Saturday, March 22, 2008

Get out and Shoot!

Spring has Sprung series 1-2
Originally uploaded by Dalantech.
Don’t wait for perfect conditions to go shooting macro; in fact some of the best days to go looking for critters are when the weather isn’t ideal. Low temperatures and partly cloudy skies can create a “stop and go” environment for some insects (that’s how I’ve been shooting Miner Bees above life size lately). As long as the sun is out they have the energy to move, but as soon as it goes behind the clouds or they land in the shade their metabolisms take a nose dive and you can get really close.

Wind can be a blessing and a curse. I had to delete a lot of frames after shooting a pair of mating Hoverflies due to the wind. But the breeze also kept them pinned down to the leaf they were on –all I had to do is wait for the brief pauses in the wind to take my shots.

So get out into the big blue room with the big yellow ball on days when the weather is poor. You might be surprised at what you find…

Monday, March 17, 2008

Earth Calling Gary Fong

Miner Bee March 2008 series 2-1
Originally uploaded by Dalantech.
You really should consider making a set of diffusers for the MT-24EX macro twin light from the same plastic that you use in the Puffer diffuser -I hot glued a couple of them to my flash heads and that's the lighting that I used for the image attached to this post. A three times life size shot with an MPE-65mm macro lens and a diffused MT-24EX that looks like I shot it using natural light...

Thursday, March 13, 2008


Miner Bee March 2008 series 1-3
Originally uploaded by Dalantech.
I often get asked “What’s your keeper rate?” so I thought I’d share the statistics for a single shoot –the miner bee included with this post. There was a little wind, and I’m really picky about the composition of my images (that includes the area of sharp focus). So keep in mind as you read the numbers that I’ll delete images that are close to being the same, or if a photo is even slightly off I’ll can it. Someone once said that the difference between a professional photographer and an amateur is that a pro throws away more photos…

I posted a six image set of that miner bee on Flickr. I have another 31 images and some of those are duplicate compositions so I’ll end up deleting a few more. But I shot a total of 117 frames of that bee, recomposing for every image, before it got tired of me and flew off. I’ll probably end up with a 10% keeper ratio once I finish editing and or deleting the remaining images. But for an image like the one I’m including with this post I’ll gladly take a 1 in 20 keeper rate…

Thursday, March 6, 2008

Getting use to the 40D

Like most of the gear I write about on this blog this is not a review –I’m not qualified to give you an in-depth review of any camera body or lens because I haven’t used them all. Instead I’m going to tell you about the problem that I had in switching from the Xti (400D) to the 40D.

The Xti’s light meter consistently under-exposed everything and I was use to it. No problems with raising the exposure in post by about -1/3 (if necessary) because colors naturally saturate when you under expose with a digital camera, and since I cut my teeth on Fujichrome Velvia back in the film days I liked the effect that under-exposing has.

Unfortunately, at least for me, the 40D’s light meter is very accurate –sometimes a little too accurate. Images are either dead on, or a little over-exposed and the level of over-exposure depends on how much natural is available. The end results are what seem to be inconsistent exposures when shooting flash macro at 0 FEC –sometime it works, and when it doesn’t the area in the scene that’s blown out varies.

Like an idiot I switched cameras and immediately changed my style by shooting at ISO 200 instead of staying at ISO 100 and it made the problem worse…

I didn’t think that going from ISO 100 to 200 would make much of a difference –it’s just one stop and when shooting flash macro I’m usually 3 or 4 stops below ambient anyway. But for every one stop change in exposure the amount of light coming through the lens either gets cut in half or it doubles (depends on the direction of the change). In going from ISO 100 to 200 the amount of light coming through the lens from the flash stayed the same –the flash duration simply dropped in half (which was my motivation for going to ISO 200 in the first place since it would be easier to freeze motion with a faster flash). But the amount of ambient light coming through the lens DID double, and that’s what was causing my inconsistent problems with blown highlights in my images.

Sure, I could set the FEC to -2/3 and continue to shoot at ISO 200 with no blown highlights. But the subject would be too dark and I’d loose too much detail. So at ISO 200 I can set my FEC to -1/3 and deal with some minor over-exposure in the highlights or drop down to ISO 100 to eliminate it. I still have to set the FEC to -1/3 at ISO 100, but I don’t think it’s a metering issue with the camera: I’m using the MT-24EX and when you shoot with two light sources one of them is bound to cause problems depending on the scene. If I were using a single flash head I could probably set the FEC to 0…

The photo I’ve attached to this post was taken at ISO 100 with the FEC set to 0 and there is some minor blown highlights in the background –you can’t see it because I adjusted the exposure in post to pull it out. As long as the blown highlights are minor, and not on the subject, it’s an easy fix. This next shot was taken at ISO 100 and -1/3 FEC and the exposure was dead on:

Fly at 4x

Moral of the story: If you run into a problem then blame yourself first, and not the gear…

Saturday, March 1, 2008

The Sunny 16 Rule for Macro

Signs of Spring series 1-2
Originally uploaded by Dalantech.
When I wrote about exposing for two light sources I explained how I had exposed the image for the sky and for the flash, but I didn’t fully explain how I was using the ambient light or how easy it is to do. So I’m going to give you my Sunny 16 Rule for Macro, but first an explanation of what the Sunny 16 Rule is…

If you are shooting on a bright sunny day then you can set your Fstop to 16, and your shutter speed to the reciprocal of the ISO that you are using. So if you want to shoot at ISO 100 then your shutter speed is 1/100 of a second. Need to shoot at 1/200? Then set you ISO to 200. With those settings you’ll get pretty close to the ambient exposure on a bright sunny day –when shooting toward infinity…

You can easily shift the exposure around, you just have to make sure that you keep the ratio between Fstop, shutter speed, and ISO the same. Want to shoot at F11 instead of F16 and stay at ISO 200? No problem –you can increase your shutter speed by a stop to 1/400 of a second (it would have been 1/200 at F16) to eliminated the stop you gained by moving from F16 to F11. Or if you wanted to set your Fstop to 11 and your ISO to 100 then you could increase the shutter speed to 1/200 of a second. Piece of cake…

But what about shooting at life size –does the Sunny 16 Rule still work? It does, but you have to take into account the effective aperture you’re shooting at when the lens is focused at life size, which is two Fstops higher than what you have the camera set to. If you have your camera set to F16 then the effective aperture at life size is actually F32. You’ll have to make up that two stop loss and if you wanted to keep your shutter speed at 1/200 of a second you’ll have to set the ISO to 800…

But lately when shooting at life size I’ve been using F11 which is effectively F22. That’s only one Fstop higher than 16, and if I want to keep the shutter at 1/200 of a second then all I have to do is set the ISO to 400 and on the 40D that’s not a problem –and with good noise removal ISO 400 isn’t an issue on most cameras (I use Noiseware Professional). So with the camera set to F11, 1/200 of a second, and ISO 400 I am pretty close to the ambient exposure for the background –but not the subject! Since the sun is the light source, and it’s so far away, the number of photons per square centimeter that are bouncing off of things in the scene and back into the camera is the same, no matter what the distance between them and the camera is. But distant objects will reflect more light into the camera than objects that are close simply because the surface area of distance objects is larger. Larger objects reflect more sunlight –a no brainer. So the farther away an object is the better the exposure for that object will be with the Sunny 16 Rule.

This is where the flash comes in. Since the ambient light is exposing the background it’s a simple matter of putting the flash into E-TTL mode and letting the camera determine the exposure for the foreground. The end result is a nice balance between the ambient sunlight and the flash. You have to diffuse the flash, and the better the diffusion is the smoother the transition between the flash light and the sunlight will be. It’s also best to under expose a little with the flash.

The image I’ve included with this post is an example of using the Sunny 16 Rule for Macro, and it’s the third time I’ve used it in a blog post. As soon as I have another example of this technique I’ll change the image ;)

A final note: At life size I could set the Fstop to 11 (effectively F22), the ISO to 200, and the shutter speed to 1/100 of a second to expose for the background. But when using the Sunny 16 Rule for Macro I’m shooting close the ambient exposure for the subject, how close depends on the angle of the sun –if it’s over my shoulder then there is a lot of sunlight hitting the subject and coming right back into the camera and I might not be able to freeze all motion with the flash. I still need to experiment with shifting the shutter speed instead of the ISO to see how much I can lower the shutter speed and still get a sharp subject. If you want to experiment on your own one way to do it, and to see the effectiveness of the ambient light, is to set up your camera and take a few shots without the flash turned on. If the subject is completely black in the frame then the flash will freeze the motion for you even if you’re using F11, ISO 100, and 1/50 of a second.