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Cosina ( Petri, Vivitar VMC) 35mm f2.8 Cosinon W MC

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4 26,851 Thu March 21, 2019
Recommended By Average Price Average User Rating
75% of reviewers $26.67 8.25
Cosina ( Petri,  Vivitar VMC) 35mm f2.8 Cosinon W MC

Cosina ( Petri,  Vivitar VMC) 35mm f2.8 Cosinon W MC
Cosina ( Petri,  Vivitar VMC) 35mm f2.8 Cosinon W MC
Cosina ( Petri,  Vivitar VMC) 35mm f2.8 Cosinon W MC

Compact 35mm moderately wide angle lens on film that approximates to a standard lens when used on a crop sensor DSLR.
This lens dates from the 1970's and the PK bayonet (also found as M42) is black anodised (pic 3). This means that there won't be electrical contact to the mount on a dslr, green button won't work (on most models), and the lens probably won't stop down. Solution is to create a contact, the lens in pic 3 has had the anodising removed to allow the data (#6, at the half past position on the camera) contact and the adjacent contact to connect.
Also found as a Petri (review below by eddybe), and a Vivitar (pic 2) 9xxxxx serial (see komine, tokina made viv 35mm under vivitar primes ) , PKM and other mounts of the era.

Optics: ? 5elements
Filter: 49mm
Aperture: f2.8 - f22, single stop clicks
Iris: 6 blades.
Focus : ~100 throw, anti pentax rotation.
Close focus: 40cm
Weight: 210g

See for a comparison between this lens and the Pentax K 35mm f3.5.
Mount Type: Pentax K
Price History:

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New Member

Registered: February, 2019
Posts: 12

1 user found this helpful
Lens Review Date: March 21, 2019 I can recommend this lens: No | Price: $25.00 | Rating: 6 

Pros: Small and well made
Cons: Flare and blurry edges
Sharpness: 6    Aberrations: 6    Bokeh: 7    Handling: 10    Value: 7   

I have the Cosina Cosinon f2.8 Auto MC in a very clean mint version. Lovely to focus as the turning circle is very small. Very easy to use. It feel magnificent and the build quality is very tactile in terms of mechanics. Silly phrases like "buttery smooth" focus can be applied. The aperture runs from 2.8 to 22 and has half-clicks to f16. Very well built and really smooth to use. It has a horrible little fiddly auto/manual switch that is very awkward to adjust on a camera. Because it's not "fashionable" you can find these very cheap, and that is it's saving grace as there are many better 35mm M42 screw-in lenses around in terms of image quality range. That's right, this has great build quality, but very ordinary image quality. It is fairly sharp in the centre 30% from f5.6 through to f16 in most situations, but it's never spot on outside of the centre area and the immediate area beyond. Being a f2.8 small aperture lens will make some people assume it's superb - as many rave on about small aperture mechanics with fetish-love - but it's not special at all wide open. Use with a hood as it catches flare something terrible, even in low light. The rather distant 0.5 meter close up maximum is a bit far away for close work. Some nice bokeh because of the edge fuzz/blur. Quite ordinary contrast levels. Really quite poor edge focus on all f-stops. Overall, this is a fair-to-good lens that can produce some very good images, but it's never excellent. Best up close to about 12 feet. Beyond about 20-30 feet the quality deteriorates. It sort of fits the bill for urban work where you want a bit of flare and edge roughness with associated blur. Not for landscape shots, for sure.
New Member

Registered: May, 2015
Posts: 2
Lens Review Date: June 5, 2015 I can recommend this lens: Yes | Price: None indicated | Rating: 10 

Pros: sharp edge to edge full open
Cons: non realy
Sharpness: 9    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 10   

I own this lens for about three decades , give or take a few years. Picked it up together with a K1000. Mine is marked with the petri brand but it is in fact a Cosina.
Took some time to find out. . After all i find it to be a very pleasant lens for street fotografi. Very sharp and very light. I do no know what i payed for it in the days , but if you can grab one, do not doubt yourself and take it.
New Member

Registered: December, 2012
Posts: 1
Lens Review Date: December 31, 2012 I can recommend this lens: Yes | Price: $25.00 | Rating: 8 

Pros: price, solid construction, small
Cons: no A setting, manual only
Sharpness: 8    Aberrations: 8    Bokeh: 8    Handling: 7    Value: 10   

After several years of using zooms (particularly a Tamron 18-250) I become interested in the old zoom v prime debate. So I dug out my Chinon 50mm f1.9 which I had bought decades ago with a CP7m but never used. It was still in the orignal box, untouched, no dust or fungus, nothing! All I can say is "wow, I love it" but that's for a separate review.

So i was hooked, problem is that on APSC the 50mm is great for portraits but just too tight for more general shots so I decided to look for a 35mm (closer the old standard lens view). The highly regarded Pentax f3.5 and others were going for crazily high prices on ebay so I looked for an alternative. There aren't many reviews around for this Cosina lens, one of which showed it to be the worst from a choice of several 35mm lenses from different manufacturers. Anyway, this one was available for 25 so I decided to take a chance.

My findings are more in line with the reviews/links on this site. I'm currently using it on a K100d but can still identify differences between it and the Tamron zoom.

Key points;

Sharp at f2.8, better at f4 and the sweet spot for me is f5.6. F8 still ok but slight fall off in sharpness after that (but still ok).

Central definition is better than my zoom.

Edge definition is better than my zoom.

Contrast is good but not quite up with the very best.

CA control seems to be very good, I've not managed to produce any photos where it's obvious, even pixel peeping.

I did manage to produce some flare but had to get the sun in the top of the picture to induce it.

Bokeh seems ok to me. It's only a 5 blade iris but backgrounds aren't too busy and remain relatively smooth. I did manage to produce some weird effects on one picture, like discs or coins dropped in a pile overlapping each other but I've seen that several times before.

Exposure was fine - Use manual mode. Set the aperture on the lens then just before shooting press AE lock to meter/set the shutter speed. (Green button on some cameras). As the AE lock button stops down the aperture the metering is always fine (remember though to point at your subject as it's centre weighted metering)

Focussing - Tip - The rear plate of this Cosinon lens is black anodised and non conductive therefore the body contacts do not detect that a lens is present and the focus confirmation doesn't work. Take some sand paper or emery cloth and lightly remove just enough of the anodising in line with the bottom contact. Voila, focus confirmation works! Focussing is not the K100d's best feature in my view. Despite me making changes in the hidden menus to fix the front focussing problem I still think the distance of the focus screen and sensor from the lens must be slightly different. That's a problem with the camera and not the lens. The focussing system confirms focus on the edge of the depth of field. Depending on which direction you change focus from ie come in from distance or go out from close up you'll get a different focal distance confirmed. It's something you quickly get used to and move the lens back and forth a touch until you feel you're in the middle. I only use the focus confirmation beep as a backup, I've found that you still need to trust the focussing screen not the beeps.

This all sounds a bit laborious but actually it's no problem at all. I quickly got back into the swing of using a manual lens and can compose/focus/meter in just a few seconds.

I was really surprised at how good this lens was, I expected it to be a bit of a duffer. It's not the best out there but if you're doing enlargements it's a step up from a zoom lens. Not bad for 25.

New Member

Registered: February, 2012
Posts: 15
Lens Review Date: July 15, 2012 I can recommend this lens: Yes | Price: $30.00 | Rating: 9 

Pros: Sharp wide open, high contrast, pleasing natural colours
Cons: Focus goes opposite way to Pentax standard.
Sharpness: 10    Aberrations: 10    Bokeh: 8    Handling: 8    Value: 10   

In size and construction, this lens most closely resembles a Pentax A 50 mm f1.7, although the focus turns the opposite way to the Pentax standard, and it has no A setting. I bought it to give me f2.8 at 35mm, before I bought the Tamron AF 17-50mm F2.8 XR LD Aspherical IF SP.

At f2.8 I think it is superior to the excellent Tamron zoom, and it is also superior to the two ancient preset 35mm f2.8 lenses I bought for Video use. But I don't make much use of it.
Add Review of Cosina ( Petri,  Vivitar VMC) 35mm f2.8 Cosinon W MC

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