[lavascript]

A recent Marketplace listing prompted me go go find my Minolta MD glass. I didn't realize there was an adapter available. But there is, and it's got an element that will allow for infinity focus. It's only $29, but should I even bother?

I have a 28/2.8, a 50/1.7, and a 70-210/4.5-5.6.

I don't know anything about MD glass. Are these decent lenses? (I'm assuming that the zoom is mediocre at best.) Would they be worth the $29? I have the FA50, so I don't need a fast fifty, but I am in the market for a 28... hoping to pick up the Sigma 28/1.8 soon. Manual lenses really aren't suited to my style of shooting, but if these are really nice, I'd find time for them.

Thanks.

[boriscleto]

Look through this thread.

https://www.pentaxforums.com/forums/pentax-camera-field-accessories/96884-ada...addiction.html

Results will be similar to the Canon and Nikon adapters.

[Lowell Goudge]

I have the canon FD and nikon AI adaptors

They are like cheap teleconverters with low magnification the nikon one is 1.25 x and the canon one is 1.45x

I suspect the minolta one has a similar magnification to the canon one because the registry distance is similar and therefore the correction would be similar

Optically the converters have a little color bleed at wide open apertures but improve stopped down

I concluded that the best use is for normal to long lenses due to magnification

[lavascript]

Sounds like more of a "because I can" curiosity type of thing then, amirite?

Dunno if that's worth $30. Might be one day.

[sewebster]

Interesting, I have a couple MD lenses in the closet. The best is the MD rokkor-x 50 f/1.4 but I don't know if it's worth getting the adapter for that as I already have an FA50.

[RioRico]

I have some superb M/MC (older than MD) glass that I can't use and they aren't yet worth selling. I won't get an MD-PK optical converter because that will remove whatever is special about those lenses. I have the following options:

1) Butcher the lenses to fit them to Pentax -- for many, that's not feasible.
2) Get a Canon or m4/3 or NEX body upon which to mount those lenses.
3) Sell them to someone with an EOS or m4/3 or NEX or NX body.
4) Hang onto them until I get a better idea. Nope, I need money.

I am leaning towards option #3. It's just a matter of when.

[ve2vfd]

Guys, do like me! Get an X700 and use your MD/MC lenses for B/W work

Pat

[sewebster]

Yeah, I have an x700 too, so I figure I'll just keep the stuff around in case I decide to do film again. Can we not also convert the mount to K (with machining, infinity adjust etc.) as can be done for Canon, or is the register change the wrong way or something?

[clockwork247]

I have some superb M/MC (older than MD) glass that I can't use and they aren't yet worth selling. I won't get an MD-PK optical converter because that will remove whatever is special about those lenses. I have the following options:

1) Butcher the lenses to fit them to Pentax -- for many, that's not feasible.
2) Get a Canon or m4/3 or NEX body upon which to mount those lenses.
3) Sell them to someone with an EOS or m4/3 or NEX or NX body.
4) Hang onto them until I get a better idea. Nope, I need money.

I am leaning towards option #3. It's just a matter of when.

a 50mm f/1.4 still fetch a good 50 on ebay... 1/2 the price of a pentax M 1.4. I got a few MD/MC rockkor too, but i use them for reverse macro (actually i have 3 X 28mm lol) but other wise they rarely get use.

[sewebster]

Hmm, that's a cool idea to use the 50 for, reverse macro work, can leave it set up and not have to screw on a pentax lens... not that it takes so much effort

[clockwork247]

Yeah, I have an x700 too, so I figure I'll just keep the stuff around in case I decide to do film again. Can we not also convert the mount to K (with machining, infinity adjust etc.) as can be done for Canon, or is the register change the wrong way or something?

for the most part, lens from different brand can't be use on other brands... the only exception to this is the M42, which doesn't have a whole lot of "space eater" on the mount, if you look at all the bayonet mount (MD/K/FD ect...) they all have protruding aperture lever, makes it harder to get an adaptor to compensate for the space.

For example, the flange distance of pentax K mount is longer than canon/MD mount, but there's no chance to adapt them because of the way it's design...

nikon lens can't be use by any other mount, so is pentax, minolta, canon ect... the only working one is the M42, the rest of them need some sort of glass in the adaptor to get infinity focus.

[RioRico]

Hmm, that's a cool idea to use the 50 for, reverse macro work, can leave it set up and not have to screw on a pentax lens... not that it takes so much effort

That can seem attractive at first. The cons: When I got more than a few non-Pentaxable lenses, I had to ask myself, Just how many macro lenses do I need? Somehow I just didn't feel like comparing my bunch of Minolta, Konika, Canon, LTM, Petri, Fujica-X, and Miranda glass to see which reverses the best. And they all have such small working distances, reversed. And enlarger lenses are cheaper and easier to use. So I don't keep the luzers for extreme closeups.

for the most part, lens from different brand can't be use on other brands...

And that is so. Unadapted, most can only be used for closeups, if at all. Other than M39 and M42, the lenses I've adapted to PK mount are:

* Nikon non-AF: Dremel-away the "nub-and-arc" islands on the aperture ring.
* OM and C/Y: Use a Dremel to taper the bayonet flags to fit under the PK lugs.
* Exakta: Glue M39-M42 ring onto bayonet. Grind <1mm from M42-PK adapter flange.
* Petri: Remove the lens base. Glue on a M42-PK adapter.
* Argus C3: Drill hole in PK body cap. Glue lens into place.
* Some enlarger-projector-folder lenses: Same as Argus C3.

Some have reported conversion success with removing the base from Nikon, Olympus, Minolta, and other lenses, are replacing them with a flanged M42-PK adapter, or with the PK mount scavenged from a junked lens. That is too much surgery for my limited skills. There is also the Leitax project, for converting Leica R and other lenses. That's too much money for my budget.

So, without a machine shop and/or money, only a very few non-Pentax mounts can be adapted to PK. And that's partly why I like bellows, tubes, and enlarger lenses.

[Lowell Goudge]

there are a few points to be considered here with this adaptor, and also with modifying lenses.

I have both the nikon and canon adaptors which provide infinity focus, as stated earlier, these are optically corrected to account for the space required to allow for the mechanical interface, and increase in distance from the focal plane for each lens brand. The result is that these devices perfrom as low magnification teleconverters.

This means that (depending on adaptor mount and the actual magnification of the adaptor) your 50mmF1.4 will become something between 62mmF1.7 and 75mmF2

The values stated here are for the nikon and canon adaptors, as I noted in my first post, I expect the minolta adaptor to be closer to the canon in terms of magnification, but hopefully someone will have one and advise the actual magnification.

Due to the magnification, using the adaptor gives you different lenses, with different focal lengths.

When testing these, both with simple shots and for portraits, (I have access only to FD50F1.8 and AI50F1.8 lenses at present) they have a little Blooming or bleading of colors wide open, but are quite sharp when stopped down for normal shooting. Note also that kit lenses for film nikon and canon cameras were not as good as the comparable pentax lenses, so some of this performance is definitely the lens itself, however, my conclusion in the first post stands. These are really only useful for normal to tele lenses where the increase in focal length may have some use, and the adaptor is easier than modifying mounts.

I have modified mounts also, specifically for Vivitar and Kiron wide angles, from nikon AI and Minolta MD to Pentax K mount. The modification in these cases was done by removing the old lens mount, some grinding or filing of the aperture ring (to remove overhangs or interfering protrusions) and by careful control of the spacing for retention of infinity focus. I also found that infinity focus on these lenses (kiron wide angles specifically) is adjustable,

For the mount I used flanged M42 adaptors because they are cheap ($5.00 each) but they are also thin at 0.8mm which can cause an issue with countersinking screws. I find that after mounting the adaptor, some filing of the screw heads is required to ensure they are flush to the adaptor and do not scratch the camera's lens mount.

This approach is much better for wide angles, because you want them wide, you already give up field of view with the cropped sensor, and to give up an additional 25-50% in FOV due to magnification of the adaptor is not what you want.

I have not tried the adaptor on a quality telephoto yet. I have seen several Series 1 70-210F3.5 Version 1 lenses in canon or nikon mount, for $30 but have not yet picked one up to compare with my PK version of the lens.

Others have done this with some high quality lenses and gotten good results. These are posted in the thread on camera adaptors

Therefore, you will need to decide, but unless you find a really good lens in the mount you bought the adaptor for, it is probably not a way forward to aquire budget lenses.

I picked them up because from time to time, I come across cheap canikon lenses.

[sewebster]

In case anyone is curious, here is a video tutorial from some dude adapting MD to Canon:

motleypixel.com: Photography Forums and Lens Reviews

I have that same lens. Obviously this is involving machining etc. Does anyone know if there is any reason this sort of thing couldn't be done for K mount as well? I have the experience and equipment, but I don't think I'll be doing this because it isn't worth it. I'm just curious.

I might get the adapter though, as a 75mm f/2 lens sounds not so bad. Or remove the element and have a nice MF 50 for indoors (non-infinity).

[Lowell Goudge]

In case anyone is curious, here is a video tutorial from some dude adapting MD to Canon:

motleypixel.com: Photography Forums and Lens Reviews

I have that same lens. Obviously this is involving machining etc. Does anyone know if there is any reason this sort of thing couldn't be done for K mount as well? I have the experience and equipment, but I don't think I'll be doing this because it isn't worth it. I'm just curious.

I might get the adapter though, as a 75mm f/2 lens sounds not so bad. Or remove the element and have a nice MF 50 for indoors (non-infinity).

read my last post and that of riorico closelyt

we both have modified lenses from other mounts to K mount. It can be done, the "maching" is not that difficult, and does not require precision.

YOu have 2 options, either find a donor lens or use flanged M42 - K mount adaptors.

the conversions I did were for kiron 24mmF2 and 28mmF2 lenses (one nikon one MD) to pentax.

I opted to go simple and not couple the aperture, making them work like M42 lenses (just easier to mount)

the lenses I converted I got for free due to a problem with Kiron lenses and oil on the aperture blades.