So I finally got around to taking that trip to Yellowstone that I was talking about back in May. Rather than going in late August 2009, as I had planned, I actually ended up going last month (that’d be March, 2010). For those of you not familiar with weather in the Northern Hemisphere, that meant going in what amounts to the dead of winter, instead of the height of summer — and as far as I’m concerned, it was the best thing that could have happened to the trip.

While we didn’t have the Park to ourselves, exactly, we were much closer to it than we would have been in August. And wildlife was much easier to spot as well. Although I didn’t snag a shot of one of Yellowstone’s coveted wolves, I did get some nice images of the local bison, coyotes, birds, etc. All in all, a great trip, and I highly recommend a winter excursion to the park for anyone who hasn’t done it already. You won’t be disappointed.

But that’s not my purpose here. In my earlier post I made soem guesses about what I thought my photography habit was going to set me back, in terms of consumables (in the form of storage), for the trip. In that post I had guessed that I’d fill two 4GB cards, which I thought would be fine for my relatively low-resolution (by 2010 standards) DSLR.

As it turned out, I was a little low.

Over the course of nine days, I took a total of 2,299 frames, equivalent to about 64 rolls of 135, and consuming just under 20GB. Just sorting through then and making a ‘first cut’ is a project in itself.

Part of the reason I ended up taking so many frames (and I’m using the word “frames” rather than “images” carefully here) is because I had brought my laptop along with me on the trip and as a result knew I didn’t have any reason to conserve storage space. The limiting factor on my shooting wasn’t storage, but instead camera batteries. With a 4GB and 8GB card, I could easily shoot all day and then dump the contents to my laptop at night for storage and immediate backup to a DVD.

This led to an immediate change in my shooting style that I never would have made, if I’d been shooting film or even using the digital without the hundreds of gigabytes of disk storage that the laptop represented: I turned on three-frame, +/-0.5 EV bracket mode on the first day and never turned it off. That’s something I’ve never felt rich enough to do on my film Maxxum.

So those 2299 frames really represent something like 800 images (I did take a few without bracket mode, so that’s a low estimate), much closer to my initial estimate of 20 or so 35mm rolls worth. It’s just that, rather than only having one frame for each image, with the digital I have two “insurance” frames, in case my judgement of the light was a bit off or I just decide that slightly lighter or darker is preferable. Although not earth-shattering by any means, I do think the bracketing saved a few marginal images that otherwise would have been garbage if I’d only had the “center” one. And that’s enough to make me a pretty happy photographer.

In a few months (late August), I’m planning on heading to Yellowstone National Park for a week’s worth of outdoor recreation and, I hope, many opportunities for photography in one of the most beautiful parts of the U.S. Since this is the first major photographic excursion I’ve gone on with a DSLR instead of film, I’ve been putting some thought into the contents of my gear bag.

At the moment I haven’t decided whether or not I’ll be bringing a laptop with me on the trip. If I decide to forgo a computer, I’ll either need to buy a lot more CF capacity than I have now, or get something to download the cards onto when they get full.

The price per GB on CF cards varies based on the speed of the card and the total capacity, with larger cards generally costing more then the older, smaller-capacity cards. The best deals currently going seem to be on the 100x (15MB/s) and 133x (20MB/s) cards, with a significant premium for the 266x (40MB/s) and faster UDMA varieties.

I found a 4GB 133x Kingston card for $15, and an 8GB 133x for $25, both at Adorama, and the latter with free shipping. That works out to around $3.13/GB — not too shabby, but not exactly disposably cheap.

It’s more interesting to consider the cost on a per-frame basis: each click of my Minolta Maxxum 7D’s shutter (when in RAW mode) consumes about 8.6MB, so if I were to use memory cards the same way I used to use film — treating it as a consumable, at least for the purpose of my trip — I’d be paying about 2.6 cents per image. By comparison, bulk-loaded Kodak Portra (my color film of choice) is around 3.3 cents per image, and that’s just for the stock, neglecting processing costs and any waste.

I knew digital photography was cheap, at least in terms of running costs, but that surprised me. CF cards are so inexpensive today that I could use them not only for in-camera storage but also as my archive copy, and I’d still come out ahead.

In terms of ‘film rolls,’ which is still a unit that I find myself thinking in, each 4GB card holds about 465 images or 13 35-exposure rolls. (I never shoot more than 35 frames on a roll of film, because I store them in binder pages that take 5-frame strips. Nothing more annoying than having one or two extra frames at the end of a roll that don’t fit into the binder page, forcing you to waste a second one.) If I were planning on taking my film camera, I’d probably bring 20 or 25 rolls, so I think two 4GB cards will probably do the trick.

Of course, I’ll probably take many more photos with a digital than I would with film, so it makes sense to budget more. It’s an open question in my mind whether I’ll really end up with more ‘keepers’ after the first cut than I would with film; in other words, do all the additional shots I take when I’m shooting digital actually amount to more good images, or do they just decrease the S/N ratio? One of my goals is to try and figure that out.