. The image quality is pretty good when used as intended, i. e. with lenses of 50 - 300 mm ('S') or 300 - 1,600 mm ('L'), respectively. The 'S' version will also work with wide-angle lenses but at slightly reduced image quality.

Having had an old Minolta XG2 SLR in a previous wet film photographic life, I have some ancient completely manual MC fixed focus lenses. I hoped one of those old 2X M/A-S teleconverters would convert them without losing too much image quality. In particular I hoped that my old 200mm HMC Hoya f3.5 at a 2X 400mm would give me a useful extra boost past the end of my SAL 18-250mm on my Sony A350. Here's its first trial in practice



Here's the Flickr URL which gives you the option of viewing the full size image (which I reduced to 67% from the original 14MP because the detail resolution wasn't up to the full 14MP). On a very dim misty day manual focus was very hard to judge, so I wound it out to the infinity stop, used f8, and hoped for the best. Seems to have worked well enough. I was pleased to discover that the A350 in manual mode allowed me to use camera metering of manual exposure. Shame it refuses to do manual focus confirmation, which technically should be possible and would be very useful.

http://www.flickr.com/photos/chris_malcolm/2924542778/

Here for comparison is the SAL 18-250mm on 250mm. The vignetting is due to using a long lens hood to keep rain (slight drizzle) off the lens.



http://www.flickr.com/photos/chris_malcolm/2924541814/

It's easily seen that the 2X converted 200mm is sharper than the SAL 18-250mm at its rather soft 250mm extreme reach, even in these rather poor conditions. I have some other fixed focus lenses to try out, plus repeating this in sunny conditions if global warming hasn't entirely banished the winter sun for ever here.

Not too shabby Chris!