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F stops and depth of field

Discussion in 'Native Lenses' started by Ig7, Apr 27, 2012.

  1. Ig7

    Ig7 Mu-43 Veteran

    298
    Aug 24, 2011
    Travelling with my new e-m5 and Oly 9-18 and Pany 14-140 and need advice on what is thw best f stop to use for general lanscape shots. Using the apperture mode and really confused with the depth of field issue. Are 8 or 11 f stops best to get sharp lanscape shots?
     
  2. RussellOlaguer

    RussellOlaguer Mu-43 Veteran

    303
    Feb 12, 2012
    Paranaque, Philippines
    Russell Olaguer
    I've read that for M43, the most effective aperture to be used is f4~f5.6 if you want total sharpness.
    The diffraction on smaller aperture (f8 above) will cause the image to become less sharper.

    Please correct me if I am wrong.
     
    • Like Like x 1
  3. mister_roboto

    mister_roboto Mu-43 Top Veteran

    637
    Jun 14, 2011
    Seattle, WA, USA
    Dennis
    From what I understand, yes. That on most lenses, diffraction sets in around f8-f11. Most of the ยต4/3 lenses I have are tack sharp at f4-f6.
     
  4. When shooting landscape images at wider angles the DOF on a Micro 4/3 sensor is enormous, so it makes sense to shoot either lens at or near their optimal aperture for across-the-frame sharpness rather than to stop the aperture down excessively. For best results with the 9-18mm and the 14-140mm I'd be shooting between f/5.6 and f/8 which should be right in the zone of optimum sharpness and large depth-of-field.
     
  5. Ig7

    Ig7 Mu-43 Veteran

    298
    Aug 24, 2011
    Thank you. I always thought that I need to go to f16 or more to get the larger DOF.
     
  6. Dave in Wales

    Dave in Wales Mu-43 All-Pro

    Nov 5, 2011
    West Wales
    Ever thought of using the 'Scene' mode, nice quick way with no worries.

    Let the camera take the strain while you/yours enjoy the holiday.
     
  7. Ig7

    Ig7 Mu-43 Veteran

    298
    Aug 24, 2011
    I have thought of it, guilty. But then I feel that I am wasting the capabilities of this beautiful camera and the lens by doing so.
     
  8. RussellOlaguer

    RussellOlaguer Mu-43 Veteran

    303
    Feb 12, 2012
    Paranaque, Philippines
    Russell Olaguer
    Sorry for the dumb question...
    I'm not using any SCENEmode in my past DSLR cameras as well as to my m43.

    If I shoot RAW only, will it be affected by SCENE modes and ART FILTER modes?

    Thanks.
     
  9. Promit

    Promit Mu-43 All-Pro

    Jun 6, 2011
    Baltimore, MD
    Promit Roy
    You most likely do not want to go past f8 for maximum sharpness.
     
  10. songs2001

    songs2001 Mu-43 Top Veteran

    693
    Jul 8, 2011
    It depends what you mean by affected.

    Scene modes will change aperture and shutter speed, ISO. You can't change these in raw. If you are talking about sharpening, saturation etc...then your raw files are unaffected by them.
     
  11. songs2001

    songs2001 Mu-43 Top Veteran

    693
    Jul 8, 2011
    Even if you have diffraction, your overall image will be sharper if you stop down.

    Sometimes in landscapes you don't want the whole image to have overall sharpness.

    Only if you are printing large will diffraction be apparent.

    Your camera should have a DOF preview, you can use that and see if overall sharpness is adequate, if not stop down.
     
  12. On a larger format such as film or full-frame digital this would be reasonable, but not on Micro 4/3. The theory behind it starts to get a bit technical (circles of confusion and such like).

    Lots of heavy reading here.
     
  13. Kiwi Paul

    Kiwi Paul Mu-43 Top Veteran

    729
    Aug 15, 2011
    Aberdeen Scotland
    Just experiment, find a scene you like and take several shots from wide open to f11 and compare them, it's the best way to learn and understand the effects of different aperture values.
    However it's unlikely you will ever need to go above f8 to achieve adequate dof using a m4/3 system, generally anything around f5.6 - f7.1 gives more than enough dof.
    The pic below was taken with the 9-18 @18mm f6.3 and is sharp right through.

    Paul

    P1020250.
     
  14. flash

    flash Mu-43 Hall of Famer

    Apr 29, 2010
    1 hour from Sydney Australia.
    Gordon
    May I suggest you download one of the many depth of field calculators for your smart phone or use one of the Internet ones. Generally you just plug in your camera, focal length, aperture and focus distance and the program will show you your DOF at an average print size.

    Some of these calculators will also give you the "hyper focal" distance for a lens/aperture combination. This is the distance you need to focus at at an aperture to get the infinity point in the DOF. You'll quickly be able to remember a couple of settings you can take into the field. I'm guessing that at around f8 with a 14-40mm setting, focused at about 10 meters will be a good starting point.

    Gordon
     
  15. songs2001

    songs2001 Mu-43 Top Veteran

    693
    Jul 8, 2011
    M43 cameras don't have distance scales unless you are using the 12 2.0 or mounting third party lenses.

    Also these tables are acceptable sharpness, rather than optimal sharpness.

    40mm at f8, if you focus at the hyper focal distance of 44 ft you will only be in focus from 22ft to infinity.

    Good for taking pictures of stuff far away, but not so much if you want something close in focus as well.
     
  16. Ig7

    Ig7 Mu-43 Veteran

    298
    Aug 24, 2011
    Thank you everyone. I will set the camera to shoot raw+jpeg to be on the safe side ):
     
  17. oldracer

    oldracer Mu-43 All-Pro

    Oct 1, 2010
    USA
    I'm afraid this thread may have confused you more. There are two completely different concepts being discussed here, but in some cases interchangeably.

    1) The sharpest lens aperture. This is the aperture that produces the sharpest image of an in-focus subject, often found by using a lens test chart. For example: ISO 12233 Test Chart

    As people have said, this is usually at a medium aperture like f5.6 or f8. Wider apertures typically produce slightly less sharp photos due to shortcomings of the lens. Smaller apertures begin to degrade due to diffraction effects (basically, light waves getting too crowded going through a small hole).

    2) Depth of field. This (DOF) refers to the distance range of things that are in acceptable focus. The smaller the aperture, the greater the depth of field. You can easily see this for yourself. Focus on a near object and set your aperture to its maximum opening. Take the photo. Now do the same with the aperture at a much smaller opening. Take the photo. Now look at objects in the background and note that those in the first photo will be less sharply focused than those in the second.

    That's really all there is to it. IMHO if using the sharpest aperture suits your shot, that's fine. But using an adequately short or long shutter speed to stop or emphasize motion or selecting an aperture that gives you the DOF you need for the image are far more important. Who cares whether the image is at its absolute, theoretical best sharpness if it is not the image you want? But, on the other hand, if the image you want is that of a resolution test chart, go for the perfect aperture!
     
    • Like Like x 2
  18. songs2001

    songs2001 Mu-43 Top Veteran

    693
    Jul 8, 2011
    Raw and jpeg won't help with what you are asking.
     
  19. flash

    flash Mu-43 Hall of Famer

    Apr 29, 2010
    1 hour from Sydney Australia.
    Gordon
    At least it's a starting point. Better than the rubbish sprouted forth so far. The OP wants sharp images from fron to back. What better way than looking up and learning the hyper focal distance of his lenses. So far it all been about where the lens performs best. That won't help if what he wants is out of focus. So the lens is best at f8 (it may not be). If you focus on something 100 meters away then you'll still have an out of focus foreground. I suppose you could relish the fact that you out of focus foreground has no diffraction.

    The only point of optimal sharpness with a lens that doesn't tilt is the plane of focus. Everything else in fron or behind that is based on "acceptable" sharpness or DOF. If you want the largest zone of acceptable sharpness in a shot use the hyper focal distance of the lens. If you want critical sharpness throughout an entire image (except for where the subject is perpendicular to the lens) then you'll need a lens or camera with movements. The rest of us put up with acceptable sharpness.

    Regardless of whether a lens has a focusing scale or not, pointing a camera to a spot about 10 meters away and pre focusing just isn't that hard. And in the field, in the heat of battle, it's a good starting point. Not end point. Starting point. Although I suppose a wild guess and a prayer would do just fine as well.

    Gordon.
     
    • Like Like x 1
  20. songs2001

    songs2001 Mu-43 Top Veteran

    693
    Jul 8, 2011
    I don't disagree, about learning hyper focal points of your lenses. But no one hyper focal lenses that are 80mm equiv.