The GoPro stock housing goes deep!

Question: How deep can you really take the GoPro camera underwater (the box says 60m)? The way this works, is that any piece of equipment is 'rated' to a particular pressure. In the case of the GoPro Hero 3 underwater case, it will be rated to 7 atmospheres, which works out to 60 metres in freshwater and around 58 metres in salt water.

This is similar to bridges: They'll have a sign saying "Maximum 3 tons" or similar. This doesn't mean that if you are driving a truck that weighs 3 tons, but a kitten sits in your passenger seat, that the bridge will collapse.

There will be variations in each individual casings, too. Some underwater cases will happily go to 80 metres, others might make it to 90 metres, but some might fail at 68 metres. So, in order to keep your equipment safe, stay above 60 metres

For most people, all of this is moot, however, as a GoPro really isn't the right equipment for dives that deep. I'm a Divemaster, and I've dived extensively, both with and without photographic equipment -- and I don't think I've ever taken a half-decent photo at depths deeper than 30 metres or so. The light doesn't penetrate that deep, for one thing, but 40 metres is actually the maximum depth you can safely dive on air (see Recreational diving) -- so if you want to go deeper than 40, you're looking at becoming a 'technical diver' (see Technical diving), which is a different kettle of fish altogether.

Realistically with a camera without additional lighting, like the GoPro Hero 3, you'll probably only get good footage at depths down to about six metres, and usable footage down to about 15.

However!

In the comments of this article (originally published in 2013), a series of divers started posting how deep they've taken the GoPro stock housings, and I was in for a surprise! Have a look at the comments below, but some of the data points are here:

1. Steve mentions he's taken his Hero3 Black to 106 meters (348 ft) in a stock case
2. Jørgen mentions he's had the GoPro on a ROV to 100 meters (330 ft) in a stock case
3. Damien says he's taken a GoPro into caves and mines and in open water to 69m (230 ft)

Please do keep the comments coming!

Pass me a C-47 - or how a clothes peg got its film-set name

I was flipping through a book on film-making when I stumbled over a box-out mentioning the C-47. Or a clothes peg. Wooden clothes pegs are much-used on film-sets, where they don't conduct heat so can't burn people or melt. They make perfect handles for hot barn doors and they hold gels in place without dribbling into a puddle on the floor. Not to mention their grip over scripts, straws, and cables. Sometimes simple soilutions are the best. It did set my mind a-thinking, however. How did the humble clothes peg come to be known as a C-47? After a little digging, I don't have a defnitive answer, but I do have some pleasing stories.

After a plane?

The C-47 was a plane used extensively throughout the Second World War for troop movements, medical evacuations, and reconnaissance, and afterwards when it played a crucial role in the Berlin Airlift. It was a versatile plane, which mirrored the versatility of the clothes peg. Servicemen returning from the front to film studios carried over the name.

From a storage bin?

Some film studio somewhere stored its clothes pegs in a bin designated C-47. The name has stuck.

Its requisition number

Clothes pegs were assigned the catalogue or military requisition number C-47. They became known by their catalogue number rather than their common-or-garden name. Which leads neatly into the accountancy theory...

For accounting purposes

When gaffers and key grips were submitting requisition forms or expenses claims to film studio executives, accountants, and tax officials, they had trouble doing so for a bundle of clothes pegs, no matter how vital their presence was on set. By changing the name to something far more significant sounding, for example the clothes pegs' catalogue number, nit-picking officials were none-the-wiser and the best boys', grips', and lighting crew's fingers remained unburned.

Finally...

It makes a great joke to ask the new boy or girl for a C-47 and they have absolutely no idea what one is. And I'm reliably informed that what I know as a clothes peg (or even just 'peg') here in the UK is known as a clothespin in the US. Not that I'll be using any today for their traditional purpose of hanging washing on a line: it's pouring down.

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Written with help from:

• Know your film jargon: The (questionable) true story of the C-47, from Scouting New York
• Pass the C-47s, from DeHavilland's Livejournal
• C-47 Skytrain Military Transport, from Boeing

Can I use this photo I found on the Internet?

(Or, the non-photographer's guide to image use) It's a truth universally acknowledged that articles, newsletters, blog posts, posters, and basically anything involving blocks of text can be improved upon by the addition of an image. When you're writing about the local cycling club's criterium or producing a short introduction to crochet and macrame, you'll probably want some pictures to illustrate events or to explain techniques alongside your race report or detailed how-to. Can you take a look at the site of a local photographer and use some of his images from the cycle race? Can you conduct a Google Image Search for 'crochet' and download some photos of great examples of people's work?

The short answer is always 'No'. Just because someone has posted an image on the Intergoogles, it doesn't mean that it is free for other people to use. You can't use the china in John Lewis' window display without paying for it first, and a photo on Flickr is just the same. Images belong to the people who create them—or in some circumstances, to their employers—so they get to decide how and when they can be used and what the appropriate fee for using them is. We put them on our websites or on photosharing sites because we're proud of our work and we like to display our capabilities, but it's not an open invitation to filch them.

There are a few exceptions to this rule, but until you know better, work under the assumption that every photographer keeps the tightest control over the use of all of her or his images. Being confronted by an angry photographer wielding an invoice for unauthorised image use is not a pleasant situation, so remember: You can't use other people's photos. Mmm'kay?

For completeness, what are these exceptions you talk of?

Some people are happy to licence their images under Creative Commons terms. Creative Commons licences aren't designed as an alternative to traditional copyright, but a complement. They're easy-to-use copyright licenses that allow you permission to use a photographer's images under terms decided by the photographer. One photographer might let you modify and use his images commercially, but another might say that her images must be attributed, cannot be used commercially, and aren't to be modified. However, not all photographers use Creative Commons terms (you'll see it close to the photo if they do) and if there's no evidence of a Creative Commons licence, assume that you can't use the image.

If you receive an image in a press release or it's made available to you from the press section of a website, this will be free to use in the context of the product or situation. For example, when Olympus releases a new camera, it will make a bundle of images illustrating it available to me. Provided that I'm writing about that camera, I'm free to use them in an article. The National Portrait Gallery will supply a selection of images from each of its exhibitions so that if you're reviewing it or publicising one, you have photos to illustrate the article. But, you can only use those photos in relation to the relevant exhibition and they must be attributed under the terms set out by the NPG.

Some news agencies, for example AFP, are happy for you to use their photographers' images non-commercially and for personal use provided that you credit the photographer and agency and link back to the site. But, some agencies aren't. And you wouldn't want to face the wrath of AP or Reuters. Again, unless you're absolutely certain, assume that an image isn't free to use.

But what if you see an image and want to use it? What should you do?

Get in touch with the photographer! Most of us make it easy to send an email: do just that. We don't bite. Mostly. Tell us who you are, why and how you'd like to use a photograph that we've taken, and ask if you can come to an arrangement. The worst that we can say is 'No'.

That's not so hard, is it?

Q&A: What's the best compact camera with an optical or electronic viewfinder?

Personally, I have a bit of a love relationship with the Canon S-series of cameras. Yes, they don't have an optical or EVF viewfinder, but think about it this way: In designing these cameras, Canon decided to create the highest-end compact cameras they could, and there was no way that they were going to stick a poor screen on there. Even in bright screen, my S95 (and, subsequently the S100 and S110) work fantastically well, regardless of situation: I've used mine extensively both under and above water (see www.flickr.com/search/?w=83688756@N00&q=Canon+S95 for a rather broad sample), and I've never missed the viewfinder even once.

The other benefit of no viewfinders is that the screens can be far, far bigger, which has its own benefits.

TL;DR: Don't ignore cameras without viewfinders, LCD tech has gotten very far in the past few years.

Question via Quora.

Q&A: What is the ideal image spec that can be used for web and print?

The key thing to keep in mind is resolution. An image online that covers the entire width of the Quora page would be less than 1000 pixels wide. If that photo is as tall as it is wide, it's a 1 megapixel photo (1,000 x 1,000 pixels) If you take that photo and print it in high quality (300 dots per inch), it would be quite small (8.4 x 8.4 cm / 3 x 3 inches). So, if you are looking to buy / commission / create photographs that work both in print and on screen, then worry about print resolutions, not about the resolution on screen.

The second thing you need to worry about, is sharpening the image for its target output medium. Glossy magazines need the photos sharpened differently than if you want to show it on screen, or print it on newsprint. Cambridge in Colour has a great Guide to Image Sharpening.

Question via Quora