"Duct tape is like The Force. It has a light side, a dark side, and it holds the universe together...."  Carl Zwanzig

No photographer's gadget bag is complete without duct (or Duck) tape. However, carrying those big rolls around can be quite heavy especially if you're a photographer who shoots in the field - wildlife, landscape, macro etc where you don't need a 10m roll of the stuff and where you do need to travel light. It's fine for those photographers confined to the studio or shooting high end commercial work with big lighting rigs, there a roll of duck tape is hardly noticed. For the rest of us, a metre or two is all you'll need, negating the requirements for a big roll.

But how can you carry it easily? Well, for those of you who remember film, I discovered about 8 years ago that a film canister is exactly the same width as a roll of duck tape. All you need to do is wrap 10 or 15 turns around the film canister and hey presto, instant gaffer tape on location.

The real beauty of this though, is that you can still use the film canister to hold other items - blue-tac, paper clips, drawing pins, plasters, antisceptic wipes... whatever you need. And better still, it's waterproof in there as well. In fact, whether you put duck tape on the outside of a film canister or not, it's worth carrying one with some little bits in it anyway - especially the plasters and antisceptic wipes...or maybe that's just me. Duck tape really does have a million and one uses, but no, I won't list them for you! Here's just a few things I've used it for.

* Sticking lens hoods onto lenses to stop them being knocked off
* Sticking flashguns to....well, just about anything
* Fixing broken kit
* Attaching light modifiers to flashguns
* Making random stuff

Spot AF eh? Sounds like a great idea doesn't it? You know, use a smaller area of the AF sensor for more precise focusing?

Yes, we like the sound of that. Trouble is, it's not the answer to all your prayers and it's certainly not the  best AF mode to use on the EOS 7D by default. In fact, use it and you'll probably find it's not as good as you thought - unless of course you use it wisely. And that means only in situations when it's appropriate. 

The reality is that spot AF is good in bright light on fairly static subjects when you want to focus 'through' obstacles, or when shooting portraits and you want precise focus on the eyes. In all other situations, it's a bad idea to use it - it is slower to track and harder to keep the point on the exact spot you want to focus on. More than that, in low light, it takes longer to focus as well due to the smaller area of the AF sensor being active and therefore less low light sensitivity. 

In short, use it with static subjects, in good light, or when shooting portraits. For all other situations, look elsewhere in the four other AF selection modes for focusing nirvana. 

There are similar restrictions with the other AF modes too, especially Zone AF and AF Point expansion. But I'll save those for future posts. For now I just wanted to get Spot AF off my chest as I've had several emails about it recently. 

So, you've got an EOS 5D Mark II, you have been shooting some movies and you like the idea of the EOS-1D Mark IV which has an instant filming button so you can press that and whatever mode you're in it will start filming?

Well, you can do it on the EOS 5D Mark II as well. Yes, the answer is indeed found in the Custom Functions. You know, those things that most of us never look at and hardly ever make use of? 

Well, the one you're looking for is a real cracker - Custom Function IV-3, and it's called "Assign SET button".

I'm willing to bet that if you take a look at this, it will be set to 0: Normal (disabled).

Try setting it to Option 6 - Record Movie (Live View).

With that done, head out of the menus and in whatever mode you happen to be in, press the SET button.  As long as Movie shooting is enabled in the Live View settings, (Live View Function settings > Stills + Movie > Any of the following three), pressing that SET button will pop up the mirror, put you in Live View mode and automatically start recording. 

If you're a photojournalist, or you just want to be able to react to a situation quickly, this will shave valuable time off accessing the movie shooting functions.Just be careful with it. It's easy to knock the SET button and find yourself in movie mode and filling card space without realising it.