DSLR 101ism

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Joined the old Digital Single Lens Reflex camera club recently (hello video capable Canon 7D), which has meant learning about photography (shout out to photo guru Dan Murphy), and about technologies that bridge the old and the new. And haunting Ebay a bit more than usual.

canon7d_image
To DSLR or not to DSLR?
The benefits of digital image recording ( cost / workflow etc ) combined with the advanced light controls of a SLR camera – make DSLR cameras great for photographers, and now that they’re often capable of good quality video, DSLRs are lluring in a lot of film-makers too. It’s not all win though – videomakers expecting DSLRs to have the same ease of shooting will be disappointed. Weighing it up for those interested in video, David Torcivia has summarised the pros and cons over at Poetzerofilm.com:

Nay
Ergonomics – too light / small / awkward screen and controls
Moire and Aliasing – skipped lines in video, during process to shrink large image down to video size
Shutter Rolling – fast moving objects can be in different places in the same frame
Resolution – they don’t actually shoot as well as advertised
Compression – Canon records to lossy H264 format ( which needs processing before editing )
Audio – terrible on DSLR, need to record externally ( eg with Zoom H4n) + sync (pro-tip: Plural Eyes! )

Yay
Ergonomics – The small size can also mean shooting easily in cramped spaces, and more discreet filming.
Depth of Field – Hey look, it’s blurry in the background! Beautiful, but as the web fills with it, David helpfully notes:
“Don’t wear out the effectiveness of a shallow shot by making an entire “test” film filled with nothing but micro DoF. Shallow depth of field is just another tool in the cinematographer’s box to better tell a story. It is not a crutch or a gimmick to sell a shot or a product, an idea which cheapens the art.”
Low light – Zowie! For the price, DSLRs can shoot in hearts of darkness that video cameras cannot even see. Believe.
Price – Fantastic quality and value.
Photos – Oh yeah, do they do those too – 10 stops of dynamic range, full RAW files, 18 or 21 Megapixels – all great for timelapse .
Lenses – The variety of glass available for DSLRs vastly outweighs that possible for video cameras ( hello eBay, or hello rent-a-lense for important occasions )
Media – Tapeless workflows. Drag n drop, rather than slowly capturing footage.

Plunging In…
So in the end – disregarding all the science and numbers, you’ve found yourself swooning over luscious, colour-ripe non-grainy video shot by someone in such low light conditions that you’d packed away your video camera an hour ago. THAT’S OKAY, you’re with friends.

And if being the new owner of a DSLR finds you bewildered by the array of options available – Wikipedia’s photography page is incredibly useful for getting up to speed with photographic terms and principles, and pointing to a huge range of future learning. For starters you’ll be needing to understand :
Aperture – the lens opening, measured as the f-number ( eg f2.8 ), which controls the amount of light passing through the lense.
Shutter speed – time the imaging medium is exposed to light for each
ISO speed – The higher the ISO, the greater the sensitivity to light.

There’s plenty more, and plenty more starting points too..

Which Lenses To Get?
If you need, you can actually mount cinema lenses to a DSLR, using add-ons from hotrodcameras.com. For most people though, the existing range of photography lenses will be a vast enough jump in quality from handheld video. Things to note? Lenses with lower f-numbers are preferable ( and more expensive ). Aside from lenses specific to your camera, there are also a wide range of cheap adaptors that can be fitted to any DLSR, which will enable lenses from other manufacturers to be used ( functions like auto-focussing can be lost with some of these though ). And one more complication – the Canon 7D doesn’t have a full frame sensor, and it’s smaller proportion of a frame means you have to multiply the below numbers by 1.6. In other words, a 50mm lense on the Canon 7D is the equivalent of a 80mm lense (50 x 1.6), and the perspective it brings.

50mm - The classic lense. A lense this size renders perspective in a way similar to how a scene is perceived by the human eye.
Wide Angle Lenses ( Below 35mm ) – allow you to fit more in frame from closer range ( think fish eye), but exaggerate distance between objects and can distort.
Telephoto Zoom Lenses (Above 70mm ) – allow magnification of distant objects / skateboarders / small furry animals etc ( though tends to compress distance between objects ).

Macro lenses – Want to shoot close-ups? These are the lense for you – or – seek out extension tubes or adjustable bellows ( both which are placed between another lense and the camera, changing the dynamics so that close-up is possible ), or get an auxiliary close-up lense to attach to the front of a lense, or get a reversing ring ( an adaptor that allows the lense to be attached to the camera backwards, which creates extreme close-up vision ). http://en.wikipedia.org/wiki/Macro_photography

( See also Tamron’s guide to lenses, and Cambridge in Colour about lense focal lengths, zooms vs primes etc )

A range of trick filters which can be added onto existing lenses for various effects ( find out what diameter your lense is ( eg 72mm), to find appropriately fitting add-ons ). And then there’s the tilt-shift lenses ( see also lensbaby ), and other trick lenses… ( on it goes.. ).

Time Lapse?
The image quality is significantly higher quality for photos in DSLRs, than it is for video. Correspondingly, animating a series of high quality photos in sequence for timelapse bumps the ‘video’ quality up even higher. Strangely the Canon 7D doesn’t have an automated sequencing function built in, and needs an external ‘intervalometer’ to do this. Canon sells one for around $200. Hong Kong vendors on Ebay sell adequate imitators for $30. There’s also an iPhone app for remote triggering / viewing of photos – but it requires the camera to be attached to a computer ( not great for out and about shots.. )

Stability… Later…
Someone walking around with a handheld video camera, will produce jerky footage, no matter the camera… but especially so with a small camera like a DSLR,, and then there’s the additional desire to avoid troubles like the Jelly Vision mentioned above. The image quality is good enough though, that a whole industry has spawned in providing ways to minimise trouble. And so…

Next DSLR Update : Stabilisation, active filming + Steadicam Systems ( from pro to DIY )

Autobot Roulette:

7 Comments

  1. Im sold the cheque is in the mail!

  2. great explanation of what you need to know :)

    we have been having a ball with our 5DmkII.

  3. Thanks Jasper – and full frame in the house! I’ll bet you are enjoying… : )

  4. Pingback: skynoise » Steadicams + Video Stabilising Systems

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  7. Seem your site have good info about DSRL guide, I search google and found your site reach top position in it.

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