iPhones. They're like Marmite. You either love them, or you hate them. (I'm ignoring the faux-haters who are really just jealous that they don't have iPhones.) With over 3million iPhone 4 sold in 3 weeks though, there's no doubting there are a lot of 'lovers' out there.

Thing is, which ever side of the fence you're on, there is one thing you can't deny - there are literally thousands of apps and while most of them are complete pants, some are very useful. So this post is not about EOS per-se, but apps for the iPhone that I think all photographers should consider.

By this, I don't mean the plethora of apps to help with taking pictures on the iPhone, but instead the apps that help you improve your pictures taken with your SLR. If you don't have an iPhone or are not an iPhone lover, don't stop reading. Perhaps you're an Android or Windows Mobile user. There are apps for you too and this may give you an idea of what to go and looks for.

Now, as with everything, there is usually more than one app to do a job, so these are simply my picks - apps I've found that I like and use regularly. Of course, some of them are not as cheap as you'd expect and there may be free apps that mostly do what you went. However, I feel you get what you pay for and having used free apps and their pads counterparts, I more often than not look at the paid apps now - the free apps left a me a little underwhelmed. So, on with the apps.

Helios - £17.99
Photography is all about capturing light. So it helps to know where and when the sun will make an appearance. Helios is a sun position calculator - it tells you the sunrise and sunset times, along with twilight times, but more than that it can overlay this on a google map view showing exactly where the sun will be at any given time on any given day. OK, so it doesn't account for weather, but then at least knowing where it should be is useful. And with the map view (which can be overlaid with the google satellite view) you can see if there is anything in the way. Next up is the clinometer view. Want to know what time the sun will drop below a certain level - maybe a building? Simply point the clinometer at the top of the building and it will tell you what time the sun will pass that elevation and at what angle. It even tells you the shadow ratio - how long the shadows will be. If you know how high the object is, you can then use the shadow ration to calculate the length of the shadows. With all this, the app is also location aware - you can turn on the compass in the app and the views re-orientate so the sun is shown where it is in relation to your current position. For planning shoots, it's a great app. If you find it a bit expensive, then have a look at The Photographer's Ephemeris. I've waxed lyrical about this before - when it was an app for Windows and Mac. I said at the time I'd buy it if it was an iPhone app and duly I have. It's cheaper than Helios (quite considerably) and misses some of the functions but for seeing the sun position over a google map view and knowing where the sun is, it works well.

Marine Tides Planner 10 - £2.99
Interested in shooting seascapes or shooting near the seaside? If so, it will prove useful to know the tide times. While this app is aimed at sailors and has more info than a photographer needs, for finding out high and low tide times it's very useful. Now you can work out if sunrise and tides match up to achieve that shot you've been planning for ages.

Darkness - £1.19
A bit like Helios without the map view and compass stuff, it tells you sunrise, sunset, twilight, moon phase and the azimuth at which sunrise/set etc happen. Combined with the iPhone compass, this gives you most of what you might need.

PhotoCalc - £1.79
This is a veritable swiss-army knife of an app. A real gem that does some many useful things. Mostly used by me as a depth-of-field calculator, it allows you to work out how much DofF you'll have in a shot, or more interestingly, both for landscapes and video, what the hyperfocal distance is for your given camera at any focal length and aperture setting. There is also a flash power calculator for when you decide to skip E-TTL and work out your flash settings manually, As well as a sunrise/sunset time for your current location. For those still shooting film, there is also an exposure reciprocity calculator and it's all wrapped with a pretty good glossary, an explanation of commonly used filters, a description of the Ansel Adam's zone system and some info about different types of film (not that useful these days!) and the sunny 16 rule for exposure - again, less useful with digital cameras.

Easy Release - £5.99
If you photograph models, then this is an app you will not want to be without. Called Easy Release, it does what it says on the tin - it make obtaining model release or property release easy! There are simple templates included but you can add your own release forms if you wish and it provides a way for your model to input their info and sign, using the touch screen. With that all done, you can email either a JPEG or PDF directly from the iphone to both yourself and the model so you're both happy and can get on with the shoot. It saves carrying and filing reams of paper and is a good ice-breaker at a shoot when the model gets to try and sign using her finger! (It does take some practice!)

Waypoints - £1.79
Sometimes where you're out an about you come across a location that you think might be interesting to revisit. Waypoints is a simple app that marks your current GPS co-ordinates and allows you to add some notes to it. For example, you may be walking through a beech wood and think it would be a good place to return in the autumn for fungi - simply drop a waypoint and store the notes and off you go. When it comes to re-finding your waypoint, you can have it displayed directly into the google maps on the phone so you can see where it is and how to get back there.

Birds of Britain and Ireland (Pro Edition) - £12.49
This is clearly only of use to those interested in bird photography, but if you need help ID'ing birds, this is very good. It provides descriptions (from the Concise Birds of Western Paleoarctic), distribution, illustrations (adults, young, nests, eggs etc as well as various different calls. If you have an idea what you might be looking at or listening too, it really does help you nail down exactly what it is. It includes pretty much anything you're likely to come across in the British Isles as well as some migrants that may make their way over on occasion.

Battery Doctor Pro - Currently on sale 59p
Not a photo app at all, but one that all iPhones should have. It's known that if you use apps, 3G and WiFi on your phone, the battery life will decrease rapidly. Keeping your battery in top condition helps extend the life and makes sure you don't run out of juice just when you need your phone (just like keeping your Lithium Ion batteries, like the LP-E6, in top condition by running them down to flat in the camera before recharging them). Certainly the life of my iPhone 4 battery is improved over the 3G I had before, but this app really does seem to make a difference. Now, I must confess I've not done any scientific testing, but in observations over the last coupled of weeks I've noted the times I've used Battery Doctor Pro the battery life has been better. Take a typical morning for me. I wake up, roll over, chat with the other half. She goes to the bathroom to get ready for work and I pick up the iPhone and check the weather for the day, read the news on the Guardian, have a run through the twitter posts and maybe grab a sneaky game of flick football. All in all, I'm on the phone using WiFi for about 20-30mins. If I haven't used Battery Doctor the night before, I can see the battery life drop several percent - say from 100% to 90%. However, having used the app the night before, it seems to only drop to around 95% - quite a good saving in my mind. So, what does the app do? Well, the idea is you keep the health of the battery high. This is achieved by using proper charge cycles. So, in this case I try and get the life down to under 20% before I go to bed. I then turn on the app and plug in the phone and over the course of the night it does a full charge to 100%, then a deep cycle charge and then a trickle charge. This ensures the battery has had a complete charge cycle and is working maximally.

I lied - there is one free app I find useful - Flashlight. Flashlight, like Torch for iPhone 4 and any number of other light apps gives you either a nice bright white screen (or any of a range of other colours) or lights the LED light on the back of the iPhone 4. The LED light is useful for finding keys or a keyhole, but the whole screen being white makes a great small, portable softbox light! It's not powerful and is only useful close up portraits, but it provides a nice light and may help you grab a shot you otherwise couldn't. 

So, a range of apps that far from being mere gimmicks actually help with your photography. Whether you think they'll help you is your choice, but for me, they are the first apps I put on my phone and ones I find myself using regularly. 

How about your apps? What do you consider essential for your phone? Or is there an app that doesn't exist that you'd like to see made?

Have you looked longingly at a Canon TC-80N3 and thought you’d love to have one but paying £130 is a bit much to swallow? Or have you looked at it and thought ‘if only I had an N3 connected camera rather than an E3 connected one!’ ? If either of these is you, then you really should take a look at Hahnel Giga T Pro.

Sounds like a mouthful, but it’s actually a pocket marvel. This is a bit of a red-letter day as usually you’ll hardly ever hear me recommend a 3rd party product over a Canon equivalent (not for any reason more than I hardly ever find 3rd party products doing as good a job as the Canon ones) but this is an exception. The Hahnel takes the TC-80N3 functions, puts them in a wireless package and does it for much less money. Bonus!

So what is it? Essentially the Giga T Pro consists of a transmitter and a receiver. The receiver has a mini-jack on the side and the whole thing comes with two different cables - one terminating in a N3 connector and one in an E3 connector. Yep, that’s right, all of you with EOS 300D, 350D, 400D, 450D, 500D, 550D and 1000D can now perform complete timelapse functions, not to mention get involved in really long (and accurately timed) Bulb exposures for astrophotography.

The functions included are: long exposure, interval timer, self timer and shot count. Combining one or more of these gives you a huge range of options for setting when, how often and for how long the shutter is tripped.

Even better, being wireless you can trigger the camera from a distance and avoid two issues - where to hang the TC-80N3 when shooting a really long exposure and making sure you don’t pull on the cable accidentally and jolt the camera.

The transmitter is where you make all the settings and to be honest, the manual is not the clearest and it’s not the most intuitive unit to set, but then again, neither is the TC-80N3.

The unit uses a 2.4GHz wireless connection and here it adds another trump over the TC-80N3 and the LC-5 - the range is up to 100m! Nope, you’re not limited to 80cm (like the TC-80N3 cable) nor to line of sight, like the LC-5 infra-red unit. And being wireless, you’re less likely to accidentally follow my favourite mistake.... having the TC-80N3 dangling from the camera when shooting with the tripod over water, only to notice the release merrily bobbing in the water.

And if you don’t need all the fancy functions, you can make use of the unit as a simple remote trigger (although there is a cheaper version without all the timelapse functions available).

Is it all hunky dory? Mostly yes, with one caveat - the connector to N3 connectors on a camera does not feature a locking latch like the Canon TC-80N3 (and other N3 connectors) do. This means it can slip out accidentally, which is somewhat annoying. Also, while having cables that plug in to adapt to different cameras is brilliant and useful, it also means another cable to carry around and lose.

Overall it feels well built (time will tell how much this counts for) but for now, if you’re in the market for a remote release or you want to upgrade your TC-80N3 (there, I said it!) there’s nothing better out there, that I know of, than the Hahnel Giga T Pro.

It's important to test yourself, to take yourself out of your comfort zone and shoot pictures of things you don’t often tackle. It’s how you keep yourself fresh and also how you learn new skills. With that in mind, I spent last Saturday at RIAT.  How many of you enjoy heading out to an airshow to capture some fast jets or the old war birds in flight? Judging by the number of people at RIAT with cameras, it’s quite a high percentage. And if you’ve not been to an airshow since you were a little child, I highly recommend it as a great day out. Take the camera, take a packed lunch, go with some friends and have a ball.

I’ve been to airshows in the past and taken pictures with some reasonable success, however this weekend I went to RIAT, the Royal International Air Tattoo at RAF Fairford and although I had access to a variety of cameras, I choose to take the EOS 7D. Certainly part of my thinking was that it is a lighter camera and with a slipped disc I wanted to minimise weight where possible, but the main reason was the focusing system. The EOS 7D features a very advanced AF system. While it may not be, in outright terms, as quick as an EOS-1D Mark IV, it has something the MkIV misses - Zone AF. I’ve talked a bit about the AF system on the EOS 7D before, but as a quick recap, there are five different modes you can use: Single Point AF, Spot AF, Auto Point Selection, AF point Expansion and Zone AF. Of these, for moving subjects Zone AF and AF point Expansion are the most interesting as they give you large focus areas to place over your subject to maximise your chance of getting it in focus.

For the most part, I spent the day using Zone AF. Now I’ve used Zone in the past and had mixed results. I’ve found with a contrasty background, the AF system can jump to that because there is no priority to the AF points used within the zone - they simply go where they think there is the most contrast. However, Saturday at RIAT was a lovely day - some cloud, some sun and some perfect clear blue skies. If you have a contrasty background, then switching to AF Point expansion gives you a more precise area to focus with and is less likely to grab the background, but still has a larger area than a single point for you to track fast moving subjects with. Zone AF basically gives you five focus zones to select from - each zone is made up of several AF points and they will focu

s where they find contrast. Simply placing a zone over your subject, in this case and airplane, gives you freedom of composition (with five zones it’s very quick to shift between them) as well as freedom within the zone. It makes for a very intuitive system that’s fast an accurate. There is one other reason the EOS 7D is so capable for airshows - 8fps shooting speed. Now I’m not one for shooting bursts, though I know some others are. Personally I find my best shots are the one off shots where I’ve picked a moment at the time rather than snatching a still from a sequence of 20. However, there are times when taking a 3 or 4 shot burst is useful at an airshow and gives you a higher chance of grabbing the picture. Having 8fps to play with means you’ll take those 3 or 4 shots in a shorted time so you have a more compact sequence in terms of picture elements within the scene. So, is the EOS 7D the best airshow camera out there? I think it might be up there with the best of them, in fact, next time I go to a show it will remain my camera of choice even if weight is no longer an issue!

All images © David Newton 2010. All rights reserved, no image may be copied or used without the copyright owner's permission. Please contact David Newton if you wish to use these images.