| Showing all 3 reviews by THoog | |
| Review of: Arsat Jupiter-36B 250mm F3.5 by THoog on Thu September 22, 2016 | Rating: 8 | View more reviews | |
Views: 35334
Reviews: 5
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I may have bought this lens for less than $50, shipping included. I think the previous owner was happy to pass along a "white elephant". I haven't done much with it, because the weight makes it almost unusable on Pentax DSLRs. As you can see from the optical diagram, the front third is one huge mass of glass, making it extremely nose-heavy and difficult to use hand-held. Optically, the lens is fairly sharp with (to me) pleasant bokeh. It does have a fairly long minimum focus distance (more than 3m/10 feet). Of course, the lens is all-manual, and it's Pentacon 6 format. To use it on a K-mount camera, you'll need a Pentacon 6 to M42 adapter (and an M42 to K-mount ring) or a P6-direct-to-K adapter, which may cost a little more, but adapters aren't hard to find.
The weight really demands a tripod, but the lens lacks a tripod foot. I haven't found any Pentacon 6 adapters with a built in foot. Using the camera as the tripod mount is awkward because so much weight is so far forward. I have found that an 81mm Canon 'C' type tripod ring/collar will fit perfectly in front of the aperture ring - which really is the only part of the lens where you could put a tripod ring. This puts the heaviest part of the lens directly above the tripod connection. How well this works depends on how heavy your camera body is. You will need a decent tripod that doesn't shake like a frightened puppy under the weight.
So who is the Jupiter 36B for?
- Well, Medium Format shooters, obviously. As fs999 shows, the lens gets excellent results adapted to 645.
- 35mm Full-frame or film shooters, possibly.
- APS-C is hard to justify on this lens - you are just using a small part of the image circle provided by all that glass. If you are going to stop down, you might as well get a slower 300mm zoom or prime.
If you are a student on a budget and desperate for longer glass faster than f/4.5, or just someone who likes to experiment (me), you can make this lens work, but you will have to work at it (and invest in a good tripod).
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| Review of: Sigma DC HSM (Art) 30mm F1.4 by THoog on Thu May 22, 2014 | Rating: 9 | View more reviews | |
Views: 77006
Reviews: 15
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If you are looking for a fast lens with "standard" Field of View on APS-C and HSM focusing, there aren't a lot of choices, and even fewer that weigh less than 500g/1 lb (my limit for use on a K-01). The Art 30 is a very good lens, and can get excellent results, but you need to be aware of its limitations. Wide open, in bright light or with high-contrast subjects, there is chromatic aberration/purple fringing even in the center. Corners are sharper than the older Sigma EX 30, although still a little soft at wide apertures (and CA adds to that).
It's kind of large for a walk around lens and not subtle at all with the hood installed. It is flare resistant enough to use without the hood even outdoors in bright sunlight.
I can confirm the slow AF/no AF problem on newer DSLRs, but it only seems to happen in 11-point/5-point auto-select AF mode. Using center point or select-point AF, the lens focuses as fast as any of my screw drive lenses. The K-01 does not have any problems with this lens.
Link to my (lengthy) review of the Art 30 in the SLR Lens Discussion section:
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/262745-my-sigma-art-30mm-f-1-4-dc-hsm-art-review.html | |
| Review of: Zenit MC Zenitar-K2 2/50 50mm F2.0 by THoog on Thu May 16, 2013 | Rating: 8 | View more reviews | |
Views: 41673
Reviews: 3
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The Russian MC Zenitar-K2 50mm f/2 is an interesting lens. It's one of the few examples of lens designers taking advantage of plastic molding and making a lens look like something other than a black metal can. The design goes back to the late 80s, but you can still buy a new one for less than $50. I bought it to use on my K-01 - they both combine unorthodox looks with surprisingly good performance (at a bargain price).
The plastic body is lightweight, but it does feels "plasticky". Two criticisms I have: (1) the plastic focus ring is slightly skewed on mine, so it hangs over by about 1mm on one side, and (2) when the lens is wide open, the spring that holds back the aperture lever rubs against the focus mechanism with a scrapy/springy sound. That spring may have to be replaced at some point (or it may just need a little break-in).
The word I keep finding myself using for this lens is "pleasant". It's sharp, but not super-sharp like a Zeiss. The bokeh is smooth and has a pleasing character (to my eye, at least). Wide open, I could find a little color aberration when pixel-peeping, but it wasn't there when stopped down. I tried the classic "bare branches against the sky" shot, and did not see any purple fringing.
If you enjoy shooting with something that looks different, then it's definitely a fun lens that gets good results - and for a NEW lens, the price is unbeatable.
The Zenitar-K2 and -M2s are the same basic lens; the K2 is K-mount (no A-contacts, so stop-down metering only), and the M2s is M42 screwmount.
     
f/8 and f/2: sharpness versus bokeh (both exposure adjusted in SILKYPIX for better comparison)  
100% crop example (a lousy example shooting into shade):
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