Posted by Jim Hackley on October 22, 2010 at 1:27 AM
I experienced one of those fun moments when I was photographing a Flame Skimmer dragonfly during a rainstorm. I was looking out the back porch checking out the rain when I noticed this bright orange dragonfly land on a agave cactus. It made such a colorful contrast that I had to get a photograph of this. I was getting some nice photographs when all of a sudden I saw a quick blur out of the corner of my eye. I looked up from the viewfinder, over the camera and to my surprise a Costa Hummingbird had landed on the agave just in front of the the dragonfly. At first I was just admiring the hummer then I remembered to start taking pictures and was able to get off about 10 shots before the Costa flew away.
This was a nice experience but it brought up a depth of field problem. The hummer was about 1 foot in front of the dragonfly so maybe this was too much of a distance. I was about 10 feet in front of the agave cactus. After reviewing the images I was wondering if I had any options of getting both hummer and dragonfly in focus.
My thoughts and questions are:
1. Would a small aperture like f22 worked for that distance?
2. Focus on hummer for one shot, focus on dragonfly for one shot then blend the two images. I have never done a blend image but I read and see here on NPN how the landscape photographers do this.
3. Pick the closer subject and focus on that?
I would be interested to hear what others think. Just trying to think what I can do for the next time something like this comes up.
Thanks for any feedback on this.
Jim
Update: I was using a Nikon D300s with a Nikkor 300 f4 lens and a Nikon TC 1.4E II.
Posted by David Bostedo on October 22, 2010 at 8:51 AM
Jim - My thoughts on the answer :
1) Possibly. Your DOF is controlled by your focal length as well as your focus distance and aperture (and sensor size, but indirectly). And your apparent DOF in the image is controlled by your camera sensor size as well. Apparently your focus distance was 10 feet - can you fill in the other items? You can use online DOF calculators (like DOF Master) to see what kind of difference going to that aperture would make.
2) Blending for focus can be difficult, because it affects everything at that distance from the camera, including the various parts of the cactus. There are programs that do this automatically (including Helicon focus and newer versions of PS I think) so it's definitely an option. But I'd want to go the software route, since you have some complexity. If there were clear section of the image at just a couple of distances it would be easier, but software is your best route.
3) This looks like the option you've posted here, and it depends on what your going for. To get both in focus with as shallow a DOF as possible, you'd probably want to focus slightly past the front object (hummingbird in this case) since DOF is a little asymmetrical. But I think in actual shooting conditions on animals, I'd rather have enough DOF that I can focus on the front object, and not fiddle with manual focus.
Posted by Barry Southon on October 22, 2010 at 12:41 PM
Jim
A very interesting question. You don't detail the equipment your using this may well affect the approach. Could focusing on one then lock and refocus on the other subject be a possibility?
Thanks for sharing the subject and I really like the image.
Posted by Richard Ditch on October 22, 2010 at 4:49 PM
DOF gets very narrow as subject magnification increases - this is the fundamental dilemma of macro photography. Its hard to judged from this image how much depth distance there is between your two subject here, but I think it was likely too much for your 300 (plus converter?) to get them both in good focus, even at f/22. And even if f/22 did give sufficient DOF here it might have degraded image quality more than would make you happy with the result.
To exploit the maximum DOF in any situation you need to focus part way between the subjects (I can never recall if it is 1/3rd or 2/3rds of the way between).
Posted by David Bostedo on October 22, 2010 at 6:16 PM
Richard -- the "rule" is 1/3, but that goes out the window sometimes too as you hit different extremes of lens and focus distance.
Jim - For your setup, the DOF at f/22 is about 0.13 feet, or only about 1.56 inches. This is approximate given the exact focus distance and final image size, but it's definitely small no matter what.
Posted by Nate Chappell on October 23, 2010 at 12:37 AM
Hi Jim,
I think you must have been quite bit farther away than 10 feet. Photographing at that effective focal length (630mm) I'm confident from experience photographing hummers that the bird would have been quite a bit bigger in the frame than it is.
If, (and this is just for example), you were 30 feet (10 yards) away with that setup you have 1.34 feet of depth of field at that focal length at F22. (From www.dofmaster.com) Then if you focused halfway between the bird and the insect you would have enough depth of field to get both in focus if they were 1 foot away from each other because you would have .67 feet or so of depth of field in each direction and you would need 1/2 of a foot in each direction.
Estimating the distances when working in the field is difficult, but in this situation I certainly think it would have been worth trying a high F-stop if you wanted to get both in focus. If you have the time you can also use the depth of field preview.
The 1/3 rule doesn't work with longer focal lengths at relatively close distances. It is much closer to 1/2 in those situations.
Posted by Jim Hackley on October 23, 2010 at 6:26 PM
Nate, you are right, went back to my picture, went back outside and it was about 30 feet. It certainly seemed closer looking through the viewfinder. Now if I can only remember to do those things when the situation comes up again.
Thanks for all the good information.
Jim
Posted by David Sewell on November 1, 2010 at 8:44 AM
Hi Jim,
Rather than use f22 I would suggest you take two photos, one with the bird sharp and the other with the dragonfly sharp. There are various commercial programs that will allow you to blend images, but CombineZP is a free download off the internet and is relatively easy to use. Now all you have to do is wait for both animals to land at the same time again...
David
Posted by Jim Hackley on November 3, 2010 at 4:07 PM
David, thanks for the software tip.
Jim
Posted by Audrey Rice on November 4, 2010 at 4:55 PM
I enjoyed reading all the technical tips on how to get this sharp in camera, but when I'm in the field I'm to excited to be doing all that math. I'd opt for blending the two images into one. As long as you use a tripod and don't move the camera it should be pretty easy to do in Photoshop using the photo merge command. (File > Automate > photomerge). Truth be told, I get much better results doing it manually - but that's just me.
Discussion
9 repliesThis was a nice experience but it brought up a depth of field problem. The hummer was about 1 foot in front of the dragonfly so maybe this was too much of a distance. I was about 10 feet in front of the agave cactus. After reviewing the images I was wondering if I had any options of getting both hummer and dragonfly in focus.
My thoughts and questions are:
1. Would a small aperture like f22 worked for that distance?
2. Focus on hummer for one shot, focus on dragonfly for one shot then blend the two images. I have never done a blend image but I read and see here on NPN how the landscape photographers do this.
3. Pick the closer subject and focus on that?
I would be interested to hear what others think. Just trying to think what I can do for the next time something like this comes up.
Thanks for any feedback on this.
Jim
Update: I was using a Nikon D300s with a Nikkor 300 f4 lens and a Nikon TC 1.4E II.
1) Possibly. Your DOF is controlled by your focal length as well as your focus distance and aperture (and sensor size, but indirectly). And your apparent DOF in the image is controlled by your camera sensor size as well. Apparently your focus distance was 10 feet - can you fill in the other items? You can use online DOF calculators (like DOF Master) to see what kind of difference going to that aperture would make.
2) Blending for focus can be difficult, because it affects everything at that distance from the camera, including the various parts of the cactus. There are programs that do this automatically (including Helicon focus and newer versions of PS I think) so it's definitely an option. But I'd want to go the software route, since you have some complexity. If there were clear section of the image at just a couple of distances it would be easier, but software is your best route.
3) This looks like the option you've posted here, and it depends on what your going for. To get both in focus with as shallow a DOF as possible, you'd probably want to focus slightly past the front object (hummingbird in this case) since DOF is a little asymmetrical. But I think in actual shooting conditions on animals, I'd rather have enough DOF that I can focus on the front object, and not fiddle with manual focus.
A very interesting question. You don't detail the equipment your using this may well affect the approach. Could focusing on one then lock and refocus on the other subject be a possibility?
Thanks for sharing the subject and I really like the image.
To exploit the maximum DOF in any situation you need to focus part way between the subjects (I can never recall if it is 1/3rd or 2/3rds of the way between).
Jim - For your setup, the DOF at f/22 is about 0.13 feet, or only about 1.56 inches. This is approximate given the exact focus distance and final image size, but it's definitely small no matter what.
I think you must have been quite bit farther away than 10 feet. Photographing at that effective focal length (630mm) I'm confident from experience photographing hummers that the bird would have been quite a bit bigger in the frame than it is.
If, (and this is just for example), you were 30 feet (10 yards) away with that setup you have 1.34 feet of depth of field at that focal length at F22. (From www.dofmaster.com) Then if you focused halfway between the bird and the insect you would have enough depth of field to get both in focus if they were 1 foot away from each other because you would have .67 feet or so of depth of field in each direction and you would need 1/2 of a foot in each direction.
Estimating the distances when working in the field is difficult, but in this situation I certainly think it would have been worth trying a high F-stop if you wanted to get both in focus. If you have the time you can also use the depth of field preview.
The 1/3 rule doesn't work with longer focal lengths at relatively close distances. It is much closer to 1/2 in those situations.
Thanks for all the good information.
Jim
Rather than use f22 I would suggest you take two photos, one with the bird sharp and the other with the dragonfly sharp. There are various commercial programs that will allow you to blend images, but CombineZP is a free download off the internet and is relatively easy to use. Now all you have to do is wait for both animals to land at the same time again...
David
Jim
Beautiful image by the way! I love the colors.