Photo sharpness

Discussion in 'Beginner Questions' started by tiaan_seynberg, Mar 2, 2015.

  1. Good day all
    Here is a photo of a snake I post
    https://www.facebook.com/photo.php?fbid=10205612134841062&set=pcb.10153039391951043&type=1&permPage=1
    I cant seem to get the photos sharp
    I use my Sigma Mcaro 105mm lens, Iso 500, F16, S160, I shoot Raw and Jpeg.
    I tried my Nikon 70-300mm and 18-105mm
    I use flash and no flash.
    I even bumped my fstop up to 22.
    I know a tripod will work better, but is is hard when you lay on the ground close to venomous snakes to use one.
    I do not care if the whole body is not sharp, but at least the part that is of the ground.
    Will i do better with a fix 50mm lens maybe.
    Or does anyone have something else in mind I can try
    Regards
     
  2. Doesn't seem too "not sharp" to me. However, if it were me, the first thing I'd try to change is the shutter speed. 160 doesn't seem fast enough with a long lens (depending on how study you are). As a rule of thumb, I always try to shoot just above the longest focal length of the lens. For example, 250 for a 200mm.
     
  3. I did try that aswell, not with the photo I post, but it did not look any better
     
  4. There is a point where stopping down further will actually decrease resolution (diffraction), so what you gain in depth of field is lost again in overall sharpness. I'd stay away from f/22 for this reason actually.
    Have you tried an online depth of field calculator based on the subject distance you work with? At close distances, limited depth of field is simply a limitation that you cannot get around unless you resort to focus stacking, which is hard if animals move between shots.
     
  5. Although the small size of the images makes evaluating the sharpness difficult, I think the photos are sharp. Going to a 50mm won't do anything for you except get you a lot closer to the snake!!
     
  6. That's what I'd do, shoot with a 50mm and get closer. Take one for the team and get bit a few times. :)
     
  7. How are you managing focus?
    Manual? Through the lens autofocus (phase detection) or live view autofocus (contrast detection)?

    If phase detection AF: what settings? Single or continuous? Single or multi-sensor? Have done any autofocus micro
    adjustment settings for your lenses?

    With raw processing, what are your capture sharpening settings? Are you output sharpening (not r commended for
    Facebook or other social media sites as they do their own compression and sharpening?
     
  8. As others have said it's hard to say for sure with a small web image but they look sharp on the screen from this end. A couple maybe if you looked at them at 100 percent in Photoshop might be a touch soft but others look like they are tack sharp. Some are pretty good, in fact.

    Is your concern that the background is out of focus? It's supposed to be in this situation. You're shooting up close with long lenses so your depth of field (the range of area that is in focus) is shallow, but again that's a good thing. What you are getting is what photographers refer to as good "bokeh" that keeps the background from being distracted. If everything was in focus there would not be as much emphasis on the snake.
     
  9. James G. Dainis

    James G. Dainis Moderator

    I assume you want the entire snake from head to tail, not just the head, in focus. The problem is depth of field (DOF). I don't know how far you were from the snake. From the photo I would guess about 4 feet. With a Nikon D7000 at 4 feet, f/16, 105mm lens the acceptable depth of field would be

    Near limit = 3.87 feet

    Far limit = 4.13 feet

    or a distance of only 0.26 feet (about 3 inches) in which everything would be in acceptable, sharp focus.

    A shorter lens such as the 50 mm would get you a DOF of about 1.72 feet at a four foot distance but the snake would be half the size in the photo. You could crop out to get a more snake filling photo.

    You can see in the second photo in that series on Facebook that the snake's head is sharp as is the part of the body that is about the same distance from the camera as the head. A leaf and the dirt against that part of the body is also sharp.

    Here is a depth of field (DOF) calculator that you can play with:

    http://www.dofmaster.com/dofjs.html
     
  10. James G. Dainis

    James G. Dainis Moderator

    Oh, and you can see from that DOF calculator that if you use the 50mm lens at two feet to get a frame filling photo of the snake, you are back to a depth of field of only 0.26 feet or about 3 inches again. Better to shoot from a further (and safer) distance and crop out what you need.
     
  11. Increasing distance, i.e. reducing the size of the snake in the image, cropping to/enlarging the image again will get you in a safe spot, but not create greater DoF, except sometimes by virtue of the difference between unsharp and sharp becoming smaller due to reduced sharpness of the supposedly sharp parts.<br>Final magnification and f-stop are what counts.
     
  12. For this particular subject I'd use longer lens (more distance between me and the subject), like Sigma 150 or even Nikkor 200mm macro. It's good to have second set of eyes (+ deterrent) while you are concentrating on getting the image. A live bait would help too :>)....as a distraction.
    Les
     
  13. Thanks for the information,
    I use mainly manual focus
    I will play around with all the advise you all gave me, at least I here that my macro lens is not that bad as I thought. I did however got some good macro photos with the lens in the past.
    I must maybe try to do a snake shoot in the studio, since I know that photos is as sharp as it will be with the light.
    Regards
     
  14. the camera lens acts the same way the eye does the higher the f stop the greater the the sharpness on the depth of scale .the lower the f stop the the focal point wil be sharp and every thing else blurry before and after the focal point . You can't achieve these affects if you use the automatic settings on a digital camera. You will have to use the aperture priority settings so you can use a higher f stop which may make the camera need a slower shutter speed .Which may requier you to use a tripod ,so the camera doesn't move during the exposure.
     
  15. Not had to photograph a snake [ thank goodness :) ] but when shooting garden railway trains from their height I organised myself a short monopod for my SLR out of a bit of aluminium tube with a quarter Whitworth screw to attach to camera. This supported the camera at a comfortable height as I lay on the ground for the shots .... others I know use beanbags to rest the camera on.
     

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