Canon FD 50mm f1.4 depth of field too shallow?

Discussion in 'Adapted Lenses' started by walter_j, Jun 28, 2015.

  1. walter_j

    walter_j Mu-43 Veteran

    364
    Sep 10, 2013
    Hagwilget, B.C., Canada
    Walter
    I took a few shots at a nearby mountain, but the moon was out of focus, and then focused on the moon, but the mountains were very soft even at small aperture of F22. Is this a normal issue, or perhaps an adapter problem? I have the Kipon FD adapter. I remember putting the lens aside after noticing this issue in the past, but now am trying to determine the reason for this issue. A roche (1 of 1)-16. ny ideas?
     
  2. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    f22 its probably that you're seeing diffraction ... it looks like either diffraction of fog on the lens to me.

    Are you focusing using the EVF and magnification to confirm focus?

    Considering that the shot is at infinity the DoF is meaningless at that sort of distance. 10km away, 100,000Km away .. all are "infinity"

    try f5.6 and focus carefully using the magnification

    PS: my copy is clear as a bell (to look at and with respect to focus)
     
  3. tkbslc

    tkbslc Mu-43 Hall of Famer

    If you suspect optical or focus issues, try shooting some easy subjects in the daytime at f5.6. If you can't get sharp shots there, then it's probably the lens.

    f22 will be soft due to diffraction, but I don't know about THIS soft. I don't see the EXIF, but was your shutter speed OK? Did you set the focal length for IBIS? Did you have any other shots that looked good?
     
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  4. edmsnap

    edmsnap Mu-43 Veteran

    430
    Dec 20, 2011
    Edmonton, Alberta
    How are you focusing? Once adapted, putting an FD lens to infinity using its focus ring will always be wrong as the adapters are made to allow for variances and they all focus past infinity. You need to set the aperture at 1.4, focus using the EVF and magnification, then keep the camera stationary (ie: tripod) while stopping down to 5.6 - 8ish. As noted above, if you stop down beyond that, diffraction will eat you like any other lens on ยต4/3. If you're still getting those results, then fog/haze could be the issue. Also worth checking that the lens is mounted correctly and functional - when you turn the aperture ring, is the aperture actually changing? To me, it kind of looks like the aperture might be frozen wide open (judging by the focus issues, the "glow," and the CA).

    A working FD 50/1.4 will give vastly better results than this.
     
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  5. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    to the OP

    this point:
    is significant ... it depends on the adapter, if you know your adapter well and good, but if you are new to FD it could be there is a problem in attachment. Some have a rotating engagement ring others just need to be mounted "right"



    the other type of adapter has the ring that moves this engagement pin:
    RJcouplingPin.

    and the way it engages

    RJcoupling.

    for more details look at my blog post here:
    http://cjeastwd.blogspot.com/2009/06/rj-camera-fd-adaptor.html
     
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  6. walter_j

    walter_j Mu-43 Veteran

    364
    Sep 10, 2013
    Hagwilget, B.C., Canada
    Walter
    I confirmed the aperture is moving prior to mounting, and checked that the shutter speed decreases when closing the aperture. At f5.6, I focused on moon using magnification (10x), and found the mountains were unacceptable. I'll try again tomorrow. The mosquitos are too hungry now.
     
  7. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    Hi

    actually you need to confirm that the aperture is moving AFTER mounting. Actually with that lens just looking at the front makes it really obvious. But as you say:
    it sounds encouraging that its all correct.

    I'd focus on the mountains first stopping down to f2.8 then if you wish to stop down further do it then. We just had a thread where the concept of focus shift was identified with lenses of larger than f2 when stopping down after focus. That may also be an issue. (see my discovery of the solution here and perhaps read some of the thread too)

    meantime (while out of the mossies) have a gander at this calculator:

    http://www.tawbaware.com/maxlyons/calc.htm

    plug in your numbers and put a distance like 1000meters into it ... the graph is just a flat sausage along the bottom because essentially (as the right hand col reports) that with the lens (theoretically) focused on 1Km away, that near focus was 62 meters away and far focus was infinity (like stars).

    I'll be keen to hear how it goes tomorrow :)
     
  8. Ulfric M Douglas

    Ulfric M Douglas Mu-43 Hall of Famer

    Mar 6, 2010
    Northumberland
    I'm not trying to be funny, but perhaps using such a specialised lens for something at the opposite extreme of what it was designed for isn't going to reward you with great sharpness. I always thought large-aperture 50mm lenses were for more in the portrait department.
    Do you own a m4/3rds kit zoom? : some of them are excellent for this job at f8
     
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  9. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    As tkbscl said: did you set the correct focal length for IBIS? Could be that over-correcting vibrations. Otherwise what was the shutter speed?

    Is this a crop or the full size image?

    The halo around the moon could be just that, an halo around a light source, especially at 1.4. The trees and the mountain looks micro blurred: motion, wrong ibis config or shutter shock (try anti-shock or a fast shutter speed).
     
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  10. walter_j

    walter_j Mu-43 Veteran

    364
    Sep 10, 2013
    Hagwilget, B.C., Canada
    Walter
    I don't own a single zoom. I'm considering the 12-40 though. I used a 2 sec delay to eliminate shutter shock, but I never tried turning off IBIS or setting it for the correct FL. It's mounted on a heavy tripod, from which I can get very sharp images from other lenses. Perhaps this lens is just not suited for landscapes. I will keep trying to sort this out. As for the moon - it is a bit overexposed and the halo makes sense.

    I focused after setting aperture, and find that this lens is very sensitive, where focus is at my limit of being able to turn the focus ring finely enough. That alone should indicate the lens is unsuited for this type of photography - for me anyways.

    I tried the DOF calculator, (entering 100mm including crop factor), and at 5.6 I get 302' near focus, and infinity at 3 miles.
     
    Last edited: Jun 29, 2015
  11. Ulfric M Douglas

    Ulfric M Douglas Mu-43 Hall of Famer

    Mar 6, 2010
    Northumberland
    It is also worth noting that a 2-second delay on tripod is set to eliminate movement from you pressing the shutter which is not the same as ShutterShock which is something akin to mirror slap in a DSLR and may or may not ever appear in your camera.

    On tripod set IBIS to OFF then you don't need to enter any focal length.
     
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  12. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    I'm far from an expert, but my first thought was that the depth of the adapter may be slightly off, preventing you from focusing at infinity. If you have another adapter or an another FD lens you could swap them out and see if the story is the same.

    Also, as far as aperture goes, I try to never go over f/8 with :mu43: due to the diffraction limit due to the pixel pitch of the sensor. With the 16MP sensors, you're going to start being impacted by this at anything over f/7. Given the crop sensor, I've found that the DOF at f/8 is almost always sufficient for my needs.

    Also, lot's of good advice here on either setting the focal length for the IBIS or turning IBIS off if you're shooting from a tripod (assuming you're using an Olympus).
     
  13. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    Hi

    Crop factors are not part of that calculator as it works on the principle of Circle of Confusion. So just leave it at 50mm and set a small circle of confusion. No point in going past the pixel pitch in size however as that's the resolution limit.

    Note their instructions
    Sometimes thinking in crop factors gets you down a blind alley :) note I used 0.019

    For instance

    19278069035_8a5c158480_o.

    Even set back at 100meters you can see the back DoF is rising to flatten out with a blur under 0.02 well into the distance, indeed to practical infinity. Set to 1000 meters (or a kilometer) its what I reported earlier.

    PS a really worthwhile tutorial

    http://www.cambridgeincolour.com/tutorials/depth-of-field.htm
     
    Last edited: Jun 29, 2015
  14. walter_j

    walter_j Mu-43 Veteran

    364
    Sep 10, 2013
    Hagwilget, B.C., Canada
    Walter
    I turned off IBIS with no improvement, so I tried my yashica 50mm, and the yashica is so much better. The canon 50 is just not very good. here's the yashica shot out of the camera. no ibis roche (1 of 1)-17.
     
  15. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    interesting, what was the fstop on the yashica?

    Have you looked through the FD lens to see if its foggy inside? The best way is to look in a dimly lit room with the only light on the other side of the lens from you. Orient yourself so that with (say) the light underneath (like a plain bulb) loo through from the top but have the bulb just out of view to one side. That really lets you see flare caused by fogging.

    Compare the two lenses. Your FD 50 may need a clean or be buggered.
     
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  16. walter_j

    walter_j Mu-43 Veteran

    364
    Sep 10, 2013
    Hagwilget, B.C., Canada
    Walter
    The yashica was also at f5.6. It seems free of fog, but when looking through the viewfinder with magnification - it just doesn't seem very sharp. The yashica f2 was obviously sharper through the viewfinder. What a shame.

    On a related note, I like the FOV of the 50, and am tempted by the Nokton 42.5, or perhaps the Nokton 58mm thats for sale here. I notice that the 42.5 rarely is sold here - maybe an indication that people just want to hang on to it
     
  17. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    yeah, its sad ... I bought my 50f1.4 to see if it would serve to replace my 100mm f2.8 on fullframe

    http://cjeastwd.blogspot.com/2011/10/portrait-lenses-5d-vs-gh1.html

    mine is quite sharp and once stopped down to f2 its equally as sharp and contrasty as my OM50f1.8

    Its not as contrasty at f1.4 but then in your example your first image was 5.6 right?

    Mines way better than that ... I assume (I'm not sure if you confirmed it) that you focused the 50f1.4 at about f2 before stopping down to 5.6 for taking the shot. As mentioned that can cause issues.

    Also I've had problems with fog on lenses outdoor (camping) when the temp warms up in the morning (and my lens is still cold from the night).
     
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  18. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    How do the lenses compare with a closer subject? If you can get sharp results from the Canon at closer distances, that could point to an issue with the depth of you adapter.
    The light volume of Nokton 42.5mm resales probably is simply a reflection that not too many folks are using that lens.
     
  19. Bif

    Bif Mu-43 Veteran

    380
    May 28, 2012
    San Angelo TX
    Bruce Foreman
    The 50mm f2 lenses are generally noticeably sharper than the 50mm f1.4 versions. Both (in their day) were intended as a "general purpose" do a bit of everything lens. The cameras we purchased in the late 1950's, 1960's, and 1970's generally came with this "shifty fifty" and often it was an f1.4. The f1.4's had larger lens elements and were more susceptible to flare and a bit of softness wide open.

    Quality varied considerably so you may have a softer Canon. I went through 3 Nikon 28mm f3.5's before I got a sharp one. A local Chinese photographer on Taiwan took me to a Nikon specialist in Taipei who had the instrument to measure lens centration error. The first one was 11% error, the second 7%, and when the third lens tested at 4% he pronounced it as about as good as it gets.

    I kept that one.

    Use your Yashica 50mm. You seem to have a good copy.
     
  20. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    But the 50mm/f1.4s were almost all better at f2 than the 50/f1.8s or f2s. That additional flexibility was quite expensive at the time, but the difference today is maybe $40-50, so the larger aperture seems worthwhile to me.
     
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