Chroma key & a free action

Have a look at this image, can you see the join? Click the image to enlarge it, if it helps. It’s made using a system called chroma key, which you may know as blue screen or green screen. You’ve seen chroma key at work before. It’s used widely on TV shows, in news interviews and weather reports, and all the time in the movies from the biggest sci-fi blockbusters right down to the tiny home spun amateur flicks.

I’ll put the original image at the end of the post.

If you want to try this yourself all you'll need is a blue or green background and either a lot of hours in Photoshop or download my free chroma key action.

To be honest you probably will need more then this action. Getting a good extraction is as much about getting a good shot in camera as it is about Photoshop skills. Hair is always a problem and if it’s long blond hair it’s vital that the original photograph is perfectly lit and correctly exposed. My number one chroma key tip is… always get the model to wear a hat. OK, that’s a bit tongue in cheek but there is a grain of truth in there.

Getting back to Photoshop, I’ve tried many techniques to make a quick, clean extraction in Photoshop. I loved Photoshop’s Extract Filter, but sadly Adobe didn’t and removed in in Photoshop CS4. Photoshop CS5 has a vastly improved masking system for selecting hair, which looks very promising, although I’ve yet to explore it in detail.

I’ve also used 3rd party Photoshop plug ins for chroma key and after trying quite a few demo version I settled on Primatte from Digital Anarchy as the most powerful and straight forward tool I could find.

The trouble was which ever system I used to cut out the blue or green background it always took time, particularly if I needed to work on a whole batch of images. To speed things along a little, I made an action which does a pretty good job of removing either blue screen or green screen from an image. It’s far from perfect but it gives a very quick and dirty way of see how the cut out will look.

The action is roughly based on a Dave Cross & Layers Magazine technique. Read the full article here

Favourite Lens - Quick Shot Answer

Name:: Tim Elliott

Question:: On your 15 minute challenges, what lens are you generally using please?

Answer: There are two main lenses I use in the 15 minute challenges. The first is my Canon 24-105L which and the second is a Canon 50mm f1.8.

So why use the 24-105? Well it’s easily the most used lens I own. Not only does it produce amazingly crisp images it also covers the kind focal lengths I need to use in every day life. For those two reasons it pretty much lives on my camera, so when the mood strikes to record a 15 minute photo challenge it’s often the only lens for the job I have on me.

You’re probably asking yourself, if Gavin loves the 24-105 lens so much why does he sometimes use the 50mm? It’s a fair question and deserves an honest answer.

Pretty much every camera manufacturer makes a 50mm lens and on the whole they’re one of the cheaper lenses you can buy. So when I conceived the idea for the 15 minute photo challenge I wanted to use a lens that was accessible to all and the 50mm f1.8 was it.

The other big advantage of the 50mm f1.8 is the fast maximum aperture. Shooting wide open at f1.8 allows me to get some very creative images with tiny depth of field like this image from my very first 15 minute photo challenge.

Battery chargers – Quick Shot Answer

Name:: Sats

Question:: I have Nikon D90 and SB-600. Please advise what kind of battery recharger I should use.

Answer:: Back in the “old days” when I shot film I can remember when I could go for a year or more before replacing the batteries in my camera. Today I rotate 4 batteries in my camera and countless AA batteries in my flash gun.

Sats, you don’t say what batteries you want to recharge but if it’s the big battery in my camera I’ve always used to recharger that came with the camera and I'm happy to continue with that.

The AA batteries that I use in my speedlites is another story. There's a wide choice of rechargers on the market. I’ve used several brands over the years but my current favourite is the GP PowerBank V800C. Sadly this model seems to be discontinued but here's a link to GP's website

The killer feature for an impatient person like me is its recharge speed. Four 2700mAh AA batteries will go from flat to charged in around 30 minutes. Of course that kind of recharging speed comes at a price and I’m not talking about how much the recharger cost.

The batteries get really, really hot during recharge even with the PowerBanks built in cooling fan. Putting hot batteries in the speedlite seems like a bad idea to me so I always let cool before use. I also find the rapid recharge causes the batteries fail faster then then I’d expect on a slower recharge. A failed battery will result in the PowerBank to flash red and stop charging.

Fortunatly AA’s are cheap to replace and represent amazing value compared to their non-rechargeable counter parts.

The making of a strobist image

Today was a good photography day. I was able to get out of the studio and into the real world, which turned out to be a dark, scary underpass where I photographed a right pair of dodgy looking characters.

Fortunately I know these two guys pretty well and have photographed them several times before. They are iF-e and GManHatton, a couple of Grime artists (a type of Rap music check out their website) from Crawley and despite appearances they’re both amazingly polite and great fun to work with.

They're about to release their second joint album and booked me to do the press / promo shots and the CD cover art. So after arranging to meet them in a Tesco car park we headed to a local underpass which I checked out a few days earlier.

The whole shoot was lit with a single speedlite (Canon 580EXII) as I wanted to perfect my strobist (off camera flash) skills. As soon as I saw the images on the cameras LCD I knew this was going to be a great shoot.

This kind of portrait lives and dies on perfect lighting control and getting it right is a three step process.

Step one: Unless you want your subjects to be against a jet black background you’ll want to mix the ambient light with flash. To achieve this you’ll need to work out what the ambient exposure actually is. IMPORTANT: The camera’s shutter speed must be lower then its flash sync speed (e.g. 1/250th sec in my case). This shot shows the effect I was after, a splash of light and colour in the background. The exposure was 1/40th sec at f11.


Step two: Now I need to setup the speedlite which I always use in full manual rather then TTL. I started with a flash of ½ power and took a test shot. A quick glace at the camera’s LCD showed the flash was a bit to strong so I dropped the flash to ¼ power. A flash meter could be used to skip this step.




Step three: With the flash set and the exposure locked in we’re rolling. Now I can move around and take different shots without needing to reset the exposure. I can even reposition the flash or change the pose and exposure will remain unchanged, as long as the flash to subject distance doesn’t change.


And here’s the final shop after a bit of Lightroom adjustment.
To give you an idea of how fast and free this technique is, here’s a wide shot. Photography by Sam HoeyFinally here’s a few of my favourite images from the shoot

One day workshop - Sunday 8th August

What are you doing on Sunday 8th August 2010? If you’re at a loose end and want to improve your photography & Photoshop skills, read on or skip straight to the booking page.

You’ve probably seen one of my 15 minute photo challenges so you’ll already have a pretty good idea of what I’m going to cover in my upcoming workshop. This isn’t going to be a day sitting in front of screen listening to me endless talking about myself and it’s not a day where I set up a shot and everyone gets exactly the same image. No, this is a workshop where you’ll learn by doing as well as watching.

The location

I’ve been very lucky enough to book Highley Manor in West Sussex for the day. We’ll have the entire place all to ourselves and I’ve managed to get permission to shoot images anywhere in the gardens and even inside the house.

There are just 15 places on the workshop, some of which have already gone so it’s first come first served on the rest.

I’m really excited about being able to shoot the interior of the Manor house. It has some amazing beautiful rooms which should yield some pretty unique images. There are also some unusual objects like this suit of armour behind the reception desk.

What to expect
The day is split up into a series of challenges. I’ll show you a camera technique, explain when and why to use it and we’ll all go out and put theory into practice. We’ll then spend some time reviewing the results and applying some of my Photoshop tricks.

By the end of the day you’ll be seeing interesting images all around you and have the skills to get the best images in camera and an understanding of some simple Photoshop techniques for getting the best out of them.

I’m a beginner, should I come?
The workshop is aimed at beginners/intermediate photographers. What does that mean?

To get the most out of the day you’ll need a basic knowledge of how to control your camera’s settings including how to change the ISO, how to shoot in RAW and most importantly, how to put your camera in Aperture Priority Mode. If you can do that then you’re good to go.

What equipment do I need?
A digital SLR camera is all that’s required. This isn’t a gear competition, bring everything you’ve got, but don’t buy anything just for the day. One of the themes for the day is learn your current equipment before buying more.

The only other essential equipment is a tripod. We’ll be shooting inside the manor at some point in the day and for that a tripod is a must.

Where are we going?
Highly manor is 5 minutes from the M23 (junction 10A) and about 15 minutes from Gatwick Airport so it’s very accessible. We have a maximum number of 15 places available on a first come first served basis. Bookings must be made in advance.

Will there be course notes?
Everyone attending the workshop will receive a free limited edition 15 minute photo challenge DVD. It was recorded at Highley Manor and will feature an extended 15 minute challenge with lots of unseen footage plus all the Photoshop tips and tricks I used to achieve the final results.

And before you ask, no you can’t just buy the DVD you’ll need to attend the workshop.


For more details or to book your place follow this link.

New online portfolio

Over the past few weeks I’ve been burning the midnight oil redesigning and rebranding the photography side of my business. The first site obvious change is a all new portfolio website which is now online.

As with any new website, it still needs a bit of polishing, but I’d like you to have a look and let me know what you think so far. Either click the image or here’s the link http://www.gavinphoto.co.uk/

So what’s the rebranding? Well after years of photographing kids, families and weddings it’s time for a new challenge. I’ve been fortunate enough to photograph some great unsigned bands and aspiring models over the past few months and that’s an area I’m keen to explore further… Watch this space.

How to photograph fireworks

My Quick Shots inbox has had a sudden flood of questions overnight regarding photographing fireworks. Here in the UK fireworks only come out at the beginning of November as we celebrate Bonfire Night or for New Years Eve of course.

But fireworks are part of celebrations all over the world and at different times of the year. This Photo was taken in Italy during Ferragosto (Assumption Day)which happens on August 15th.

So why the question today? Well today is 4th July, independence day in the USA. So, here’s my firework photography advice.

1) You’re going to need to get your camera on a tripod as the exposures will be long, far longer then you can do hand held.

2) Switch the camera to manual mode (M on your camera) and enter an aperture of f8 and a shutter speed of 2 seconds.

3) Point your camera to where the fireworks will be and wait.

4) As the fireworks go off take a shot and review the result.
If the sky is too bright use a smaller aperture (f11, f16 etc)
If the firework trails are too small use a longer shutter speed.

Extra tips
A cable release is very hand for this work. It stops you touching and therefore moving the camera which can cause blurred images. If your camera is having trouble focusing switch for manual focus and set it to infinity. Finally, don't use flash.