zoom at 150mm vs. 75 f/1.8 cropped

Discussion in 'Native Lenses' started by Rudy, Jan 27, 2013.

  1. Rudy

    Rudy Mu-43 Veteran

    449
    Jan 24, 2013
    Oakland, CA
    The 40-150 zoom seems decent enough, but I was wondering how the 75 f/1.8 cropped down to a 150 mm view would compare.
    Does anyone have both of these and could post some comparison pictures and/or opinions. I'm only interested in sharpness here, so a brick wall would be fine. There are obviously other thing$ to consider, but if the cropped image is just as good then carrying the zoom would make little sense if you had both...
    Rudy
     
  2. David A

    David A Mu-43 All-Pro

    Sep 30, 2011
    Brisbane, Australia
    I don't have any direct comparisons but one of the reasons I bought the 75 was to get the speed for shooting birds and I was prepared to crop. The following image is somewhere around a quarter to a third of the frame wide so it's equivalent to something closer to 225mm than to 150mm:

    Mynah_1_of_1_.

    Take a look at the water drops falling from the bird's feet back to the water surface.

    Cropping isn't ideal, I'd rather have a much faster, longer lens and be able to avoid it. Still, if you aren't going to make really huge prints (cropping to a third of the dimensions gives you 1/9 of the pixels so that crop is less than 2 MP of the 16 MP frame) the 75 is certainly sharp enough. Ultimately it's going to depend on how you use the images you crop, and how and at what size you view them. That one is sharp enough for me to happily display on a retina iPad screen which is as large as I show it to most people. YMMV.
     
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  3. Savas K

    Savas K Mu-43 Top Veteran

    784
    Jan 10, 2013
    Agree with David as it pertains to use of the image as the determinant between using a zoom versus a long prime. A sharp copy of 75mm can act as a zoom of sorts via cropping given it's rendition of the scene.

    Cropped image:
    p1378082134-6.


    Screenshot of the crop in DxO:
    p1400761576-4.
     
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  4. mkee

    mkee Mu-43 Regular

    122
    May 9, 2012
    Long Beach CA
    This shot was cropped about the same as Savas' one.

    <a href="http://www.flickr.com/photos/34870254@N03/8397814553/" title="P1190071 by fm289302, on Flickr"> 8397814553_2fbbbf9692_c. "800" height="600" alt="P1190071"></a>
     
  5. b_rubenstein

    b_rubenstein Mu-43 All-Pro

    Mar 20, 2012
    Melbourne, FL
    I have both lenses. Making a choice only on the basis of sharpness, in this case, misses 90% of the difference in the lenses. The analytic, measurement lens reviews, along with my experience, is that the 75/1.8 is not more than twice as sharp as the 40-150 at 150mm (which is what it would have to be).

    Refer to the Blur Indices here:

    75/1.8

    40-150/ 4-5.6
     
  6. LeoS

    LeoS Mu-43 Top Veteran

    517
    Aug 6, 2012
    This one is 100% crop of a picture taken with 75mm with zero adjustments (notice the 'reset settings' on the history and crop area in the navigator):

    DhUgAZl.
     
  7. Jonathan F/2

    Jonathan F/2 Mu-43 Hall of Famer

    Aug 10, 2011
    Los Angeles, CA
    I agree with Bruce, don't get the 75mm to crop into. Get the 75mm for lowlight and shallow DOF advantages. If you need a fast 150mm, wait for Panasonic to release the 150mm 2.8. :wink:
     
  8. Rudy

    Rudy Mu-43 Veteran

    449
    Jan 24, 2013
    Oakland, CA
    As I mentioned in my original post there are many other things to consider.
    The shallow DOF is the main reason for me to get prime lenses over zooms. So the question is more about how closely spaced they should be to not worry much about cropping a bit.
    Zooms are convenient, but at f/5.6 on an MFT the DOF is just too deep.
    I guess I'm trying to talk myself into getting the 75 and I already know what you guys will be telling me and it's no help on my wallet:rolleyes:
    Rudy
     
  9. David A

    David A Mu-43 All-Pro

    Sep 30, 2011
    Brisbane, Australia
    I never suggested that the 75 was twice as sharp as the 40-150. Compared to the 40-150 at 150mm which is where I tend to shoot my 40-150, it is over twice as fast: F/1.8 compared to F/6.3. In late afternoon with a low sun partially shaded by trees and a bird in flight which is how my shot was taken, that extra lens speed and the ability to shoot at lower ISO while still maintaining a high shutter speed makes a noticeable and beneficial difference.

    Would I prefer a longer lens for this sort of shot? Yes, but I want it to be faster also. I'd really love an F/2.8 or F/4 300 mm. I spent a fair amount of time tossing up between the Oly 75-300, the Panny 100-300, and the 75 before going for the 75. I could either have length or speed and after considering where and when I shoot I went for speed. I don't regret that but I do agree that a longer lens would be better for this sort of work in a lot of ways. I had to make a choice between 2 less than ideal options, long focal length but slow lens speed or shorter focal length and fast lens speed. I went for lens speed and I haven't regretted it.

    Effectively I opted for getting the wide end of the 75-300 with a lot more lens speed and cropping when I couldn't get close enough.
     
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  10. uci2ci

    uci2ci Mu-43 All-Pro

    Jun 22, 2012
    Los Angeles, CA
    Sam
    Others have already hinted at this, but i'd like to highlight it. Beside absolute sharpness of the optics, there is also the issue of motion blur at longer focal lengths. I have the 100-300 panny and 14-150 Oly. I dont have the 75mm. One thing i can tell you is that i find it very hard to get a sharp 100% crop from the 100-300mm at full zoom, unless i have a high shutter speed like 640 and above. Even then there are frequent occasions where 1/640s wasnt enough to cancle my shaky hands. 100% crops from my 14-150mm are usually much crisper than the 100-300 even though speed wise they are the same and both are known to be less-than-stellar at full zoom. Dont get me wrong, i love the 100-300mm, but i usual have to set the ISO higher than i want and take a few shots to get a sharp picture worthy of cropping.

    The 75mm is SHARP, and being so fast, i doubt you will have any problems with motion blur. It might not be twice as sharp, but atleast you dont have to double check your shots in less than optimal lighting to see if you can even crop
     
  11. Rudy

    Rudy Mu-43 Veteran

    449
    Jan 24, 2013
    Oakland, CA
    I looked at the links and judging from their measurements the 75 is actually twice as sharp in many cases...
    I would love to see some real images of the 40-150 at 150 vs. the 75 cropped to 150 view to get a better feel for the trade-off if any.
    Rudy
     
  12. drcolby

    drcolby Mu-43 Regular

    30
    Jul 4, 2012
    Correct this please. If I take the 75mm 1.8 on my OMD and set the tele-converter to on (2x) what am I losing and is this now a 300mm?

    Thanks,
    Dave
     
  13. Rudy

    Rudy Mu-43 Veteran

    449
    Jan 24, 2013
    Oakland, CA
    The digital tele-converter just saves the center crop. There is no benefit over doing it in post processing except that your preview will be larger and it might be easier to see if your subject's eyes were open...
    In any case, your lens obviously stays a 75mm no matter what.
    My question was how a cropped version holds up against a zoomed image.
    Rudy