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P45-175 and Olympus tcon 17

Discussion in 'Native Lenses' started by anthonyrc, Oct 29, 2015.

  1. anthonyrc

    anthonyrc Mu-43 Regular

    55
    Feb 5, 2013
    Has anyone tried this combination? I have this screw on front "telescope" and have tried it on a variety of lenses over the years with mixed results. It works well on my Adaptall Tamron 90mm macro (72B), and on my Canon 70-200 f4L, (on APSC, vignets on FF) and I was really surprised at how well it did on the O12-50. Not so good on the P45-150 or 45-200
    As the 45-175 is internally zooming there would be no stress on an extending barrel, so any views?

    Tony
     
  2. wjiang

    wjiang Mu-43 Hall of Famer

    I had, tried on the 45mm, 40-150R and 45-175. Only worthwhile on the 45mm IMO to give an unwieldy ~75mm f/2. The extra extension to FoV beyond 150mm was inferior in IQ to cropping, in addition to confusing the IS and metering. Fringing was super bad.
     
  3. ijm5012

    ijm5012 Mu-43 Hall of Famer

    Oct 2, 2013
    Pittsburgh, PA
    Ian
    Yep, CA is pretty unbearable when shooting outside.
     
  4. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    I have the B-300, the old version of the T-CON. Teleconverts amplify the lens defects so it depends on the lens and aperture (I suppose this also applies to screw-in adapters).

    I have a few test shots with a Tamron 70-210 mix and matched with a 2x proper teleconverter. Here the B-300 shots (post processed):

    22572572175_87f63ec962_c.

    21949862224_300fa9d44d_c.

    CA can be bad but is quite easy to remove/minimize. I've seen weird color fringing in the oof zones. Minimum focus distance increases a lot.
    I plan to use mine where other options are not possible (with a 200/4 and a 135/2.8 in low light). I just did a quick upscale comparison on this shot and the teleconverter looks better (not very conclusive).

    No idea how OIS behaves with a similar adapter.
     
  5. anthonyrc

    anthonyrc Mu-43 Regular

    55
    Feb 5, 2013
    My 45-175 arrived today and with rain outside have been reduced to taking shots of my watch and union magazine. The 45-200 has gone in the post to its new owner but have the 45-150 as a benchmark. Initial impressions are that everything is as it should be and I couldn't resist the temptation to screw on the tcon 17. I'm not seeing any colour fringing and corners seem ok. In the absence of a 46-55 step up ring I am using two stacked rings which may have a bearing on performance. Early days though and I'll try to get some real world use tomorrow.
     
  6. wjiang

    wjiang Mu-43 Hall of Famer

    It's not that bad, it's just that cropping always seems to come out better at 175mm extension - the most problematic thing is the extra fringing with high contrast and the increased difficulty using the lens physically and as far as IS is concerned.
     
  7. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    I didn't thought about this: with adapted lenses you just set the combined focal length and you are fine. With a native lens I think there is no possibility to explain the mischief so the IBIS keeps working with the native FL being less effective.
     
  8. anthonyrc

    anthonyrc Mu-43 Regular

    55
    Feb 5, 2013
    I can't really get my head around how Panasonic's in lens IS compensates for focal length and whether adding a 1.7 front converter makes images 1.7x more blurred. Certainly the extra length may not gain more detail but along with the digital zoom offers the possibility of extreme focal length for video.

    Playing around with Oly's IBIS, focal length setting available for manual focus shows a very obvious effect especially if you forget to adjust when swapping from a 500 to 7.5mm lens :)
     
  9. wjiang

    wjiang Mu-43 Hall of Famer

    Good point about video, where cropping is problematic (unless you're cropping 4K to FHD). There's no way OIS or IBIS can compensate automatically since it doesn't know you put the TC on. And unfortunately setting IBIS focal length is only for dumb lenses which isn't the case here. That's one reason proper rear element TCs are more effective in the grand scheme of things, as they can communicate the focal length change via contacts.
     
  10. anthonyrc

    anthonyrc Mu-43 Regular

    55
    Feb 5, 2013
    If you need to fool a camera body that the lens is dumb then a slip of lens tissue on the contacts will do it. Reduces you to manual focus only and zoom by wire lenses will be "confused"