rdeloe
Well-known member
In January of this year I started a thread about the Fuji GSW cameras because I was interested in harvesting a 65mm lens from one. Over the course of the thread, with help and advice from wonderful forum members, I realized that a better choice was the Mamiya N 65mm f/4 L, one of the lenses for the Mamiya 7 system. I bought one, and mentioned that I'd provide a bit more feedback.
In a nutshell, I really like this lens. I was looking for a lens I could use on digital view cameras with my Fuji GFX 50R as the 'back'. My minimum expectations were that it would be excellent at f/8 across the frame; allow me to focus my F-Universalis by rail; and movements would be unrestricted. The last point is a concern with Mamiya 7 lenses because some have a lot of lens sticking out behind the mount. I also hoped it would be easy to re-mount. Note that to use one of these like I planned, you have to be willing to ruin it for Mamiya 7 cameras by removing all the bits and pieces that are extraneous or prevent its intended use, including removing the shutter blades.
The lens not only met my requirements, but also it opened up some photographic doors that have been closed for a long time because I've been shooting exclusively with my digital view cameras. I had to build a mount board for my F-Universalis, and discovered that the Mamiya 7 mount, when simplified, goes onto a simplified Mamiya 645 camera-side mount. I built a mount board for my F-Universalis, and on a whim build an adapter to use hacked Mamiya 7 lenses directly on my GFX 50R. Along the way, I've re-discovered the simple pleasure of walking around with a camera and one lens.
A truly pleasant surprise was discovering that this lens is really good at f/4. The MTF charts told me it wouldn't be a good choice for photographing brick walls. I expected the edges and corners to be weak at f/4 if I focused on the centre of a flat subject, and they are. But the central part of that brick wall would be nearly as sharp as the lens gets. And if you focus at the very edge of the image, the subject at that position will be sharp too.
I find the out of focus areas parts of scenes photographed wide open to be very pleasing, both in front and behind of the plane of focus, and the transition from in-focus to out-of-focus is smooth. It's been many years since I shot a lens wide open, but I'm doing that a lot with this one. I'm not a fan of "bokeh balls" and sun stars, but I was curious to see how the lens does with those. If you like that kind of thing, it seems fine to my eye.
At the other end of the aperture range, I am pleasantly surprised by how good f/16 is. Of course it's not the position of maximum sharpness thanks to diffraction. However, I'm finding that f/16 is an absolutely usable aperture on my GFX 50R. A little bit of extra texture in Lightroom brings back some of the detail lost to diffraction. Interestingly, I find that f/16 is more usable on the Mamiya N 65mm f/4 L than it is on a GF 45-85mm f/4 that I used to own (when used at 65mm). I don't have the GF lens anymore, so I'm not going to stand too firmly on this claim -- but when I compared two images of the same subject (albeit different times), I saw more blurring in the GF lens. It might simply be that one or the other isn't accurately f/16. Nonetheless, I use f/16 all the time so I'm glad it's very usable.
I'm still trying to decide where the "sweet spot" is in terms of overall sharpness across the frame. I think it's f/8. At f/5.6, peak sharpness is reached, but the edges and corners can still be a bit soft on a brick wall test. By f/8, sharpness in the centre is falling a bit behind f/5.6, but the whole 33mm x 44mm frame on a flat subject is ready to go. For most of my photography, f/8 and f/11 are going to be familiar apertures; at f/11 there's no softness at all in the edges and corners, but of course diffraction is a bit more obvious.
The lens has a few other optical strengths that are worth mentioning. I was delighted to discover that chromatic aberration is not a concern. At f/4 I can sometimes see a few pixel's worth of purple fringing in the places one would expect to see it, but it cleans up well in Lightroom, and is simply not present by f/8. I also really like the level of contrast (high without being painful), and the colours (very pleasing and natural to my eye). I have some lenses that need a lot of work in Lightroom to get colours right, but this one is easy.
Of course I bought this lens for use on a technical camera, so it needed to be perform well during tilts and shifts. Happily, tilt and swing happen very close to the rear nodal point, so there's very little recomposition needed. I have several lenses that do need a lot of recomposition, so that's not a deal breaker -- but it's nice that this one doesn't. The circle of good definition is large -- 89mm per Mamiya's specs. That translates to around 20mm of shift on GFX. I would take a bit more, and the lens can do it, but with this lens I'm getting mechanical vignetting from the top edge of the sensor cavity at 20mm, so a bigger image circle wouldn't be useful anyway. Note that this is not the fault of the lens. Those of you using medium format backs with 0mm flange distance don't have to worry about this, but my sensor is deep in the body, so the "cavity" in which it lives blocks the light on strong shifts.
Image quality at large shifts and f/11 (the aperture I'd be using if I shifted 20mm) seems very good so far. I've mostly been shooting with my simple adapter so I'm reserving a confident judgement on shift performance for the future. At this time I can say that light falloff is moderately strong (not surprising given the published Mamiya data), but thankfully there's no lens cast. Were I making flat stitched panos with large shifts, I'd probably use an LCC frame to sort out the light falloff.
All in all, this is a wonderful lens. In addition to its optical strengths, it's a delight mechanically (small, compact, not too heavy, aperture ring up front where I like it, and buttery smooth focus).
In a nutshell, I really like this lens. I was looking for a lens I could use on digital view cameras with my Fuji GFX 50R as the 'back'. My minimum expectations were that it would be excellent at f/8 across the frame; allow me to focus my F-Universalis by rail; and movements would be unrestricted. The last point is a concern with Mamiya 7 lenses because some have a lot of lens sticking out behind the mount. I also hoped it would be easy to re-mount. Note that to use one of these like I planned, you have to be willing to ruin it for Mamiya 7 cameras by removing all the bits and pieces that are extraneous or prevent its intended use, including removing the shutter blades.
The lens not only met my requirements, but also it opened up some photographic doors that have been closed for a long time because I've been shooting exclusively with my digital view cameras. I had to build a mount board for my F-Universalis, and discovered that the Mamiya 7 mount, when simplified, goes onto a simplified Mamiya 645 camera-side mount. I built a mount board for my F-Universalis, and on a whim build an adapter to use hacked Mamiya 7 lenses directly on my GFX 50R. Along the way, I've re-discovered the simple pleasure of walking around with a camera and one lens.
Garbasaurus: a sculpture by Greg Elliott installed along the Speed River in Guelph, ON. The sculpture is made with junk pulled out of the river during a cleanup in 1999. Mamiya N 65mm f/4 L at f/4.
A truly pleasant surprise was discovering that this lens is really good at f/4. The MTF charts told me it wouldn't be a good choice for photographing brick walls. I expected the edges and corners to be weak at f/4 if I focused on the centre of a flat subject, and they are. But the central part of that brick wall would be nearly as sharp as the lens gets. And if you focus at the very edge of the image, the subject at that position will be sharp too.
I find the out of focus areas parts of scenes photographed wide open to be very pleasing, both in front and behind of the plane of focus, and the transition from in-focus to out-of-focus is smooth. It's been many years since I shot a lens wide open, but I'm doing that a lot with this one. I'm not a fan of "bokeh balls" and sun stars, but I was curious to see how the lens does with those. If you like that kind of thing, it seems fine to my eye.
Bokeh balls all over the place at f/4.
At the other end of the aperture range, I am pleasantly surprised by how good f/16 is. Of course it's not the position of maximum sharpness thanks to diffraction. However, I'm finding that f/16 is an absolutely usable aperture on my GFX 50R. A little bit of extra texture in Lightroom brings back some of the detail lost to diffraction. Interestingly, I find that f/16 is more usable on the Mamiya N 65mm f/4 L than it is on a GF 45-85mm f/4 that I used to own (when used at 65mm). I don't have the GF lens anymore, so I'm not going to stand too firmly on this claim -- but when I compared two images of the same subject (albeit different times), I saw more blurring in the GF lens. It might simply be that one or the other isn't accurately f/16. Nonetheless, I use f/16 all the time so I'm glad it's very usable.
Normally I'd rely on a bit of tilt and/or swing to help me get the plane of focus where I wanted it, but for this image I had to rely on f/16, and it didn't let me down.
I'm still trying to decide where the "sweet spot" is in terms of overall sharpness across the frame. I think it's f/8. At f/5.6, peak sharpness is reached, but the edges and corners can still be a bit soft on a brick wall test. By f/8, sharpness in the centre is falling a bit behind f/5.6, but the whole 33mm x 44mm frame on a flat subject is ready to go. For most of my photography, f/8 and f/11 are going to be familiar apertures; at f/11 there's no softness at all in the edges and corners, but of course diffraction is a bit more obvious.
One of the many small limestone churches in Guelph, ON. This is f/8.
The lens has a few other optical strengths that are worth mentioning. I was delighted to discover that chromatic aberration is not a concern. At f/4 I can sometimes see a few pixel's worth of purple fringing in the places one would expect to see it, but it cleans up well in Lightroom, and is simply not present by f/8. I also really like the level of contrast (high without being painful), and the colours (very pleasing and natural to my eye). I have some lenses that need a lot of work in Lightroom to get colours right, but this one is easy.
Of course I bought this lens for use on a technical camera, so it needed to be perform well during tilts and shifts. Happily, tilt and swing happen very close to the rear nodal point, so there's very little recomposition needed. I have several lenses that do need a lot of recomposition, so that's not a deal breaker -- but it's nice that this one doesn't. The circle of good definition is large -- 89mm per Mamiya's specs. That translates to around 20mm of shift on GFX. I would take a bit more, and the lens can do it, but with this lens I'm getting mechanical vignetting from the top edge of the sensor cavity at 20mm, so a bigger image circle wouldn't be useful anyway. Note that this is not the fault of the lens. Those of you using medium format backs with 0mm flange distance don't have to worry about this, but my sensor is deep in the body, so the "cavity" in which it lives blocks the light on strong shifts.
Image quality at large shifts and f/11 (the aperture I'd be using if I shifted 20mm) seems very good so far. I've mostly been shooting with my simple adapter so I'm reserving a confident judgement on shift performance for the future. At this time I can say that light falloff is moderately strong (not surprising given the published Mamiya data), but thankfully there's no lens cast. Were I making flat stitched panos with large shifts, I'd probably use an LCC frame to sort out the light falloff.
All in all, this is a wonderful lens. In addition to its optical strengths, it's a delight mechanically (small, compact, not too heavy, aperture ring up front where I like it, and buttery smooth focus).
Out on a sunny morning after freezing rain. Mamiya N 65mm f/4 L at f/5.6
