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cmar cmar is offline

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  1. cmar
    Hi Mark
    Very simple it is a full frame design ( quite an old one I believe) that has been "digitally enhanced" hence (DI) with some extra internal glass coating to cut down on the sensor reflections one sometimes sees on Film design lenses used digitally.
    Hence using the Pentax APS-C formula of approx 1.5 my 70-300 effectively becomes 105-450 in terms of field of view.

    Here is a link to a review of this lens (in Canon form) Tamron 70-300mm f/4-5.6 Di LD Macro 1:2 AF Review Where they go over this.
    I use it as well as a DA 55-300 but I have used Tamron lenses since the early 1980's and actually prefer Tamron colours.
    Best wishes
  2. Mark Freburg
    Mark Freburg
    Hello cmar! I just read the review you wrote about four years ago regarding the Tamron 70-300mm F4-5.6 AF Di LD Macro lens, model code A17. I just bought this lens recently as being made for digital SLRs, frankly assuming is was made for APS-C sensors (both my DSLRs use this sensor). I see by your review comments that this lens is a full frame lens, and you commented on the crop factor. I really can't find anything in the owner's manual to dispute that, or confirm it for that matter. How did you find out that information, if I may ask? Thanks much. --Mark

About Me

  • About cmar
    Sunshine Coast
    Real Name
    Pentax Cameras
    K-5, K-r, Q, Pentax Film SLRs
    Photographic Equipment
    ME Super + Winder MEII
    Pentax 50mm 1.7
    Tamron Adaptall2 80-200
    Tamron Adaptall2 28-80
    Tamron Adaptall2 500mm mirror
    Tamron 17-50 F2.8
    Tamron 10-24 F3.5-4.5
    Tamron SP 90 Macro
    Tamron 70-300 Di Macro
    Pentax Kr
    Pentax Q
    Pentax DAL 18-55
    Pentax DA 50-200
    Pentax DAL 55-300
    Pentax Q Standard Zoom
    Pentax Q Prime 01
    Pentax Q Fisheye
    Pentax Q Long Zoom
    About Me
    I'm a medical scientist who has always held an interest in photography, - I used to do a lot of microscope photography at work. Bi I really enjoy landscapes. I've only recently retired my film Pentax, which I bought new, and gone 21st century although I still use the lenses!
    Photography, Computers, Camping, 4WD Touring
    Medical Scientist


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