These are more snowflake photos. This time they were taken on the night of March 12/13 in Casper, Wyoming, USA.
Conditions were such that the snowfall earlier the evening of the 12th generated good-looking "stereotype" snowflakes. I wasn't able to get out to capture and shoot them as they were falling, but I managed to go out later and take these photos of flakes I scooped up from the upper layer of the new-fallen snow.
As with the other gallery, these photos were taken using a Canon 20D with the MP-E65 Macro lens. For these shots, the lens was set to between 4X and 5X magnification.
The flash used was the Canon MT-24EX mounted to the front of the lens. For many of the shots, I tried several variations of flash ratio between the two flash heads. For some of the photos I've posted, you'll notice that two shots in a row are of the same flakes with the only difference being that the flash head ratio was changed between shots. Since my "tripod" arrangement was not very steady, pressing the buttons to adjust the ratio often shifted the aim slightly accounting for the shift in the positions of things between the two shots.
The arrangement was thrown together quickly to take advantage of the good snow conditions and was less than ideal.
The camera/lens was mounted on an inexpensive and unstable tripod aiming straight down. A makeshift table was built using a few odds and ends including a stack of cardboard box pieces to adjust the height of the "stage". A wedge-shaped piece of wood was jammed under one side of this table to allow for fine adjustment of its height.
The snowflakes were gathered by scooping off a bit of the upper layer of the new-fallen snow onto a paint color sample card (this accounts for the blue color of the backgrounds). I would then tap the card to try to get the flakes to separate from each other as much as possible. Then I'd just look at the card and when I found a good-looking candidate, I'd slide the card in under the front of the lens, on top of the stack of cardboard pieces and then look through the eyepiece of the camera and carefully move the card around until I found what I was looking for.
I'd adjust the focus of the lens and then fire off a shot.
I used mirror lockup and a wired cable release this time to try to reduce camera shake. This may not be totally necessary because of the high shutter speed and the use of flash (presumably fairly brief flash pulses) to provide virtually all of the illumination.
I crudely taped an LED flashlight to the front of the flash support ring to provide a bright "modeling light" to allow for better viewing and focusing. Keep in mind that even though the lens allows for full aperture metering (and focusing), at 5X, the effective aperture is f/16.8 which makes for dim viewing unless you can get some serious light onto the subject!
In order to keep the flakes from melting, all of the shooting was done outside at a temperature of around +7 degrees F (-14C). When examining the flakes on the card or focusing, I had to hold my breath to keep it from melting the flakes immediately.
The cold did make battery capacity drop significantly requiring two sets of batteries in the flash and a swap of the camera’s battery as well. Only 183 shots were taken which would ordinarily not have required that the batteries be changed.
For future attempts at this, I’d like to have a much stouter support for the camera and some kind of adjustable “stage” for the flakes. I would also like to use an even smoother surface onto which the flakes would be scooped to yield a less distracting background.
I do find that using a background with some reflectivity is good, however, because it helps to keep the flash metering more consistent so that less adjustment of flash exposure correction (FEC) is required. With a very dark background, the exposure naturally varies depending on how much of the frame is occupied by the flakes themselves.
I think a plain clear glass microscope slide may be a good thing to capture the flakes on. I’ll need to expose the slide(s) to the outside cold temperature longer, however, because the heat capacity and thermal conductivity of the slides will be much higher than that of the cards I was using. It’s obviously very important that the background doesn’t melt the flakes!
By using a glass slide, I could try a few things. First, the slide could simply be placed onto a colored background of my choice but due to the thickness of the slide, that background would be very out of focus and the slide itself very smooth resulting, hopefully, in a less distracting backdrop for the flakes.
Also, using a clear slide, I could try to backlight the flakes as well by mounting the flash head(s) underneath the slide.
Anyhow, that would all be nice – but who knows if I might have something like that available when the next good snow hits :)