Skydiving and Digital Photography

Many folks have been keeping their eyes on digital photography with a view to skydiving for some time. Historically, Digital Cameras have suffered from four problems – the relatively low resolution available, an inability to fire the shutter remotely, latency in processing the image and getting it to a memory card – and, of course, lenses.

At the APF conference in Cairns, I outlined a goal for digital photography in a skydiving situation. Six to twelve megapixel resolution, a remote release, able to burst several shots in a short timeframe and a choice of lenses – or at least one wide one! We are much closer to these ambitions now – although several other considerations, such as cost and weight, moved into the spotlight. Several manufacturers, including Canon, Nikon, Olympus and Minolta have all shipped cameras that meet the grade.

I bit the bullet and purchased a Canon 300D – a “sweet spot” in the marketplace for just this job.

Megapixels

The Canon 300D has a six megapixel (6MP) resolution. Describing megapixels is like comparing apples with bedheads – each manufacturer has a different way of puffing up the number to suit their marketing. In this instance, the 300D has some 6.5 million pixels, of which maybe 6.3 are used in producing a high resolution photo.

Sounds good. However, even ordinary 35mm has a greater resolution. Measuring images in terms of the number of horizontal lines that can be resolved, simple negative film offers about half as many lines again – and nearly four times the information that the 6MP shot contains. Slide film (colour positive) is higher again.

There are a multitude of other factors involved – the sharpening algorithms within the camera, recording into JPEG format loses quality immediately and so on – so good rule of thumb is that this 6MP product will shoot images that compare favourably with 35mm negative reprints at about 4×5 (100mm x 125mm). Want really high quality? Matching quality with a large-film camera (4×5) will require 210 (yes, two hundred and ten) megapixels. Depending on the manufacturer’s discussion of megapixels, somewhere in the 12 to 20MP range lies the camera which will outrun traditional 35mm film.

At the other end of the scale, compare the technique of lifting stills from MiniDV. Worth noting that the cameras which claim “megapixel stills” may well do that – but they don’t do so when recording to video. Performing the mathematics – capture size, video interlacing and so on – a digital video grab has about 0.6MP, and horrid colour saturation. It’s just not in the hunt.


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Canon EOS300D Digital Still

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Image lifted from MiniDV

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Canon EOS300D Digital Still, detail

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Image lifted from MiniDV, detail

Getting shots off in a hurry

Firing a traditional 35mm camera is easy. Exit and lean on the switch – it’ll keep rolling until you’re out of film. Digital is different – at some stage, it has to commit the image electronically – and this takes time. This latency is our major bugbear.

Although the 300D can fire 2.5 shots per second, it can’t maintain the rate. Nonetheless, it does much better than compact digital cameras by employing a “buffer” – a small cache of very high speed memory which holds around four shots. Once this buffer is full, there’s an enforced delay whilst it writes it to the memory card. The trick to getting lots of shots? Don’t fill the buffer!

Having a high speed memory card is the other part of the puzzle. Size is not everything; speed is. I purchased a SanDisk UltraII card, which my research indicated to be the fastest available – although leadership here is a moving target. 256MB will hold around 70 shots.

In terms of quality, the highest quality possible is called “RAW”. It’s uncompressed, and there’s an incredibly sexy piece of software (Adobe Photoshop RAW) for manipulating it. It’s also slow, largely because of the image size. It’s only suitable for Skydiving if you know you’re doing shot selection – RAW is completely unsuited to “spray and pray” burst photography.

So, most of us will use a high-speed Compact Flash card (“CF Card”) and the highest resolution JPEG quality in freefall – and once you understand the “take four shots and wait” rule, you can do very nicely. 33 shots in a seventy second freefall is my personal best.

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Lenses

Good news: the 300D uses “All* Canon EF lenses”. If you have an investment in existing Canon lenses, you should be in good shape – match the red dots on the lens and body, and away you go. The asterisk, of course, indicates not all – there are numerous issues with non-Canon EF lenses, such as those made by Sigma, so don’t assume your collection will be immediately compatible.

The Canon EOS 300D is also marketed in a package form, including an 18-55 lens. This is the first of a new generation of digital-friendly lenses – branded as “EF-S”, I kid you not – and indicated by the presence of a white square as well as the red dot. General feel of the quality of this lens is not high, and it was in fact described to me as “a $25 lens” by a photographic professional.

Bad news: these lenses won’t give you the same shot that an 18mm lens will on a traditional SLR…

Because of the smaller size of the sensor (analogous to the film in a traditional camera), lenses need to put the information in a smaller package. This results in a specification called the “Focus multiplier”, and it will remain until someone builds a sensor comparable in size to 35mm film. Canon are in the same boat as most manufacturers here.

    Equivalent lens sizes

Digital lens Traditional lens

16mm 26mm
18mm 29mm
22mm 35mm
24mm 38mm
28mm 45mm

To get the equivalent of a 17mm traditional lens for a Digital SLR, you’d need a 10mm lense. The Canon EF-S 10-22mm ships later this year, budget an extra $1,000 or so – because I think we’re all going to want one.

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Image Captured using EOS300D

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Image taken from MiniDV video, Sony PC101, 0.3x Diamond Lens

Getting ready to Skydive

Mounting

If you’re already using a Canon EOS for stills, it’s a straight swap – and you already know how to use most of the SLR features. You’ll sigh in relief when you see the rechargeable battery pack – although it contributes to the digital being some 50% heavier than the traditional EOS300. Nervous about your investment? An additional bungee might help.

The Electronic Shutter release

Unlike most other digital manufacturers – and indeed other pro models in the Canon range – the 300D utilises the standard 2.5mm stereo jack popular in the EOS range. Your existing stereo switch should work – Full marks to Canon.

Focus

Most digital cameras have a two-step switch – get focus, take shot. Given that our bite or tongue switch only takes the shot, locking off a manual focus with a rubber band or the ubiquitous gaffer tape does the job.

Away you go. It really is that simple.

Workflow

At the end of your skydive, you have a series of digital photos. You can’t simply give the customer your memory card as you would give them a can of film – What to do next?

Your options include:

1) Budget time for reading the images into a computer and writing a CD-ROM.

2) Put them into a computer and manipulate them using Adobe Photoshop or similar. Print them on your own inkjet printer, using the expensive paper.

3) Take the memory card to a Fuji Image Plaza or similar, where they have a self-serve machine for selecting shots and printing them on their half-million-dollar imaging printer.

4) Use an online service to image your photos and have them returned by post.

There are opportunities for retaining some more of the customer spend here. Images can be previewed on a TV or computer screen, and then printed in-house or shipped out to a processing house. If the customer elects to purchase just video not stills, it may be an opportunity to capture the stills sale after the fact. Some online services allow you to post photos against your account and a customer-specific PIN, so they can log on and make purchases later.

Want more? look at the EOS10D – higher price, weighs as much as three traditional camera bodies, but a nine shot burst. Still hungry? The EOS20D has 8.5MP, five frames per second, and a 23 shot burst. It’s heavier again. And costs more, of course. And don’t forget to check out the Nikon D70 – similar features, but similar limitations and an infra-red remote instead of a simple switch.

All that said: results indicate the 300D is good enough.

If you’re jumping for fun or with other skydivers, digital photography may now be for you – but if your camera flying is mainly Tandem video, you’ll need to come up with a workflow as simple for you as changing a can of film. The camera itself is fast, simple, and instant gratification. And yes, it will be obsolete by next year. So what!

Disclaimer: This article is published in the interests of education, and does not constitute a recommendation. Buyers should perform their own research before making a purchasing decision.

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