Joe and Mary Ann McDonald's

Wildlife Photography

November 2006

Question of the Month

What is the best aperture for Macro Photography?

The answer may surprise you!

Last April in Madera Canyon, Arizona, while our participants were busy photographing hummingbirds during our High Speed Flash Hummingbird Shoot, I had some free time to do an experiment. One of our participants had Canon's 65mm 1-5X Macro Lens, which provides up to 5X, or 5:1 magnification. I've often been tempted to purchase this lens but always felt that the lens wasn't really very sharp, and, at magnfications greater than 3:1 it was extremely difficult to use, In the field, it is practically impossible to do so. Still, I was curious whether or not the sharpness was there and, if not, was there an alternative using lenses I already owned to achieve magnifications of up to 3X.

Here's the test I did, and it is one that you can try for yourself to either prove what I'm saying, or showing you how small an aperture you can use for sharp images. I did this test using the 65mm Canon Macro, and then attempted to get a very sharp image with other lens combinations. For those, I did the following:

I mounted the lens/camera combination on a sturdy tripod, and focused on the same target area -- the inside of a small flower -- for each shot. I used two Canon 24 Twin-Lights for illumination, and at the close working distance the flash duration was fast. Moreover, I also used an electronic cable release and mirror lockup, so that there was no possible way that my firing the camera could create a vibration that might shake the camera and degrade the image.

With the 65mm 1-5X, I did not like the sharpness of images shot when the lens was fully stopped down -- I think that might be f11 or f16. I'm not certain because I don't own the lens to check -- even after the test I found this lens so cumbersome to use that I still am not tempted to buy one. At one f-stop from wide-open the lens was sharp throughout the magnification range. Very sharp. But again, the issue with this lens is workability and, aside from studio conditions, it is just plain difficult to use. I use this analogy: Imagine trying to place an object the size of a golf ball squarely in the middle of a disk the size of a garbage can lid, without being able to look around the lid to do so. That's basically what's happening with this lens at magnifications greater than 3X -- the lens' glass is so much larger than the subjects you're shooting that actually finding them, and getting them into the frame -- ie the center of the lens -- is extremely difficult and tedious.

To approach this type of magnification with the lenses I own, namely a 100mm and 180mm macro, I added tele-converters and extension tubes.

Starting with a 100mm macro lens, I did a series of shots, starting at f32 and continuing, in full-stops, until I reached f8. I did the same with my 180mm macro and was stunned at the lack of sharpness at f32. It looked as if I had slapped the camera at the moment of exposure, for the images looked that soft. F22 wasn't much better. F16 was reasonably sharp, but f11 was razor sharp.

I then did the same series of shots with both lens combinations with a 1.4X tele-converter, and the results were basically the same. Next, I added varying lengths of extension tube to the combination, placing the tubes behind the lens tomaximize the reproduction ratio, then adding the tele-converter to magnify the final result. Again, f16 was marginally sharp, and f11 was razor sharp. F32 was useless.

My conclusions - Depth of field at very close working distances is extremely narrow, regardless of the aperture in use. The discernible depth, the appreciable differences in depths between an image shot at f32 and f11 at extreme magnifications was not worth the cost in the loss of sharpness. When I'm now doing macro images, especially those greater than about 1.5:1, I'm far more likely to use f11 or, at most, f16, than I will use f22 or f32. In fact, I'm pretty much dismissing f32 as a non-usable aperture for this type of work.

I'll still use small apertures like f22 on my wide-angle shots, however, and for a reason. An image shot with a wide-angle usually encompasses a greater scene -- think of an entire tree -- than does a macro lens with a tele-converter and extension tubes added -- think of the pores in the leaf of that tree. While small apertures with wide-angle lenses create diffraction and potential softness in an image, I don't think you'll notice it nearly as much as you will when looking at, and trying to appreciate, micro details on macro subjects.

You might wish to try this test for yourself, but if you do, be sure to use an electronic flash, mirror-lockup, a tripod, and electronic cable release to make sure there is no photographer-induced degradation of the image.


Previous Questions of the Month




 Camera Techniques

 In the Field

Do You Need a
Big Printer?

Can a Wimberley Head be used with small lenses?

Is a Trip to Antarctica
Worth it?

 Is there an easy way to level a camera for panorama shots?

 Why is Yellowstone the best for wildlife photography in the US?

 Why must you have
at least 2 digital backups

 Wildlife Models
Is there anything new
to shoot?

 Is the New Wimberley head worth having?

  What is our Digital Workflow in the Lab?

 Who should go Digital,
and when?

 What is our initial Digital Workflow?

Is Shooting in the RAW format worthwhile?

 Can you match the Histograms?
 How do I keep track of Digital Files?

  Is Digital Manipulation - a benign alternative to interacting in the natural world?

What is DEC? 

How can you capture a sharp image and angel hair on a windy day?  

 Is the Mark II the ultimate wildlife digital camera?

  Does the Visibledust cleaning system really work?

What do we really think about digital photography?

 What do we think of the Canon D30 digital camera?

How long will film be around? 

  The Sunny 16 rule -- is it worth knowing today?

 What is the Difference?

 How do we meter White?

 How can you save your shoulders?

  How do you shoot silhouettes?

 How would you meter these challenging images?

Why should you know Manual Mode? 

How would you meter these images?

 What is the best season to do a photo safari in East Africa?

Which Mountain Park is better for wildlife - Denali or Torres del Paine?

What is the best Car Window Mount? 

  How do you make things happen in wildlife photography?

 What are our Five Favorite Shooting Locales?

 What is the Big Lie?
Tfhe truth about Kenya's Tourism--it is SAFE!

 Which binoculars do we just love to use?

 What is the best
Game Caller?

 What is our Favorite bird-shooting location?

 How Easy is Whale Photography?

  How do we carry our film when traveling?

What Film Lab do we use, and why? 

 How can you attract insectivorous birds to your feeding stations and bait sites? 

How can you reduce contrast and the effect of wind for flower and macro photography?

 Is an L-Shaped Camera Bracket worth the Money?
You bet it is!

 Using Zoom lenses with tele-converters and extension tubes -- can you use both together?

 What the heck is the Scheimpflug Law?

  Reciprocity Failure

 What is the Best Composition?

 Are Image Stabilization Lenses Worth the Money?

 Hyperfocal Distance

  How do you determine distances?

 Should you have a depth of field Preview button on your camera?

 Flash and Tele-flash Techniques

 What is the most versatile remote release camera firing system?

 What the heck is a Plamp?

 What is the best flash for closeup and
macro photography?

 How do you shoot high-speed action images?
 How did I photograph that flying wasp?

 What is the Fotronix's
Flash System?

What is the Most Important thing you can do before a Workshop?

How did I shoot the gliding Sugar Glider?
 Is NANPA for you?  What is NANPA and how will it benefit me?

 Is it time for a summer NANPA Summit?

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