Tamron 500mm Mirror Lens

[wil_ussery]

<p>Is there an adapter that will allow me to place a Pentax K mount, Tamron 500mm lens on a Mamiya 545 Pro TL body?</p>

[dhbebb]

<p>Almost certainly there will be nothing ready-made due to lack of demand. Companies such as SK Grimes in the States and SRS Microsystems in UK could make you an adapter, but the register (distance from film to lens mount) of the Mamiya will certainly be greater than that of the Pentax, which means you will not get infinity focus.</p>

[rodeo_joe1]

<p>No. The lens register (flange to focal plane distance) is shorter than what will allow infinity focus on a Mamiya 645. Added to which the lens image circle may well not cover the 645 format.<br>

Even adapters to go the other way round - M645 lens to Pentax K 35mm body - aren't that common and are quite expensive.</p>

<p>I'm really not sure why you'd want to do this anyway. The whole point of such a long lens is surely to get a high magnification. Putting the lens on an MF body would only give you the same image size and magnification, but on a bigger bit of film.</p>

[dan_fromm2]

<p>RJ, I agree with you that the OP can't use his mirror lens on his 645.</p>

<p>I don't agree with you about "the same image size and magnification." This because I moved up from 35 mm to 2x3 to solve a flower photography problem. With 35 mm, when I shot a bloom at high enough magnification to get good detail I had to give up its setting. When I shot to include the setting I lost good detail in the main subject. With 2x3 I could get reasonable to good detail in the main subject and its setting too.</p>

<p>As for focal length, well, with a longer lens I didn't have to be as close to get the magnification I wanted.</p>

[ondebanks]

<p>Mamiya themselves made a 500mm f8 mirror lens for their 645 SLRs, so there is no need to seek an adaptation of something made for a smaller format and which won't reach infinity focus. In addition, the Mamiya lens, introduced in the 1980s, has reportedly distinctly better optics than the norm for this design. You can find them for around €/$400 these days. </p>

[rodeo_joe1]

<p>Dan, the same lens will give the same magnification for a given subject distance regardless of what size camera you fit it to. You could stick that Tamron 500mm lens on a 5” x 4” camera (and a lot easier than on an M645), but it would still only give you the same magnification and image size as on a 35mm camera. And the small amount of film area used would still limit the amount of detail that could be seen.</p>

<p>What you’re talking about is using a completely different lens on a completely different format camera and shooting from a different subject distance, and that’s obviously not the same thing at all.</p>

[scott_murphy5]

<p>I doubt there is but it is a moot point because the exit image size for the 35mm lens would almost certainly not fill a 6x4.5 format so you would get some vignetting</p>

[harveysteeves]

Actually, here is where I kind of disagree with the rest. It might just work. I have placed a 35mm mount mirror lens on the

front of a mf body and got infinity focus. It was a Vivitar branded one and a t-mount. Since this lens was very light, I

always figured if I cut a hole in a body cap, and mounted this on the lens, it might be usuable. The Tamron might be a

little more difficult. I should look, I have a couple.

[rodeo_joe1]

<p>Harvey, unless the lens also fully covers the MF format with acceptable definition across the frame, the point still stands that it won't give any greater magnification than if it was on a 35mm body. Might as well use it on the camera it was designed for and save the hassle, since the MF advantage of a greater film area would be lost.</p>