Mrs. Bluebird, depth of field and focus

Yesterday I was telling you a little about how I have my yard setup for photographing birds.  I mentioned that I have my blind setup right at the minimum focusing distance for my lens.  The lens I use most often for these types of shots is the Tamron 150-600mm.  When using the lens at 600mm at the minimum focusing distance the depth of field (DOF) is pretty small.

ISO 640, 600mm, F/6.3 @ 1/500th second

Hover over the image to view the camera settings used.  Click the image to view it larger.

If you look at the above image, you can see how shallow the depth of field is.  You can see the eye is tack sharp, but 3 or 4 inches away the bird's tail is out of focus.  It is important to remember this when using a telephoto lens at the longer end  close to your subject.  Since the DOF is so shallow your focus is critical.  If I had missed the eye by even a tiny bit, it would have been soft.  Images of wildlife or birds rely on the eye being in sharp focus!

When I hear people complain about getting soft images out of any telephoto lens, it is usually related to distance.  Either they are so close that the DOF is so shallow that they simply miss the focus point, or they are too far away and end up cropping the image heavily and expect the image to be sharp.  Keep this in mind when using those longer lenses.

This image was made using my Sony A77 II and Tamron 150-600mm Lens.  Both mounted on my Sirui Tripo and PH-20 Gimbal Head.

Macro Depth of Field

While I was in the smokies a few weeks back I took the opportunity to take a few photos for educational purposes.  

When people start photography, it seems Depth of Field is a concept that many struggle with.  Then, once they have it figured out, they get a macro lens and that frustration comes back to the forefront again.

Depth of field is, of course, determined by your F stop, but another factor that is in the equation is the distance from your subject.  This becomes extremely evident in macro work because you are only inches away from your subject.  The other problem that comes in with macro work is that true macro lenses are of longer focal lengths.  Our focal length is another factor that helps determine DOF.

Let's take this photo for instance.  This is a shot of some cone flowers.  I used an F stop of F/11, which when shot with a lens that is equivalent to a 35mm is more than plenty to give us a nice depth of field throughout the image.    My favorite macro lens is the Tamron 90mm.  So, again, we are very close to our subject and we are shooting at a longer focal length. 

Notice those red out of focus dots in the center of the image?  Those are aphids.  They are probably less than 2 inches away from the cone flowers.  You can see here F/11 was no where close to giving us enough DOF if we want both the flowers and aphids in focus.

Here's another shot of the aphids in focus.  See how quickly we lose the flowers?  Same F stop here, F/11.  

The only thing that changed here was my focus point.  You can see F/11 is almost nothing in macro work.  In the macro world, if you want a wide DOF you are going to find yourself shooting in the F/32 club a lot.

Hopefully this illustration helps you understand DOF when working with macro.  

BTW...there is dirt on my sensor here...Don't judge ;)

Don't overlook the details

During my Smokies Workshop a few weeks ago, while we were waiting on sunrise, or driving around looking for wildlife, I noticed several things that would make fantastic macro images.

I wanted to share a few of the images with you and remind you not to miss the forest for the trees, as they say.  Even though I was there to shoot grand landscape style images, I was on the lookout for these little details.  

When I saw that the morning dew had covered everything in sight, then I had to get the macro lens out and take a stab at a few shots.

First it was an attempt at spiderwebs.

This was shot at a very shallow depth of field for a few reasons.  First, I wanted to blur the background to a nice blurred non-distracting background.  Second, I wanted to get those cool out of focus dew drops on the other things in the background.  Lastly, I only wanted to isolate a few of the dew drops to be tack sharp.

This was shot using my Canon 5D Mk II and Tamron SP 90mm F/2.8 Di 1:1 Macro Lens.  I stopped the lens down to F/4 to get that nice, shallow depth of field.  I shot this in Aperture Priority, so with an ISO of 100, the shutter speed was 1/160th.

Next was the dew covered dandelions.

I did something with this pic that I very seldom do...I cropped it.  I have a good reason, though.  The composition I wanted was so close that it was inside the minimum focusing distance of my lens and I didn't have my extension tubes.  So, I shot the image getting as close as I could and still focus, then cropped to get this composition.

This was shot with the same combo, the Canon 5D MkII and Tamron SP 90mm F/2,8 Di 1:1 Macro Lens.  I increased the F-Stop a bit on this one.  I set it to F/11.  Typically that is an aperture setting that would allow everything to be in focus, however depth of field is directly effected by how close we are to our subject, so even at F/11 I knew the DOF would still be very shallow.  I also shot this in Aperture Priority Mode on my Canon.  I bumped the ISO to 400 to give me a reasonable shutter speed, which was 1/160th.

Next time you are out shooting - whatever it is - don't forget to look all around you.  There may be shots everywhere!