Mamiya RZ 140mm LA Macro - Worth Getting?

[marcmarc]

Hi Everyone,
A local store has a used RZ 140mm LA Macro lens in decent looking shape. The asking price is about what I'm seeing them online for. I've always been intrigued with this lens. I don't really do macro work (at least not the kind where I would have to get the extension tubes) but I just want to hear from others who use this lens how they like it. It's difficult for me to convince myself on this lens because at f4.5 it's excruciatingly slow and I already own the fantastic 110mm which the 140 is awfully close to in focal length as well as a 180mm lens I bought for portraits which I rarely use. So it's a bit of an awkward fit in what I already have, yet I seem to recall reading it was a favorite among some people using the RZ system. Is there anything really stand out about this lens that I may not be aware of (like will it scrub my bathroom once a week ;-)

 

[polyglot]

The 110 is noticeably softer at high magnifications than near infinity, whereas the 140 is sharp to the corners at any extension if you set the floating element correctly. I've seen high-res scans from one and it's probably the only remaining lens for the RZ that I intend to actually buy (I have the 37, 65 M-LA, 110 and 250APO). It ought to be great for tight headshots, etc, but if you only shoot sweeping vistas then don't bother.

It's also about halved in price ($400 to $200) over the last 5 years. Not sure why that is; RZ gear is generally cheaper but most lenses haven't fallen that far and some are appreciating.

 

[marcmarc]

Thanks Polyglot. I too have noticed the pricing phenomena you mention. I have the 50mm ULD with the floating element which I got for a song some years back; it seems to have held its price fairly steady. Maybe there are just a lot more 140's out there which may bring down the prices.

After posting this thread I did a bit more more searching online and one user mentioned that this lens has a very narrow DOF and that he sometimes had missed accurate focus. This may have been due to not setting the floating element correctly I suppose...

 

[polyglot]

Narrow DOF is kind of unavoidable at high magnifications, it's not a function of the lens' design until you get very close to the subject and Pupil Ratio starts to matter (and I have no idea if the pupil ratio differs between the 110 and 140; neither should be telephoto or retrofocus which are the usual causes of non-unity ratios). If you shoot at 1:2 or 1:1 you're going to get razor-thin DOF no matter what the lens is, so nailing focus basically requires a tripod and macro rail.

If you're shooting intermediate magnifications like portraits, is f/4.5 really going to be an issue?

The instructions say you can set the floating element AFTER focusing, so I expect any focus shift to be imperceptible. If it's set wrong though, you will get increased aberrations... in the worst case it will be as bad as a lens with no floating element. There will be coma, softness, etc, even in the plane of focus; it will be worst in the corners.

The big question though: does it solve a specific problem for you? Are your 110mm closeups insufficiently sharp? If not, I wouldn't bother because it doesn't bring anything to the table other than better sharpness at high magnification.

 

[marcmarc]

Good points Polyglot. I am very happy with the 110 lens; it's fast and light so I use it a lot hand held. I often leave the floating element ring alone when using the 50 lens and have not noticed any difference to those time I do set it. I'm a horrible judge of distance anyway.

 

[MattKing]

The floating element will have the greatest effect on corner resolution and contrast.

I use the RB version of the 140mm macro. Most often I'm using it at small apertures rather than larger ones, so its relatively slow speed only really affects viewing and focusing, and even then it is rarely a problem.