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Just a curious question about prime lenses

Discussion in 'Native Lenses' started by sin77, Jan 15, 2012.

  1. sin77

    sin77 Mu-43 Veteran

    243
    Dec 9, 2011
    Singapore
    Why can't it have OIS for Panasonic system?

    Is it technically not possible?

    It is a shame that an f3.5 can achieve the same stability as an f1.7 when OIS is turned on. :frown:

    The only reason to buy f1.7 is just mainly because of the shallow DOF.
     
  2. flaxseedoil1000

    flaxseedoil1000 Mu-43 Regular

    102
    Mar 10, 2011
    You mainly need it with longer lenses.

    Not needed with the 20mm.

    Have not had an issue with the Oly 45mm on my GH2 and I don't have the steadiest of hands.
     
  3. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    There are two equally valid reasons for a fast lens:
    #1 depth of field as you suggested
    #2 shooting in low light

    If you have ever tried shooting in a dark room without flash and a slow lens you quickly find out that you can't. Even if you have a tripod the images of people will be blurred because the slightest movement shows up. Granted you can boost the ISO but that will cause noise in the image{although the cameras are getting better and better all the time in this respect}.
     
  4. sin77

    sin77 Mu-43 Veteran

    243
    Dec 9, 2011
    Singapore
    for low-light, ie low shutter speed, isnt it compensated by OIS? And we are talking about 2 to 3 stops of light, right? The shortfall will be the motion blur of the subject though.
     
  5. m1pui

    m1pui Mu-43 Veteran

    257
    Dec 30, 2010
    Sunderland, UK
    I was just about to say similar.

    OIS compensates for your shake, not the subject.

    I could take a picture of an apple on a table in a dark room at f1.7 without OIS & f3.5 with OIS and they would probably both work out fine. Try the same with the apple hanging and the shutter speed almost certainly won't be fast enough at f3.5 to freeze the apple but the OIS could allow, for arguments sake, the static/stationary table to not be blurred
     
  6. sin77

    sin77 Mu-43 Veteran

    243
    Dec 9, 2011
    Singapore
    I would probably buy 12-35x with OIS and give 20/1.7 a miss.
     
  7. m1pui

    m1pui Mu-43 Veteran

    257
    Dec 30, 2010
    Sunderland, UK
    But why though?

    If you wanted a fast lens the 12-35 isn't going to cut the mustard.

    If you want a zoom lens, then the prime isn't really an option.

    Personally I think a fast lens is more use than OIS. Obviously the ideal would be a constant aperture zoom. I was buying a lens for my 500D a couple of years ago and had the option of, I think it was, the Sigma 17-70iS or a 17-50 f2.8 (no is). I went for the IS lens and I sorely regret it now
     
  8. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    I agree, there's no replacement for a fast aperture. IS is nice, but overhyped.

    Of course, when you have an Oly body and get IS as a bonus, available for any lens you mount including legacy lenses... well, you can't complain about that! =D
     
  9. sin77

    sin77 Mu-43 Veteran

    243
    Dec 9, 2011
    Singapore
    Zoom lens is very versatile. I don't have to change among 3 prime lenses during a walkabout, party or event. If I'm looking at 20/1.7, it is not even one stop of light better than f2.8. I can sacrifice some bokeh for a stabilised shot.
     
  10. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    Actually, it's more than a stop of light better. f/1.4, f/2, f/2.8, and f/4 are all full stops.
     
    • Like Like x 1
  11. fredlong

    fredlong Just this guy...

    Apr 18, 2011
    Massachusetts USA
    Fred
    To answer the OP's original question. The Panasonic system can and does have OIS. The system is built into lenses, just not all lenses. Stabilization can be useful with relatively short and fast lenses. On my old Olympus E600 I could hand hold a 50/1.8 at 1/10 sec. The best I can do on my Panasonic G2 is about 1/30.

    Fred
     
  12. ~tc~

    ~tc~ Mu-43 Hall of Famer

    Oct 22, 2010
    Houston, TX
    The PL45/2.8 has IS, so not only CAN they, but they do and have done.

    X2 for no replacement for aperture, especially considering our sensor size/DOF challenge. A whole lot easier to stop down a f/1.7 lens to f/4 than open up an f/4 lens to f/1.7 ...
     
  13. sin77

    sin77 Mu-43 Veteran

    243
    Dec 9, 2011
    Singapore
    Thanks, Ned. I was pretty confused with stop of light when it comes to aperture size. Shutter speed measurement is easier though. Now I have a great deal to think about my next fast lens.

    And also thanks to ~tc~ for pointing out that PL45 comes with OIS despite being a prime and a macro lens; and I own one. :redface:

    So why can't Panasonic be nice to its consumers and have all the lenses stabilised? Olympus on the other hand really stands to gain, but too bad, their sensor is mediocre at this juncture.
     
  14. GaryAyala

    GaryAyala Mu-43 Legend

    Jan 2, 2011
    SoCal
    "Why can't it have OIS for Panasonic system?"

    It can, should the manufacturer deem it marketable.


    "Is it technically not possible?"

    Yes, should the manufacturer deem it marketable.


    "It is a shame that an f3.5 can achieve the same stability as an f1.7 when OIS is turned on."

    OIS only affects/stabilizes the camera end, not the subject end. If the subject is moving it may be blurred with OIS while all of the stationary elements of the image will be sharp. With a fast lens one may be able to stop action and have a proper exposure in low light (at the expenses of DOF).


    "The only reason to buy f1.7 is just mainly because of the shallow DOF."

    That is one reason, another is design, it is a pancake lens so it is very tiny and not obtrusive. It is very sharp, as a general rule primes are sharper than zooms. Many of your better photographers use primes because primes deliver a better Image Quality, (granted sometimes the difference is insignificant), and generally a faster AF. I wish all my lenses had IS, but a big aperture is useful all the time ... OIS is useful only some of the time. There are many techniques and hardware that can compensate for lack of OIS ... not much one can do about aperture and DOF.

    I think it is all about marketing. To toss OIS on the 20mm would probably make it no longer a pancake and drive up the cost causing a drop in sales. Panasonic probably felt that a less expensive pancake would have greater sales appeal than a more expensive OIS non-pancake.

    G
     
    • Like Like x 1
  15. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Dara
    It's a matter of tradeoffs. OIS involves adding additional elements and motors. That not only raises the price, but it requires larger and more complex lens designs. For lenses that are designed primarily to be small like the 2 pancakes, that's a serious drawback.

    DH
     
  16. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    Here's my little list of equivalent EV stops which may help clarify it a bit... every step in either aperture, shutter, or ISO is a full stop and will have the equivalent effect on exposure as changing any of the other values:

    EV Full Stops (brightest to darkest)

    Aperture: f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32
    Shutter: 1s, 1/2s, 1/4s, 1/8s, 1/15s, 1/30s, 1/60s, 1/125s, 1/250s, 1/500s, 1/1000s, 1/2000s, 1/4000s
    ISO: 12800, 6400, 3200, 1600, 800, 400, 200, 100, 50

    ie, going from f/2.8 to f/2 will brighten the image as much as going from 1/15s to 1/8s, or from ISO400 to ISO800.
     
  17. ~tc~

    ~tc~ Mu-43 Hall of Famer

    Oct 22, 2010
    Houston, TX
    Just to add to Ned's post, a "stop" equates to making the image twice as bright. With shutter speed and ISO, it's pretty obvious, as all the numbers double (periodically, they are rounded off)

    The f/stop one is a big harder because it goes by the area of the aperture opening, but f/stop is defined by the diameter (focal length/diameter of opening). Since area is pi*d^2/4, you end up with a sequence of f/stops defined by powers of 2. As long as you are on the "full stops" scale Ned has listed, it's not so bad, but can be really difficult when you end up with weird apertures from variable zooms.
     
  18. carpandean

    carpandean Mu-43 Top Veteran

    827
    Oct 29, 2010
    Western NY
    Sometimes, it's even the difference between getting a lock and not. In real low-light situations, a smaller aperture lens with IS may hunt and not find a lock, while the larger aperture without IS finds it. It's a simple consequence of less light reaching the sensor.
     
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  19. flash

    flash Mu-43 Hall of Famer

    Apr 29, 2010
    1 hour from Sydney Australia.
    Gordon
    Panasonic lenses can and do have OIS. But with regard to the 20mm.
    1. Where the hell would you put it? It's a pancake lens.
    2. It would cost more.
    3. Its ability to focus as closely as it does would be compromised.

    Of course if Panasonic had been smart enough to put IS in the body it wouldnt be a problem. And we'd also get an orientation sensor to boot (which is totally unforgivable IMHO).

    Gordon
     
  20. RT_Panther

    RT_Panther Mu-43 Legend

    May 4, 2011
    Texas
    Counter-point:
    We shot film for years without any type of stabilization :smile:
     
    • Like Like x 1