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Showcase Computar 75mm f/1.4 CCTV

Discussion in 'Adapted Lens Sample Image Showcase' started by DeeJayK, Jul 5, 2012.

  1. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    I recently picked up this lens and so far I'm pretty impressed with the results. As with most large aperture lenses it's a bit soft wide open (good for portaits), but it sharpens up pretty well when stopped down to f/2 or f/2.8. It exhibits (to my eye) a quite pleasing bokeh.

    Unlike most other c-mount lenses I am familiar with (e.g. the Fujian 35mm f/1.7) it is fairly large and heavy. It is roughly the same diameter as the Olympus kit lens and it uses 58mm filters. On my (not hyper-accurate) kitchen scale it weighs in at about 380g; it feels roughly similar in heft to my Konica 57mm f/1.4 when both lenses are connected to their respective adapters.

    Frankly I'm a bit surprised that no one else here seems to be using this lens yet.

    Here are some sample images:

    https://www.mu-43.com/gallery/data/500/20120703_7036144.jpg">

    [img]https://www.mu-43.com/gallery/data/500/20120703_7036095.jpg">

    [img]https://www.mu-43.com/gallery/data/500/20120703_7036087.jpg">

    My copy is branded "Computar" but I've seen extremely similar looking lenses sporting several other names, including Navitar and Apollo. I've also seen a Navitar 75mm f/1.3 version. I've seen other c-mount 75mm lenses with similar apertures branded Cosmicar and Pentax that appear to be of an entirely different lens design.

    Here are some images of the lens on my E-PL1 (click images to enlarge):
    [URL="http://takenwithm43.com/mu-43/Computar75/20120711_1040454.jpg"][ATTACH=full]215595[/ATTACH]250>[/URL] [URL="http://takenwithm43.com/mu-43/Computar75/20120711_1040458.jpg"][img]http://takenwithm43.com/mu-43/Computar75/20120711_1040458.jpg250>[/URL] 20120711_1040460. 250> 20120711_1040461. 250 title="Note the aperture/focus marking aligned on the bottom of the lens when mounted">
    The front element is quite large and quite convex. I've ordered a hood to minimize flare as well as to provide a bit of protection.

    Here is the lens with the adapter attached (sandwiched between the Olympus 14-42mm and 40-150mm for scale):
    [​IMG]250> [​IMG]250>
     
    • Like Like x 5
  2. thearne3

    thearne3 Mu-43 Top Veteran

    807
    Jan 28, 2010
    Redding, CT USA
    First I've ever heard of it...have the 12.5mm and have had the 25mm. A quick search on Google and ebay doesn't show anything...tell/show us more!
     
    • Like Like x 1
  3. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    Unfortunately, I don't know a whole lot about the lens. Here are some links I found through a Google search:
    Here's the eBay listing for my recent purchase (for as long as that does anyone any good).

    Unfortunately I don't have a decent picture of mine on my camera, but I'll post one here (along with some more images) when I can.
     
  4. ryanlogic

    ryanlogic Mu-43 Veteran

    293
    May 23, 2012
    Antakya, Turkey
  5. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    Looking at those images, the Cosmicar is pretty clearly a different lens than the "Computar" I have. Mine looks fairly similar in shape to the Pentax lens, but that is not the same lens either as mine has the focus and aperture rings swapped (aperture ring is nearer the front of the lens) and mine has a fairly convex front element while that on the Pentax appears much flatter.
     
  6. ryanlogic

    ryanlogic Mu-43 Veteran

    293
    May 23, 2012
    Antakya, Turkey
    Yea, I posted that before I saw the reply. That Pentax lens looks interesting...

    Is it the same mount?
     
  7. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    Yeah, I agree the Pentax would be worth a look (or at least a thorough Google search).

    These are all C-mount lenses which were originally designed for things like security cameras. The big advantage of these lenses is that since they were not designed with SLRs (with their mirrors between the lens and sensor), the register distance (distance between the back of the lens and the sensor) is much more similar to that of :43: resulting in very thin adapters.
     
  8. mister_roboto

    mister_roboto Mu-43 Top Veteran

    637
    Jun 14, 2011
    Seattle, WA, USA
    Dennis
    Neat- I have a soft spot for the no-name CCTV lenses, they're my favorite for playing with.

    I have a 25mm + 35mm, and I only recently found out about a 50mm- and this is the first I've heard of the 75mm. Out of curiosity, how much?
     
  9. phrenic

    phrenic Mu-43 All-Pro

    Sep 13, 2010
    Interesting! Thanks for sharing. A little cheaper than the new Oly75mm 1.8 I imagine. ;)
     
  10. ryanlogic

    ryanlogic Mu-43 Veteran

    293
    May 23, 2012
    Antakya, Turkey
    any drawbacks?

    IQ?
     
    • Like Like x 1
  11. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    I spent about US$67. Not sure if that's a great price. I've seen other similar lenses go for around US$100.

    Sent from my Android phone using Mu-43 App
     
  12. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    I haven't used it a whole bunch, but so far I haven't noticed any huge negatives other than some lens flare. My biggest gripe is that it ends up sort of upside-down on my adapter (that is, the aperture and focus marks are on the bottom of the lens). That may be more a function of the particular adapter I have a the other c-mount lens I have (the Fotasy/Fujian 35mm 1.8) exhibits the same problem. That's more of a nuisance than anything else and it certainly doesn't impact IQ.

    Sent from my Android phone using Mu-43 App
     
  13. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    Here's another sample image. Note that the bokeh appears to be exhibiting some "swirlyness" in this one.

    20120710_1040414. 768>

    I've also updated my [post=282836]initial post on this lens[/post] to include some photographs of the lens itself and an expanded description.
     
    • Like Like x 2
  14. ISO1600

    ISO1600 Mu-43 Regular

    27
    Aug 17, 2012
    Abilene, TX
    Chris
    Does this lens have click-stops?
     
  15. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    Yes, it does, although at least on my particular example they are pretty light (for lack of a better way to explain it).
     
  16. yktay2

    yktay2 Mu-43 Regular

  17. ISO1600

    ISO1600 Mu-43 Regular

    27
    Aug 17, 2012
    Abilene, TX
    Chris
    I found one of these on Powell's surplus the other day for $139, they accepted my offer of $135. A little higher than $67, but much cheaper than eBay!

    I can't wait! This will by my concert/portrait lens
     
  18. madmaxmedia

    madmaxmedia Mu-43 Veteran

    335
    Feb 20, 2010
    Wow, this lens looks delightfully creamy!

    Can anyone comment on how large the circle of sharpness is for this lens? At this focal length, you probably have head and shoulder pics that take up a lot of image area.

    I'm surprised this is the only Computar lens in the archive. I am considering this one, or the 50mm. I would probably prefer the 50mm, but only if the bokeh is like this...
     
  19. Crdome

    Crdome Mu-43 Hall of Famer

    Sep 11, 2011
    West Central Indiana
    Chrome
    Keith -With the 75mm FL it seems like it ought to provide full sensor coverage. is that correct?

    I notice the aperture and FL markings are located toward the bottom of the lens typical with c-mounts. This c-mount adapter is adjustable so you can rotate the lens to the correct top position then lock it in place. I've not used it but have read great things about it. I've had most of my c-mount legacy lenses CLAd and adjusted to the correct position during the process
     
  20. RDM

    RDM Mu-43 All-Pro

    I have the exact same lens and I also have one of the very 1st C-mount adapters produced, I purchased it online back in 2010 when I found out that I could use my C mount lenses with one..
    After seeing your alignment problem I do not feel so bad about mine. The Focus Line mark on my copy, is at about the 2:00 position, when looking at the front of the lens mounted on a camera. I was bothered by this but not so much after seeing your post.. I see now it could be worse. . . lol
    Also i was worried about flair too , but I have pit on it, a classic Vivitar VMC (Vivitar Multi Coated) Skylight Filter. I have not noticed any flair on my photos yet.

    Holey crap! I happen to have two of these lenses.
    DO you think I could sell one for $135.? Are they really in demand?


    Hope you dont mind me fielding this question, but Oh yea @Crdome. Fully covered no darkening at all . It should even fully cover a an APS-C sensor like NEX.
    I bet it would even cover the 'Full Frame' sensor NEX mount camera too. I have seen some other 75mm c-mount lenses converted to be used on Leica ranger finder cameras, that use type 135 film, too and they fully cover.