1. Welcome to Mu-43.com—a friendly Micro 4/3 camera & photography discussion forum!

    If you are thinking of buying a camera or need help with your photos, you will find our forum members full of advice! Click here to join for free!

Is the DOF difference between M4/3 and full-frame really 2 stops?

Discussion in 'Back Room' started by hookgrip, Apr 19, 2014.

Thread Status:
Not open for further replies.
  1. FlyPenFly

    FlyPenFly Mu-43 Veteran

    448
    Feb 15, 2011
    IIRC, if you account for aspect ratio, it's somewhere around 1.83.

    You know what's more interesting though?

    Go through your Lightroom catalog and look at your images that you rated 4 or higher. For me, only 3-5% of my shots are shallow DoF that are what I consider "Keepers". Almost all of my shallow DoF shots are throw aways. Even with portraits. My entire catalog is about 80% APS-C and FF and 20% MFT.

    But when I think about it, my favorite classic photos of all time, they're almost all entirely not shallow DoF. For shots where I had DoF problems, I've never had a shot where I thought, man I wish I had a bit less DoF, it's always been I wish I had a bit more.
     
    • Like Like x 2
  2. zapatista

    zapatista Mu-43 Top Veteran Subscribing Member

    671
    Mar 19, 2012
    Albuquerque, NM
    Mike Barber
    So if I understand this correctly someone from the dpreview m43 forum invaded mu-43.com causing much consternation and useless discussion?
     
  3. hookgrip

    hookgrip Mu-43 Regular

    150
    May 21, 2013
    No, I saw the comparison shots on DPReview and was simply curious as to what the real DOF difference was between MFT and FF. I like to use shallow DOF with moderately wide to normal lenses for my style of shooting and am trying to get used to the reduced flexibility of MFT with regard to that point. (my other camera is a 5D). I was originally planning to get the PL25, but after I saw that it probably wouldn't give any more background blur than a FF lens at f/2.8 or f/3.2, I decided to pass. It seems that there is no other option than to lug my 5D and the Sigma 50mm f/1.4 around for those types of shots.

    No need to turn this into an argument. I'm not trying to put down MFT; after all, I currently own and use a MFT camera myself. If the discussion is useless to you, feel free to not post in the thread :smile:
     
  4. zapatista

    zapatista Mu-43 Top Veteran Subscribing Member

    671
    Mar 19, 2012
    Albuquerque, NM
    Mike Barber
    It seems like you have answered your own question.
     
  5. zlatko-photo

    zlatko-photo Mu-43 Veteran

    228
    Jan 8, 2014
    I agree, no need to turn this into an argument. It's a good question. And the answer is good and practical to know. The question would be equally valid if one were asking about DOF differences between M43 or FF and larger formats, such as 645, 6x7, 4x5 and 8x10. Photographers like to know these things.
     
  6. bikerhiker

    bikerhiker Mu-43 Hall of Famer

    Dec 24, 2013
    Canada
    David
    Photography is a 2 dimensional art, so therefore there is only ONE plane of true sharpness and that plane must be in parallel to the imaging plane of the camera. Everything else in front or behind this plane of sharpness is based on a perception of sharpness of your own eyes based on the diameter of circle of confusion. Since our eyes also has its own MTF (Modulation Transfer Function), what I see as being sharp will or may NOT be the same as what you see as being sharp. Therefore, measuring it in stops is NOT an accurate way to gauge how much. The measurement of DOF is based on subject distance and the diameter circle of confusion of the format used. With a full frame like a Canon 5D, it has a circle of confusion diameter of 0.030mm, whereas with a MFT like my E-P5 it has a circle of confusion diameter of 0.015m which is half of that on the full format.

    For example. If I aim to take a photo using a Canon 5D with a 50mm @ f/1.4 of a subject that is 2 meters away from the camera, I get a total depth of field of just 0.13m (that's 13cm) with a front DOF perceptible sharpness of only 6cm (0.06m) and the back DOF perceptible sharpness of 7cm (0.07mm) of that subject matter. That's pretty thin. So if you want to get such thin DOF like that in full frame with a MFT,

    Then you will have to shoot @ 50mm f/2.8! Which is WHY and the main sole reason I own a Lumix 35-100 f/2.8 pro lens! With the Lumix lens set to 50mm @f/2.8, I get exactly the SAME DOF (0.13m) of the same subject matter and same or very similar isolation feel of a 50mm @ f/1.4 on the 5D. The only change I need to do is to change my shooting style because I will be shooting 100mm equivalent of 35mm FF with my Olympus E-P5. So no more waist up portrait if I strive to get the same isolation feeling as a 50mm @ f/1.4.

    In terms of DOF, a Canon 5D with a 50mm @ f/2.8 is going to give you the same DOF coverage as my E-P5 with a 25mm @ f/1.4. This is simple math. But the look and feel of the isolation will not approach the same level, because you are dealing with 2 different focal length lenses (a 50mm and a 25mm) and therefore the isolation feel will be slightly different.

    If I strive for the BOKELICIOUS effect similar to a full frame experience, I use my Lumix 35-100 f/2.8 and find the same working DOF coverage distances of my favourite 35mm lenses (I shoot Nikon FF with D4, Df and D800) and adjust my shooting style to account of the 2x crop factor. So if I want similar isolation feel of my Nikkor 85mm f/1.4G lens @ f/1.4, then I would set my Lumix @ 85mm @ f/2.8 and adjust my framing and style accordingly while maintaining same distance. Therefore, the limitation of the MFT is the cropping factor.

    Hope this helps.
     
  7. EarthQuake

    EarthQuake Mu-43 Top Veteran

    934
    Sep 30, 2013
    I think this is an odd way of explaining the concept, and I have to strongly disagree with some of what you're suggesting. A 50mm lens on FF and on M43rds will give you completely different angle of view, you have to move your position relative to the camera, which means completely different perspective distortion/compression. This also means apparent background blur is totally different, so in real use, a photo taken with a 50mm 1.4 on FF, and 50mm 2.8 on M43rds look extremely different, even if a DOF calculator tells you each has the same amount in focus.

    ie: http://howmuchblur.com/#compare-1x-50mm-f1.4-and-2x-50mm-f2.8-on-a-0.9m-wide-subject
    or: http://howmuchblur.com/#compare-1x-85mm-f1.4-and-2x-85mm-f2.8-on-a-0.9m-wide-subject

    The same focal length lens and an aperture stopped down two stops on Mf43 certainly will not give anywhere near the "bokelicious" look of the FF combination, to get close, you have to use a M43 lens with half the focal length, that is faster than the FF combination. For instance, the Nocticron gives you a look very, very similar to an 85/2.4.
     
  8. Bhupinder2002

    Bhupinder2002 Mu-43 Hall of Famer Subscribing Member

    I agree
     
  9. Bhupinder2002

    Bhupinder2002 Mu-43 Hall of Famer Subscribing Member



    ???:horse::horse::horse::horse::dash2::dash2::dash2:
     
  10. Bhupinder2002

    Bhupinder2002 Mu-43 Hall of Famer Subscribing Member

  11. shutterduster

    shutterduster Mu-43 Regular

    144
    Feb 8, 2013
    Keremeos, BC. Canada
    Dave T
    Same old Blah Blah Blah. Take your camera out and shoot. Too much time reading DPR will cause you to stop shooting.

    With all due respect and all that bother, Dave T:wink:
     
  12. bikerhiker

    bikerhiker Mu-43 Hall of Famer

    Dec 24, 2013
    Canada
    David
    Again, you are comparing 2 different lenses. A 25mm lens does not behave exactly the same as a 50mm lens. Basically, you are cropping a 25mm lens to behave like a 50mm lens, but that lens is still a 25mm lens. The same with the Nocticron. It's a 42.5mm lens compared to an 85mm lens. Yes, it does provide a similar look, but that is all it does. Provide a similar look. If you want the exact same look, then you need to use the same lens of the same focal length. If you want the same look of a 50mm, then you need to use the 50mm. The only downside to this same look is that, the crop provides a challenge for framing, because it's a 2x crop. But it's not undoable.

    For general application, my Panasonic 25mm shot at f/1.4 provides a very similar look like my Nikkor 50mm f/1.4G @ f/2.8 when printing. It's when people dissect photographs like Dr. Quincy is when we have this stuff going on. When you print, you'll be hard pressed to tell the difference!
     
  13. Art

    Art Mu-43 All-Pro

    Mar 13, 2011
    San Francisco, CA
    It takes time to appreciate deeper DoF and practice how to compose to incorporate the background. Content is king, always! IMO, shallow DoF is inappropriate in most travel/family photography and is rather a drawback of larger formats where the only way to keep ISO low is to open up aperture.

    I appreciate PL25 for half/full body portraits because at f1.4 it keeps the background clear enough to have context and yet just enough isolation for 3d effect which uniquely brings images to life.

    Shallow DoF is a highly specialized type of photography belonging to fashion industry. m43 is a unique format which allows both sufficient control over DoF with certain lenses and shooting wide open in low light with sufficient DoF in most cases.

    By the way, most people turn to DSLRs to get more detailed images, fast AF and good low light performance. Most definitely not shallow DoF.
     
    • Like Like x 2
  14. Bhupinder2002

    Bhupinder2002 Mu-43 Hall of Famer Subscribing Member

    :2thumbs::2thumbs:. I feel sick when I all these comparasion which have no meaning real life for real photographers :biggrin:
     
  15. EarthQuake

    EarthQuake Mu-43 Top Veteran

    934
    Sep 30, 2013
    A focal length does not have a "look". The physical focal length, combined with the size of the sensor is what determines angle of view, which in turn determines working distance for a particular subject (ie: a head shot, or a full body shot), and thus perspective (perspective is solely a product of distance to subject and has nothing to do with focal length). A 50mm lens cropped to a head shot on FF doesn't look anything like a 50mm lens for a head shot on M43, as the working distance and perspective are completely different. I don't see any point comparing a specific focal length over different formats, as the photos will be drastically different (different framing if taken from same distance, different perspective if camera is moved to equalize framing).

    Ignoring DOF, to get the same framing, same angle of view, to take the essentially same photo, you need a focal length of half on M43 (-/+ a bit for the different aspect ratios).

    Now, DOF is the only real area where different focal length lenses (or rather, actual focal length on FF side and equivalent FL on M43 side) vary in any way, expect of course for the typical differences in rendering that every lens has. Of course I agree with your second paragraph, as I have verified the behavior myself on both formats. The examples posted in this thread are faulty due to the differences in distance to subject/framing altering the DOF/background blur, which I assume are due to quickly taking handheld shots instead of using a tripod to maintain the framing.
     
  16. Lisandra

    Lisandra Mu-43 Veteran

    234
    Nov 16, 2010
    theres also lens focal length to consider here, and people are gonna argue this with me to death, but a 200mm lens on ff even stopped down to f5.6 looks very different than m43s at 100mm f2.8.
    But at any rate its doubtful anyone can tell whats what. Ive proven it. Show two different photos to anyone photo savvy and its almost near impossible for them to tell what was shot with what, even if i tell them what was used in both cases to begin with
     
  17. Lisandra

    Lisandra Mu-43 Veteran

    234
    Nov 16, 2010
    so i guess i disagree with earthquake, i think focal lengths do have a look. Theres no way, no matter where you move or "zoom out with your feet" (gosh i hate that expression) that you can make a 50mm look like a 200mm, on any sensor.
     
  18. EarthQuake

    EarthQuake Mu-43 Top Veteran

    934
    Sep 30, 2013
    http://photography-on-the.net/forum/showthread.php?t=672913 - Very good explanation of how distance to subject determines perspective, 100mm, 200mm, these numbers have no relevance without a sensor to attach them to. On 645, a 50mm is a wide angle, on FF its a normal, on M43 its a portrait lens. Do these lenses transform when attached to different cameras? No, because there is nothing magical about a focal length.

    Its actually very easy to get the same look of a 200mm lens on FF with a 100mm lens on M43, I've done this myself, I suggest anyone else actually try it out, with a fixed subject, on a tripod, if you still have doubts.

    EM5, 100mm lens
    em5100mm.jpg
    Subscribe to see EXIF info for this image (if available)


    A900, 200mm lens
    a900200mm.jpg
    Subscribe to see EXIF info for this image (if available)


    EM5 25mm lens
    em525mm.jpg
    Subscribe to see EXIF info for this image (if available)


    A900 50mm lens
    a90050mm.jpg
    Subscribe to see EXIF info for this image (if available)


    Above shots: Apertures have been equalized to provide similar DOF (FF lenses are stopped down two stops extra). Minor differences due to different aspect ratio can be seen as well.

    Its also easy to make a 50mm lens "look" like a 200mm lens, at least in terms of the perspective compression that is usually associated with a 200mm tele, only caveat is that by cropping significantly you lose quite a bit of resolution. Just check the POTN link above for that comparison. Again, this is because perspective is determined by distance to subject, and has nothing at all to do with focal length. If this was not true, the very short focal length lenses in point and shoots and cell phones would be incapable of taking anything but photos with fish-eye-esq perspective distortion.
     
    • Like Like x 1
  19. pellicle

    pellicle Mu-43 Hall of Famer Subscribing Member

    Feb 10, 2010
    Killarney, OzTrailEYa
    pellicle
    its an approximation. There are variances depending on things like lens focal lengths and shooting distance compared. But x2 is a nice easy figure isn't it?

    in this post I compared 100mm full frame and 50mm 4/3

    http://cjeastwd.blogspot.com/2010/03/43rds-dof.html

    In that post I mention also that DoF is related to aperture diameter moreso than F-Stop

    HTH
     
    • Like Like x 1
  20. gcogger

    gcogger Mu-43 Veteran Subscribing Member

    409
    May 25, 2010
    UK
    Graeme
    The 'look' of a photo is determined by angle of view, perspective, depth of field and background blur; none of which are a characteristic of the focal length alone. I'm sorry, but there's no inherent 'look' to a focal length on different sensor formats.
     
    • Like Like x 1
Thread Status:
Not open for further replies.
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.