Mamiya 645 300mm f5.6 on Hasselblad X2D: ULD vs. Sekor C versions (and vs the Mamiya telezoom!)

The Mamiya 645 300mm f5.6 came in two versions. The newer ULD (left) and the older Sekor C (right). How will they compare when adapted to the 100 mpx Hasselblad X2D? Does ULD-glass really matter?

From time to time I need a lens longer than 150-200mm. The only “native” option available for the Hasselblad X2D is the adapted HC 300mm f4.5. Undoubtedly a stellar lens, but big and heavy (198mm and 2120g, plus the XH adapter!) and quite expensive (currently USD 5980). So, in line with what I previously have mused around, I have tested out third-party adapted lenses. I reviewed the Mamiya 645 Sekor C 300mm f5.6 a few weeks back. You may want to read that blog-post first for background. Although it proved to be an ok sharp lens, it didn’t blow me away. Actually, the Mamiya 645 105-210mm ULD zoom at 210mm and then cropped to a 300mm angle of view, was marginally better than the 300mm Sekor C! However, the version of the 300mm I tested was an older version (Sekor C) and I pretty soon found out that it was later made as an updated version with ULD glass. Ultra-low dispersion glass is supposed to reduce chromatic aberration and increase sharpness, and the ULD glass in the zoom blew me away. So, I purchased the ULD version of the 300mm too and decided to put it on a side-to-side comparison with the older Sekor C-verison. The question is: will I be more impressed by the 300mm ULD-version, and how will it compare to the older 300mm sekor C, the cropped image of the zoom at 210mm, and my current gold-standard in this focal length: the Hasselblad HC 150mm f3.2 with the Hasselblad H 1.7 TC?

The ULD version of this lens can easily be found in the second-hand market. It currently retails for around 100-300 USD on ebay. As usual, I found my sample on ebay from a well-reputed dealer in Japan and purchased it for USD 129 plus shipping. It arrived a few days ago in as-new condition without any signs of being used before. As usual, if you are in the marked for a used lens, I would advice you to browse around until you find a sample in mint condition without fungus, balsam separation, haze or scratches. And for this particular lens, be sure that the front of the lens reads “ULD-C”.

Size and build

As can be seen from the image above, the ULD-version has an almost identical exterior to the older sekor C-version. Only a few cosmetic details set them apart. The fonts on the barrel are slightly different, and the rubber on the focus-ring has a different pattern. Otherwise, they are identical in size and weight, so I suspect identical optical formula, except using different glass.

Build quality it top notch, in line with the other Mamiya 645 lenses I have worked with. Wonderful wide focus-ring with a long throw and exactly the right resistance. Aperture-ring with some resistance and nice clicks. The built-in hood works as intended. This lens also looks great in the X-series cameras.

For a medium format 300mm it is quite compact and lightweight. It is very similar in size and weight to the 105-210 mm f4.5 zoom, and handles pretty much like that one on the camera. That means well balanced, not too front-heavy, and the camera can be mounted on a tripod without additional support on the adapter or the lens. At least for shorter periods of time and in little to no wind.

The two 300mm versions (left and middle) and the 105-210 f4.5 ULD zoom (right).
Full frame equivalent focal lengthca 240 mm
Length (lens only)164 mm
Length (with adapter and caps)217 mm
Weight (lens only)710 g
Weight (with adapter and caps)916 g
Filter Ø58 mm
Close focus4 m
Build in hood?Yes
Adapter usedKipon Mamiya 645X1D

Test shot

I used my regular subject to test this lens. For why I chose this scene and how it was done, see details in one of my previous posts, e.g. the test of Nikon Series E 135mm f2.8. In short, I wanted to do a real-life test of this lens in a setting close to how I usually use my telephoto lenses.

Capturing details: Hasselblad X2D-100c, tripod (Gitzo systematic series 3 with geared head), 2 sec timer, iso 64, auto white balance, aperture priority, some depth to the scene, focus close to infinity, manual focus on the tower in 100% live view with fully open lens, f11 for exposure, e-shutter.

Raw-file imported to Lightroom where it has undergone initial sharpening (deconvolution, raw-sharpening): Amount 30, radius 0.5, details 100. No other adjustments for initial evaluation.

Distortion and vignetting

As you may appreciate from the unedited test-image above, there is no trace of vignette at f11. I found the same with the older 300mm Sekor C version, so no surprise there. This lens was of course designed with a large image circle (6×4.5) in mind, so this could be expected. Also, there is no distortion to speak of.


Sharpness and chromatic aberrations were evaluated on 300% enlargements in centre, left edge and extreme lower left corner, corresponding approximately to the red squares in the frame above. The crops are shown below. To the left in the crop you will see the unedited file (only deconvolution sharpening) from the 300mm ULD and on the right you will see the unedited file from the older 300mm Sekor C. Drag the slider to alternate between the two lenses.

300% view of image center. Left: Mamiya 300mm f5.6 ULD. Right: Mamiya 300mm f5.6 Sekor C. Unedited images (only raw-sharpening)
300% view of image edge. Left: Mamiya 300mm f5.6 ULD. Right: Mamiya 300mm f5.6 Sekor C. Unedited images (only raw-sharpening)
300% view of extreme lower left corner. Left: Mamiya 300mm f 5.6 ULD Right: Mamiya 300mm f5.6 Sekor C. Unedited images (only raw-sharpening)

The ULD version is significantly sharper in image center and on the edge of the frame. Sharpness somehow levels out towards the corner. If I was pushed, I would have to give the edge to the newer ULD-version also in the corner. Look at the tree-branches in the left hand side of this edge-crop. Overall, the ULD version is sharper than the older Sekor-C version, and actually very impressive.

Chromatic aberration

Color fringing. Left: 300mm ULD. Right: 300mm Sekor-C.

Ultra low dispersion glass is designed to reduce chromatic aberrations and thus e.g. color fringing. To my surprise, the ULD-version (left) display comparable amounts of fringing to the older Sekor C version without ULD-glass (right). Maybe a tad less. But quite a lot more than the ULD-zoom (not shown here) which was very impressive in this respect. However, as shown below, color fringing is easily removed with a tick of a box in lightroom.

Mamiya 645 300mm f5.6 ULD. Unedited image (left) vs. image with chromatic aberrations removed in lightroom (right).


As with the older Sekor-C version, I am very happy with the size, weight and handling of this lens. It fits the X2D body nicely and feels well balanced. Having a 300mm like this is very nice.

Optically, the newer ULD-version is quite a lot better than the older Sekor C. It is well above my demands for sharpness, also in the corners, and color-fringing is easily removed in Lightroom.

Two questions remain though: How does it compare to the very impressive Mamiya 105-210mm f4.5 ULD zoom, and is it better than the Hasselblad HC 150mm f3.2 with the 1.7X teleconverter? I have compared edge-crops of these below. The sample images from the Mamiya zoom and teleconverter adapted HC-lens are of course cropped to the same angle of view as the Mamiya 300mm f5.6 ULD.

Left: Mamiya 645 300mm f5.6 ULD Right: Mamiya 645 105-210 f4.5 ULD. Vews of image edge, corresponding to 300% on the 300mm. Raw-sharpening and removal of chromatic aberrations only.
Left: Mamiya 645 300mm f5.6 ULD. Right: Hasselblad HC 150mm f.3.2 with Hasselblad H 1.7x converter. Vews of image edge corresponding to 300% on the 300mm. Raw sharpening and removal of chromatic aberrations only.

To address the easiest part first: The Hasselblad 150mm with the 1.7x converter (255mm) extra cropped to the same angle of view, is no match for the Mamiya 300mm ULD. The Mamiya 300mm gives a much crisper frame with lots of more details. Case closed.

The same can not be said about the comparison against the Mamiya 105-210mm ULD zoom at 210mm. The crop of the zoom-image at 210mm is of course significantly more than both the Hasselblad 150mm+1.7x and the Mamiya 300mm ULD. I would believe that this disadvantage of the zoom-image would be too big to overcome. But I have a very hard time to crown the 300mm as a clear winner here. I would call it a draw. And that really shows what a stellar lens the Mamiya zoom is.

If you are in the market for a 300mm lens to your Hasselblad X2D (or Fuji GFX for that matter) and willing to use the e-shutter, the Mamiya 645 300mm f5.6 ULD comes highly recommended. Very cheap in the second hand market, small, lightweight and nice to handle. Excellent build quality and very good optical performance.



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