1. Reminder: Please use our affiliate links for holiday shopping!

What is the native magnification of the Panasonic 25mm, and extension tubes question.

Discussion in 'Native Lenses' started by colbycheese, Jul 14, 2015.

  1. colbycheese

    colbycheese Mu-43 Veteran

    378
    May 1, 2012
    Way up there.
    I have been getting in macro slowly in the past little while and i still have some questions i need cleared up. I know there is a formula (i just don't know what it is) that tells you the magnification the certain amount of extension tubes gives you. My question is, the main lens i use for macro until i get a macro lens is the 25mm panny. What is the ideal magnification for macro, and how much extension in mm do i need? Thank you
     
  2. dwig

    dwig Mu-43 Top Veteran

    622
    Jun 26, 2010
    Key West FL
    There is no such "ideal" magnification.

    You might checkout this page for information: https://en.wikipedia.org/wiki/Macro_photography

    There is an image down the page a bit that illustrates using extension tubes and give a formula. Note that any such formulas are accurate for lenses focused to their infinity setting. They remain accurate for other focus settings only with lenses that focus by moving the whole optical system as a unit.

    When using lenses that focus internally or by moving only a few elements there are other factors that need to be included and none of the needed data is ever available from the lens manufacturers. With these lenses the only way to find the magnification ratios when the lens is not set to infinity is by trial and terror.
     
  3. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    The macro abilities of the PL25mm are really pretty limited. Its maximum native magnification is just 0.11x. In fact, of the three native lenses in your signature, the PL25 offers the least magnification.

    Your options for extension tubes for use with electronic lenses (assuming you want to retain aperture control) are limited as well -- the only tubes with electronic contacts I have seen come in sets with 16mm and 10mm tubes. I have seen reports of issues with difficulty in maintaining a connection with both of the tubes stacked (though it can be done), so I wouldn't expect you would be likely to have good luck stacking multiple sets. This limits you to 26mm of maximum extension.

    By my seat of the pants calculations, 26mm of extension behind the PL25 will provide roughly a 1.15x magnification.

    If you really want to get into macro this seems like not the best way to go about it. I would suggest you look for a legacy macro lens or perhaps a reverse adapter for one of your existing legacy lenses.

    As far as the "ideal magnification" it really depends on the size of whatever it is you are photographing and how close you want (or are able to) get to the subject.
     
  4. piggsy

    piggsy Mu-43 All-Pro

    http://www.cambridgeincolour.com/tutorials/macro-extension-tubes-closeup.htm

    Note - I don't have this lens :D

    Native mangnification of the panasonic 25mm f1.4 seems to be 0.11x?

    You will need auto extension tubes for that lens since it seems to lack an aperture ring - the most common of these for m43 are sold as a 10mm and 16mm set - so 10mm alone brings you to 0.51x, 16mm alone brings you to 0.75x, and stacking them for 26mm brings you to 1.15x. Closest focus with both tubes is going to be kind of ridiculously close - 10.5cm from the sensor - then add a 63mm long lens, and 26mm long extension tubes gives you very very little room from the front element at 1.15x (~16mm, probably less in reality). 0.51-0.75x is probably going to be more comfortable :D
     
    • Informative Informative x 1
  5. tkbslc

    tkbslc Mu-43 Hall of Famer

    I would bet using some cheap manual tubes on one of your manual 50's would be a better solution. You won't have AF, but for high magnification macro that is a crapshoot anyway. Manual focus can be more reliable.

    50mm with a cheap stack of tubes from ebay gets you to about 1:1 with about 4" (10cm) of working distance. That's not much worse than the Oly 60mm Macro.
     
  6. dwig

    dwig Mu-43 Top Veteran

    622
    Jun 26, 2010
    Key West FL
    For most macro work, it is field of view and not magnification that is important. Magnification is merely a factor that, along with the size of the sensor/film, helps determine the field of view. With m4/3, a magnification of roughtly 0.5x yields the same FOV as a magnification of 1.0x does when using 35mmFF.

    For "macro wildlife" (e.g. bugs on a leaf), it is almost always best to use a lens with a focal length 2-4x "normal" (normal: FL=sensor diagonal or ~20mm for m4/3). Even longer lenses can be a good choice. Keep in mind that the effect of an extension tube is a matter of its length relative to the FL of the lens it is used with and not is absolute length. The longer the FL of the lens the longer the extension tube needs to be to achieve the same FOV. Using the longer lens will generally increase the distance from front of the lens to the subject, but this will vary with the optical design of the lens. Simple optical designs (e.g standard "normal" lenses like 50mm lenses adapted from 35mm cameras, ...) will generally leave the largest clearance between subject and lens. Complex zooms are usually poor choices.
     
  7. coffeecat

    coffeecat Mu-43 Top Veteran

    714
    Aug 4, 2012
    SW England
    Rob
    I have played with macro for quite a while, using mostly a legacy adapted MF 55mm lens and extension tubes. But the annoying thing for me was the very limited focus range, which meant I had to keep adjusting the distance between camera and subject (usually by moving the tripod). I have recently bought a cheap old MF dedicated macro lens and this has largely solved that problem, since it focuses natively from about 9" to infinity.

    Just another thing to think about.
     
    • Agree Agree x 2
  8. colbycheese

    colbycheese Mu-43 Veteran

    378
    May 1, 2012
    Way up there.
    so far the only frustration i have got out of this is the ultra narrow dof. I cant seem to nail a sharp focus on my subjects, even when using f/8. Edit: did some googling and apparently focus bracketing is a thing. How exactly does this technique work? Is it like hdr?
     
  9. piggsy

    piggsy Mu-43 All-Pro

    Kind of - annoyingly Olympus/Panasonic don't actually offer a way to do it automatically, and none of the cool toys for canon/nikkon are available. You are left with doing it manually and manually making a focus stack out of the resulting images yourself. On wireless supporting cameras the Olympus Share mobile app can be used to sort-of do it just as a program that can set an AF point (which is sometimes not entirely ideal for reasons) or be used as a remote shutter for triggering the camera without jostling it, but it's not quite the same.

    If you've googled it - it works just as you're seeing - you set MF mode and rock the camera forwards or backwards from the target, keeping the same point centered (though most programs will be a little tolerant of fractional mis-alignments or can cope with doing a stack that is also a panorama) and make salami slices of it that are in the DOF. Photoshop is fairly easy to use if you have it - load images to layers, edit > auto align layers, edit > auto blend layers, manually paint or point it to anything it messes up - or you can use whatever else.

    Oh and, F8 is nothing at all when it comes to macro F-stops - especially once you are at or past 1x! If you're stacking you're likely better off using the sharpest aperture and just using more DOF slices for the stack (for the 25mm - somewhere around f2.8-4). If you can't stack because it's a moving subject or a tripod is impossible - it's up to you to judge whether you are better off sacrificing overall sharpness to make the image work. If you look carefully at a lot of people's better macro work - it is not actually that concerned with getting maximum sharpness of the entire subject - just enough to get the action in the shot intelligible and deep enough so that anything past focus isn't obliterated blur wise.
     
  10. wjiang

    wjiang Mu-43 Hall of Famer

    I have a PL25, and a 10mm, 16mm, 21mm auto extension tube set. The native magnification of the PL25 is pretty poor. I don't recommend using extension tubes with the PL25 though, even with 10mm it brings the minimum focus distance too close to the front of the lens for my liking, making it easy to block light. The PL25 is also not the best lens for extension as it exposes all the flaws of having such a fast aperture. I get better IQ sticking my high quality legacy +1.6 and +3.3 achromatic converters on the front. The achromats also give a greater range of focussing ability than the extension tube for the same magnification for some reason.
     
  11. fredlong

    fredlong Just this guy...

    Apr 18, 2011
    Massachusetts USA
    Fred
    This is because diopters reduce the focal length of the lens which "increases" the extension giving you closer focusing. Since the focal length has changed the original focus throw is "longer" in comparison to the new shorter focal length.

    Fred