Pentax 645, should I get 150mm or 200mm for portraits????

Discussion in 'Medium Format Cameras and Accessories' started by harlequin, Mar 7, 2018.

  1. harlequin

    harlequin Member

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    Dear APUG Members,

    Finally got Pentax 645 back from repair, I want to focus on high quality portraiture and my 75mm wont cut it, so I am looking into the 150mm and 200mm lenses as they are reasonable and look well made, coatings etc.focus is nice and smooth on both units.....

    a) Is the 150 more for head and shoulders? I don't know the 35mm equivalent.
    b) would the 200 flatten the perspective to the point where just subject eyes in focus?
    c) If anyone has sample shots taken with these lenses, I would love to see them.
    d) Bokeh is a new term to me, but which lens would probably give the best "knock out the backround" effect.
    e) would the 120Macro be a consideration for this???

    Many Thanks for your feedback and responses...

    Harlequin
     
  2. MattKing

    MattKing Subscriber
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    The answer depends on you.
    What working distance do you prefer to use for what types of portrait? What types of portraits are you planning - head shots, full length portraits, head and shoulders, sitting portraits?
    Choose the working distance and preferred crop, and that will determine the focal length that fills the frame.
    Perspective has nothing to do with depth of field - nothing to do with whether the ears and nose are in focus when the eyes are. Perspective is determined by working distance - not lens choice - and depth of field is determined by effective magnification and aperture choice.
    I like working with an 85mm lens for 135 film - rarely tight head and shoulders, more commonly something with more space around. In the world of 6x4.5, that is probably closest to 125mm, but the different aspect ratios complicate the question.
    FWIW, in 6x4.5 (Mamiya) my longer lenses are 110mm and 210mm. My "standard" lens is probably the 55mm, but I do have an 80mm macro.
    This (self portrait) was shot with the 110mm (IIRC):

    upload_2018-3-7_9-8-56.png
     
  3. Eric Rose

    Eric Rose Subscriber
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    It totally depends on how you "see" and what "look" you want in the final image. Try them both and see which one fits your style and vision. If you want to stay friends with your female portrait subjects stay away from a macro lens.
     
  4. pentaxuser

    pentaxuser Subscriber
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    A good factor to use to get the equivalent of a 645 lens is 0.62 so a 150 for a 645 is about 95 in a 35 mm camera. It is worth reading the lens reviews on the Pentax Forums site. Membership is free. An awful lot of the stuff there is about D Pentax camera but the lens reviews cover 645 analogue and it is of course specifically Pentax

    pentaxuser
     
  5. wiltw

    wiltw Subscriber
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    35mm format 'equivalence' is so biased by the traditional use of the diagonal, when format aspect ratios are so different! Crazy to think of long aspect ratio, when 135 gets triimmed by 17% to fit the 10" frame length of the 8x10 frame!.

    I use the frame short dimension as the basis for 'same AOV' (same scene width is captured) in formats at identical camera postiion..
    • 100mm used for head and shoulders for 135 = 4.167 * the frame short dimension.
    • 4.167 * 43mm = 180mm
    Use of 150mm with 645 will have you standing 17% closer, so comparably tight framing would entail being at a distance which is a tad too close for good facial perspective, Being at 7.5' rather than a 9' shooting distance and getting that facial perspective. For that reason I would opt for 200mm, as that is only 11% more shooting distance than 180mm.

    Bronica made a 180mm FL lens for its ETRSi for that better facial perspective reason.

    Using the short dimension of the frames, 85mm FL for 135 format is like using 150mm on 645 format. So if you prefer the looser framing of 85mm, you would like the 150mm FL on 645

    Matt was 100% right about it being all about the working distance preferred. It gives you the right facial perspective to be 8-10' away from your subject. It puts you conveniently close to be able to quickly adjust pose and get back to your camera without short hikes.
     
    Last edited: Mar 8, 2018
  6. tomfrh

    tomfrh Member

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    I have the 150 3.5, the 200, and the 120 macro

    As a general portrait lens id go with the 150mm. It’s roughly 100mm equivalent, give or take, and it’s a nice light sharp lens.

    F3.5 is equivalent to about f2.2, so it’ll blur the background ok.

    The 200 is akin to a 135mm in 35mm format. It’s a bigger lens. Use this if you want longer working distance.

    The 120 is quite big lens too. Unless you want macro lens I’d take the 150
     
  7. adelorenzo

    adelorenzo Subscriber
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    There is also the 135mm leaf shutter lens to consider, especially if you intend to use flash.
     
  8. pentaxuser

    pentaxuser Subscriber
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    Good point. It might be worth adding "if you want to use flash at a range of shutter speeds " Other non-leaf shutter lenses lenses will only give 1/60th I think.

    pentaxuser
     
  9. Dennis-B

    Dennis-B Subscriber
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    My preference at the 6x4.5 for head and shoulders would be the 150mm. It's roughly 2x normal, which is "preferred" in the older schools of portraiture.

    That preference aside, you may also want to consider adding the 200mm. The 200mm will foreshorten the image a bit, and if someone has a "longish" nose, it will work to make that feature a bit less obvious.

    You could also consider the Pentax 150-300 f/5.6. You have a bit of flexibility with this choice, and if you're stopping down to f/11, etc., you should have adequate sharpness. I'm not a big fan of zooms for portraiture, but if you're looking for an economical compromise, this would work.
     
  10. Alan Gales

    Alan Gales Subscriber
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    The longer the lens the flatter the perspective. What looks best all depends upon opinion.

    Also consider working distance. The longer the lens the more you need to back up. If you shoot in a studio or outside there is no problem. It can get pretty cramped in someone's living room with backdrops and studio lights. I have to rearrange furniture in my little house. :smile:

    Why not try several lenses. If you buy right on Ebay and decide to later sell then you won't lose much money at all. Maybe just what you paid for shipping. What little you lose just consider a cheap rental fee.
     
  11. OP
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    harlequin

    harlequin Member

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    Many Many Many Thanks for your responses!

    Looks like I will start with the 150mm and add a 200mm shortly afterwards
    if the 120 Macro wasn't so much more $$ I would probably entertain that as well.

    Matt King, A Winnipeg sized Thank you for the sample shot....

    Harlequin
     
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