Macro, how to obtain greater depth of field?

Discussion in 'Nature' started by june_daley, Apr 10, 2009.

  1. Hi everyone,
    I own a Canon 60mm f.2.8 macro lens on a Canon 40D and am starting to delve into macro photography. With a 60mm, I do need to get very close to an object to fill the frame and am having difficulty with depth of field.
    I have read that to obtain a greater depth of field you need to think of your insect/flower as a 2D object and view it from above or an angle where most of the object is the same distance away from your lens, which I understand makes sense. However, is there another way? I want my background to be almost completely out of focus, but want an entire flower bud or butterfly to be in focus. I've tried stopping down my lens but then I have to increase my ISO to at least 1000 to still get a clear, sharp photo.
    How does everyone do it? I photograph moving objects like bees, so I still need a fast enough shutter speed to capture that. Any opinions/suggestions would be greatly appreciated as I am struggling a bit!
    Thanks :)
     
  2. One thing that can work is a tilt/shift lens such as the Nikon 85mm PCE. It doesn't actually have more DOF than any other lens (all lenses have the same amount of DOF,) but it repositions the focus plane.
    Kent in SD
     
  3. Stop down to f11 or greater, use flash to get more light there (off-camera is best), a tilt-shift lens (ala Canon TS-E 90/2.8) used with extension tubes and extenders and perhaps even a close-up diopter filter.
     
  4. The only way to increase the depth of field at a given magnification is to stop down. To do so, you must compromise shutter speed and perhaps the ISO setting, or add more light (e.g., use a strobe).
    You can make better use of what depth of field you have by making sure as much of the subject is parallel to the film plane as possible. If you are shooting a living thing, make sure the eyes are in focus - everything else is secondary. Insects slow down when cold. Early morning is a good time to catch them in a stupor. There are many helpful tips in "Closeups in Nature" by John Shaw.
     
  5. Thanks for all the advice, I hadn't thought of using flash (how silly am I). I will aim to get out earlier in the morning and catch those insects when they're sluggish!
    Thanks for the book advice too I will check it out. Cheers!
     
  6. Another technique would be multiple exposures with each focussing on different (planned) areas.
     
  7. aaah... that's a great idea Mary - thanks!
     
  8. stemked

    stemked Moderator

    Edward's suggestions are dead on. If you are going to use flash though it is going to be helpful to get the flash off the hotshoe; better yet two flashes (one TTL one fill-in) will really improve your shots. And to help with the hotspots you will get with the flash a polarizing filter should help some.
    Check out John Shaw's "Closeups (something)" book. It will give excellent suggestions.
     
  9. There is a technique that illuminates the subject with a thin horizontal lamina of light. The lens is mounted vertically and focussed at this distance. The subject is then raised/scanned through this light beam while the film is being exposed. This way the out-of-focus portions of the subject receive no exposure and the resulting photo has extreme depth of field. There is commercially available equipment for this method, but I remember a magazine article about 15 years ago that showed you how to make your own equipment at low cost.
     
  10. I second the tilt and shift if you can only take one shot.
    If you can take multiple shots, you can vary focus, and use software to layer the shots for extreme DOF. There is a 3rd party plugin if you have older photoshop, or I believe CS3 has this built in. IIRC the plugin was like $25, not too expensive.
    Tilt lens though is a great option for macro, landscapes, and obviously architecture. It is also useful as a panoramic lens.
     
  11. Just another book recommendation: I find this is the most comprehensive book on the subject.
    Oh, and BTW, at these magnifications, focal length doesn't influence DOF as one would normally think - magnification alone does that. But what one can do is use a longer focal length and stop it down to achieve the desired DOF, but frame it so as to include a background that is in the far distance and therefore very much out of focus. For speed, use flash, like many have already suggested - even if it takes some practice to make it look convincing.
     
  12. John .......that is working vary well. (Stacking images)
    You mentioned on your web page that you bump the focus from front to back. In the playing around with macro that I have done you set the magnification you want with the focusing ring, then adjust focus by moving forward or back to fine tune where you want the focus plane to be. To achieve the stacking shots you did, did you have to use a focusing rail that adjust the camera and lens distance to focus farther into the subject? It seems like adjusting focus would be hurt the ending result.
    I just got CS4 three days ago I am really happy with the speed and control of image adjustments in RAW, there is even a faster work flow in editing RAW images now then you can do in jpeg.
     
  13. You might think you could hurt the end result in several ways, but the software engineers seem to have foreseen and solved them. Check out my post: http://jwallphoto.blogspot.com/2009/01/stack-stitch-voodoo.html
    I think you could get an excellent result with the technique you describe, and in fact it's probably the best way -- and the only way to ensure you keep the same magnification ratio. However, it isn't necessary. You can get good results just by turning the focusing ring in very slight increments. I haven't done a stack in a while, but I recently downloaded an update to CS4 that supposedly corrects even the minor stacking artifacts that I've noticed in my shots. I'm hoping I can get out this weekend to check it out.
     
  14. It is already mentioned to get as parallel as possible to your subjects, this will enable you to use a smaller aperture number if you need it. But it must be in combination with having a good subject to background distance. If it is a butterfly in a cluttered bush, you are either going to get shallow DOF or a cluttered background. If it is a butterfly on a single flower, with the background a good distance away - you can crank up your aperture to f11/f16/f22, get the DOF you need, and still have the blurry background you want to achieve.
    All the other solutions above are fine and good, but this "in the field" approach has been working for nature photographers for decades. It is really going to be the background that makes or breaks these types of images.
    Mark
    blog: http://www.grafphoto.com/wordpress
    site: http://www.grafphoto.com
     
  15. By the way, the advent of focus-stacking doesn't change the importance of background, but it gives nature photographers a tool they didn't have a decade ago. The shot of the Indian Warrior wildflowers at the bottom of this blog post is an example. You couldn't have gotten the front and back flowers in focus while keeping a soft background without focus-stacking (at this distance; this is an uncropped image), which lets you use a large aperture such as f/4 for each stack: http://jwallphoto.blogspot.com/2009/02/lily-pond.html
     

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