Thursday, April 26, 2012

Speedlites vs Studio Flash

I've been using flash a bit more these days, and was wondering whether to replace my pair of old Bowens Monolite 400D's, bought a few years ago secondhand, or whether to expand my Speedlite system.

Problem is, as excellent and (so far) reliable as the ancient Bowens are, they are big and bulky units which cannot be used on location. I already have 2 Nikon SB-800 Speedlites and theses offer considerable advantages:
  • Compact and light
  • Battery power means location use (I also have SD-8a battery packs for quicker recycling)
  • Works with Nikon Creative Light System (CLS) so exposure and power of each light can be controlled wirelessly from my D7000
Of course they are not as powerful as the Bowens, but it's incredibly difficult to judge from specs alone, and there is no real comparison I could find on the web. Trouble is, studio flash power tends to be quoted in watts, but this is really a measure of the electrical energy delivered to the tube, not the light output, which will vary depending on the efficiency of the tube and reflector. The Bowens are apparently 250W, according to this.

So I did a 'real world' test for myself, I fired the Bowens through a Westcott 43"/110cm white umbrella at my Sekonic flashmeter approximately 2 metres away, and then the same with the SB-800. I also attached the Nikon diffuser to the SB-800, as, although this reduces the output a little, it spreads the light nicely over the brolly (the flash covers 104 degrees, equivalent to a 14mm lens when the diffuser is attached). This enables the Speedlite to give a similar quality of light as the Bowens in this setup. Both flashes were set to full power.

As expected the Bowens beat the Speedlite by some margin, showing f/11, 2 stops more powerful than the Speedlite at f/5.6. So, still usable for individual portraits, especially as in practice the light could be positioned a lot closer to the subject. Of course using a second SB-800 firing through the same brolly would narrow this gap down to about 1 stop, but I'd probably need a third SB-800 to act as a fill light.

Why the SB-800, why not a more modern unit? Well, hardly used one's can be picked up easily for around £200-£220, which is about £120 less than a SB-900 or SB-910. Although it has a clunky interface compared to the more modern units, it is still the joint most powerful unit tested at and you can also pick up matching SD-8a battery packs for around £60.

Word of caution: if you're thinking of using some old studio lights with your modern DSLR, check carefully that the trigger voltage is not going to fry your camera. Or, do what I do and use a radio trigger so there is no electrical connection at all between flash and camera.

Nikon on a roll?

Nikon's latest DSLR offerings are fascinating, as they have brought the highest resolution to the DSLR market at a very attractive price, the D800 sporting 36mp for less than half the price of their 24mp flagship, the D3x.

For the first time they are also offering the camera in 2 versions, the D800E has the anti-aliasing filter removed, promising even greater sharpness at the risk of moire when shooting subjects with regular repeating patterns.

So, as the owner of a D3x and D7000, will I be getting a D800? Quite possibly, as the idea of trading my current cameras for 2 D800E's at first seems attractive. Having 2 identical cameras using the same batteries, and only losing out a little in DX resolution (15 vs 16mp for the D7000). I use DX with shift lenses a bit so this would be important to me.

But there are downsides: file sizes. Whilst my current workstation (64 bit, 2 dual-core 3GHz Xeon processors, 12GB of quad-channel RAM and solid state disk for OS and applications) is well up to scratch, even this slows noticeably with stitched images from my current cameras (32-108mp equivalents).

However, at the other end of the price scale, the forthcoming D3200 is an intriguing proposition to. From my perspective there's quite a lot not to like: RAW is only 12 bit and compressed; not 100% viewfinder; no autofocus with non AF-S lenses and clunky operation with AI lenses.

But, at the price, the D3200 seems like a great option for lugging up mountains and composing easy 48mp panoramics with a shift lens (using Liveview for the 100% view). Of course we'll just have to see how usable the PC-E lenses are on this compact body, if at all! That compact 'consumer' body saves almost 300g over the D7000, but no doubt the build will be lighter to.

Also the D3200 plus 50mm & 35mm f/1.8 AF-S, plus a Voigtlander 20mm would form a very compact outfit. Even substituting the 50 for the new 85 mm AF-S still keeps it small. But why are Nikon still not offering a compact wideangle prime for DX? Personally I would rather have seen this than the largely irrelevant 40mm DX macro. The Voigtlander is the only prime wide option that works with the exposure system but is manual focus, not that wide and comparatively expensive. I'd would love to see a prime 14mm f/4 AF-S DX (VR not required!) lens at a reasonable price (sub-£300?) and around 250-300g, and I'm sure a lot of other people would to.

I don't normally make predictions, but anyone can see the D3200 should sell extremely well, because of that headline-grabbing resolution. Unfortunately I can also foresee a lot of moaning on Internet fora, as I don't believe the 18-55mm kit lens will be up to the job, unless stopped down, and shot discipline at these resolutions needs to be very good.

There's some D3200 samples on DPReview here. The one of the glass house shows particularly good details.

Serious about Tripods

Thom Hogan is a wise man, and he's never wiser than when he writes his 'Tripod 101'.

Bottom line - if you're going to buy a tripod, don't skimp on the budget, as over time you'll end up spending more. Here's what I use:

Tripod 1 - the sturdy option

When I'm not walking too far or I am using a long lens and stability is more important than portability, I use a Gitzo 5-series tripod. This is an expensive but superb piece of kit, rated to a 25 kilo load, but I've seen a man that was at least 3.5 times that swing from one at Focus On Imaging (he worked for Gitzo). It's not that heavy (2.7 kilo) given it's strength but you wouldn't want to carry it all day!

On top I'll use a Manfrotto 410 geared head with a Hejnar Arca Swiss clamp (see my earlier post), or, for long lenses, the exceedingly simple but effective Manfrotto MN393 'gimbal' head.

The only thing I can find to criticise on the Gitzo is the way the top plate is attached - I think the design here is flawed and I fret that the plate could get wrenched out, sending my camera and expensive telephoto lens tumbling to its death! So, as I'm a little paranoid about this, I also use a Naturescapes Safety Plate which prevents this risk.

I've also wrapped the upper leg sections in Jack Pyke camouflage tape, not just to break up the shape, but also this makes the carbon fibre slightly nicer to handle, especially in cold weather.

Tripod 2 - the carry-all-day option

I have an old Manfrotto Carbon One 441 (3-section legs), with a short centre column and a small FLM ballhead with a Kirk Arca Swiss QR plate. This is a superbly light (~1.1 kilo) setup that will rigidly support a consumer-sized DSLR and tilt/shift lens, making it ideal for forays into the mountains.

If pushed, then without the legs extended I would trust it with a D3 and 300mm f/2.8 on the Manfrotto 393 head, but this is at the upper limit of what it can handle, and would definately cause some flex if the legs were extended.

On hikes I remove the head and column, placing it in one rucksack side pocket, with the legs in the other. You barely know it's there.