Where do people find lens performance details?

Discussion in 'Native Lenses' started by MidasKiss, Nov 30, 2015.

  1. MidasKiss

    MidasKiss Mu-43 Regular

    59
    Sep 15, 2015
    Sydney, Australia
    Hey everyone,

    I always see people saying that X lens peforms best at X aperture or Z focal length for zoom lenses. I was just wondering where people find this information? Is it mainly from personal experience and word of mouth? Also, is there a better word for this? Lens profile, etc?

    I've managed to find this review for the O12-40 f2.8, I'm not sure if it is reliable but that's the kind of information I'm looking for. I know there are more important things to worry about but I'm waiting on my camera and lenses to be delivered and I still haven't even been notified of shipment ;)
     
  2. mcasan

    mcasan Mu-43 All-Pro

    Feb 26, 2014
    Atlanta
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  3. piggsy

    piggsy Mu-43 All-Pro

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  4. mcasan

    mcasan Mu-43 All-Pro

    Feb 26, 2014
    Atlanta
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  5. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    It depends, it could be personal tests but most often are just lab test reviews. Some are from: lenstip, slrgear, dxomark, photozone, cameralabs, photographyblog, ephotozine, photoreview, digitalversus, luminous-landscape and a few others and personal blogs. Just type "lens name review" on google and browse through the first 50 results.

    Many sites uses different procedures for testing and different lens samples so results can differ. They are generally quite consistent but there can be significant exceptions. The best thing is to check out more then one. It's worth reading the whole review, especially the longer ones (lenstip, photozone).

    The different performance at various apertures can be seen at home with a few test shots, on a tripod or with fast shutter speed. For focal length comparison is a little more complex because you need to keep a similar framing moving around the camera but can be done nonetheless.

    I think reviews are generally correct, the hardest part is to understand what those numbers really means. Is 2750 so much better then 2460 to justify the extra $400? Am I going to see this in normal shooting conditions? Does this apply also for infinity focus? But this kind of problem is the same for any review and personal opinions.
     
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  6. MidasKiss

    MidasKiss Mu-43 Regular

    59
    Sep 15, 2015
    Sydney, Australia
  7. MidasKiss

    MidasKiss Mu-43 Regular

    59
    Sep 15, 2015
    Sydney, Australia
    I have heard that but I'm never sure which rules like that still apply to M43. Looking at the graph in the review I posted (copied below) it seems that the 12-40 pretty much consistently decreases in sharpness from f2.8 moving towards f22 and is generally sharpest from 12-25mm. Looking at the 60mm macro and 45mm f1.8 it seems that they peak around f2.8/4. I'll have to read some of these other reviews to see if they find the same results.

    If so I might just think f8 and be there!

    3988_roz_centr.
    [​IMG]


    Thanks for the replies. I do find it hard to understand the numbers, though the graphs make it easier. Whatever it is it's best at the high points right ;)

    For some reason dxomark will not run on my internet. If I go through a proxy it works, but it's a little bit annoying so I tend to not use it even though I see their metrics used all around the net. Now I'm off my mobile the lenstip site looks actually pretty good so I'm glad i found that one. Though it doesn't have everything, I'm hoping to find the 40-150 f.4-5.6. I'm off to the doctors for now, thanks for all the sites! Gives me some good night reads.
     
  8. What used to be f8.0 for the basic max sharpness in the 35mm film world is now f4.0-5.6 in our somewhat smaller digital format. Most of our native lenses here will peak out around those stops. Be careful of trying to compare results across different web sites...sometimes you'll wonder if they're even testing the right lens. Back in the day, I used to live for the newest Modern Photography lens tests...especially when they featured some Canon glass. Those pages got a lot of attention.
     
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  9. wjiang

    wjiang Mu-43 Hall of Famer

    I like to see a multi-dimensional map view like DXO or SLRGear have to get a sense of how a lens performs across aperture, zoom, and angle/distance from centre.
    Then there are other factors like C/A, fringing, coma, distortion, flare, vignetting, sharpness at infinity/MFD and especially bokeh quality that really need lots of sample shots to become clear.
     
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  10. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    As far as I know "f8 and be there", even if it is quite debated, means to remember that the most important thing is being there more then fancy settings (especially for reporters). f8 gives enough DoF to get the shot and a reasonable shutter speed.
     
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  11. mcasan

    mcasan Mu-43 All-Pro

    Feb 26, 2014
    Atlanta
    Nikon 50mm Lens Comparison

    20- Choosing The Best Aperture- f8 And Be There

    "While the photos were all sharp from f/2.8 all the way up to f/18, I found that the sharpest aperture seemed to be f/7.1. Very interesting." What is the Sharpest Aperture on a Lens?

    KNOWLEDGE:- What Is The Best Aperture To Use? [Article]

    It Must Be f/8 - Modern Lenses and Their Sharpest Apertures - TOTWPhotographing Spaces
     
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  12. T N Args

    T N Args Agent Photocateur

    Dec 3, 2013
    Adelaide, Australia
    call me Arg
    For m43 don't trust lenstip or photozone, as they test the lenses uncorrected, i.e. half-finished! This is a stupid idea, being purist to the point of dysfunction, as no-one will use the lenses that way on m43 cameras unless they are deliberately disconnecting them from the camera system electronically. You want to know how your lenses will never perform? Go to the above sites.

    So, look for a site that tests the lenses with inbuilt correction enabled. slrgear is an example.
     
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  13. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    I tend to buy the lens, use it for a few months and see if I'm happy with it. If I'm happy I keep it if I'm not I sell it and consider the loss (if any) as a rental fee. It turns out that it's very cost effective to buy lenses and resell them a few months later, I've actually sold several for more than I purchased them for.

    It also turns out that I'm generally pretty happy with most of the higher end equipment (for a given period), I think if the item was aimed at professionals it's generally going to be of a very good standard regardless of the brand.
     
  14. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    @mcasan@mcasan I'm not saying that f8 is not a good aperture for 35mm lenses, it is. I'm saying that the quote you used is not about sharpness.
    You can google for articles where the actual quote is discussed (attribution, origin, meaning) like his is one for example:

    What does "F8 and be there!" REALLY mean?

    BTW most fast primes peak well before f8, this is from one of your links: "Most lenses are their sharpest from two stops below maximum to about f/8."

    and if you consider the ISO performance of film in that period f8 is not exactly the best for shutter speed (hence sharpness). So it makes more sense IMO only when you think about DoF, zone focus, etc.
     
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  15. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
  16. T N Args

    T N Args Agent Photocateur

    Dec 3, 2013
    Adelaide, Australia
    call me Arg
    There is not much point in analysing m43 lenses' sharpness beyond about f/8 on the modern m43 sensors of at least 16MP. The physical phenomenon of diffraction takes over and limits the lens sharpness. That is why you see the sharpness result falling constantly after f/8, and it is not a deficiency in design, as there is nothing that can be done to make the lens better at f/22 for instance. (excluding post processing)

    But I agree with you that some modern high-grade m43 lenses are designed to be at or nearly at their maximum sharpness even wide open. This is a sensible approach by designers, given that there are only a few stops of aperture available before diffraction sets in, so they had better be good in that range!
     
  17. piggsy

    piggsy Mu-43 All-Pro

    I asked a bunch of basic questions about diffraction and lens testing a while ago -

    lens nerds: what's up with different lens behaviours with diffraction?

    which eventually led me to this excellent article on lensrentals

    LensRentals.com - Overcoming My f / Entekaphobia

    the gist of which is

    another good point made - that you can see on slrgears tests and others that have a detailed map of performance - is how narrow the peak centre performance can actually be and how different stops will prioritise different performance in different places. Peak sharpness over something like 3% of the image and worse sharpness everywhere else isn't a great reason to shoot things at f4-5.6.
     
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  18. T N Args

    T N Args Agent Photocateur

    Dec 3, 2013
    Adelaide, Australia
    call me Arg
    I agree that diffraction softening doesn't warrant f-stop-phobia. The aim of my post was to point out to the OP that the drop-off he noted in the graph he posted of the 1240PRO wasn't all about lens design.
     
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  19. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    My favorite thing about the "f8 and be there" quite is that it was coined in the days of large format 4x5 press cameras life the Speed Graphic.

    If one believed that it was actually technical advice rather that just "show up and pull the trigger" the modern analogue for m4/3 would be "f1.2 and be there!"
     
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