Tuesday, 16 November 2010

Orion Nebula - Astrophotography

It was Astrophotography that originally got me into photography.  Once you spend x amount on a DSLR you quickly find that only using it on clear dark nights (few and far between here in the UK) is not using it to its full potential.  However the shots that you do get when the nights are clear, tracking mount works as it should, alignment is spot on and the laptop doesnt shut down because of the freezing cold nights then the shots that you can get are quite literally out of this world.  

Orion Nebula, Canon 1000D attached to an C80ED
Above is a shot of the Orion Nebula and the Runnng Man near the top this was achieved by attaching the camera to a telescope (basically just acts as a really big lens) via an adapter.  Using the LiveView functionality of the camera attached to a laptop you can focus on a bright star and then set the camera to manual mode and for this shot I set the shutter speed to be 13 seconds long and I had the ISO at 800 which was the sweet spot for the camera good light sensitivity and low noise.  This shot was composed of 50 of these shots and then using some very clever software (DeepSkyStacker DSS) stacked on top of each other allowing the random noise to be evened out while enhancing very faint details.  Stacking allows the photographer to create photos that would normally require very long exposures and super accurate tracking to avoid blur.  Even if you could manage to take a very long exposure of say 60 seconds or greater you then have the problem of light pollution having a very large affect on the shot, unless you are lucky enough to shoot from a very dark location.

If you are interested in doing some basic astrophotography then even without a telescope you can get some pretty amazing photos of the night sky, by placing you camera on a tripod point towards the night sky, set the camera to manual mode.  Set the shutter speed to be around 10-15 seconds, aperture to as wide as you can (lowest f number) and a resonably high ISO 400-800 higher if you know how noisy the sensor is.  Once you are ready to take the photo either use a shutter release cable to  avoid camera shake or a little tip if you dont have one is to use the cameras 2 second timer.  You may need to tweak these settings but you should see that the amount of stars you capture is incredible you may even get the hints of a galaxy like M31 the Andromeda galaxy or the Milkyway band showing.  Try combing multiple shots using DSS mentioned above to get even more detail and play around with the curves in Gimp or Photoshop to enhance the detail further.

If this is something you are interested in the give me a shout and I will post some tutorials and details on this and other shots.

Thursday, 4 November 2010

In-camera black & white - What a waste.

There are a few reasons why people still resort to the in-camera black & white (b&w) mode, the two I hear the most is “ease of use” and the second “it allows you to be more creative in your shots” the second reason is because not all images make good b&w photos.  However my own personal thought is there is very little reason for someone with a decent digital camera to be using in-camera b&w mode.  The creative argument falls down when you can on most decent cameras shoot in photos in RAW, if you shoot in RAW and use the in-camera b&w the image you see on screen in b&w yet the RAW files will still contain all the colour information which would normally be lost if shoot as a jpeg.   This allows you to be selectively creative when shooting as it gives you an idea how the shot will look in b&w.

I have often wondered why some people will take photos in this mode when you get far more creative scope doing this post processing (pp).   When I suggest you convert to b&w in pp I don’t just mean using the “desaturate” or “greyscale” button in Photoshop or Gimp which is the same as turning on the b&w mode on your camera (from now on in this post I will refer to Gimp to perform a b&w conversion) .  By far the best way to create a b&w image is to go into the “channel mixer” menu in GIMP check  “preserve luminosity” and “monochrome” and now play around with the various sliders to get the look your after.  The obvious advantage of using the channels in this way to create a b&w image is the flexibility it gives you, and allows you to create b&w photos that look more like photos taken with b&w film and a professional photographer adding grain actually works really well with b&w images it gives them more texture and a film like quality.

As you can see from the photos above there are many different version of black and white and the above images would only be possible if you have the colour information to start with (so don’t just throw it away).  Another advantage of shooting in colour is the ability to convert to b&w and do some “selective colouring” what I mean by this is having a b&w photo yet have elements in colour (if you are interested in doing some selective colouring let me know and I will post a tutorial on the subject).

Tuesday, 2 November 2010

Improve your photos - "Rule of Thirds"

If you want to improve the composition in your photos then read this:

One of the most common rules in photography is “The Rule of Thirds” and an easy way to improve the composition of any photo is to follow this rule.  The idea behind this rule is to prevent the subject matter from being in the centre and landscapes to stop the horizon from dividing the photo in half.  Studies have shown the human eye naturally travels to the corners of an image away from the centre, artists for centuries have used this rule when painting.  

So how do you use the rule? 

If you check out the diagram above you can see that I have marked in green where the lines cross this is where you should place points of interest in the photo while lining the subject up with one of the lines.  So for example if taking a portrait photo you would want the eyes to be on or near green dots or in the case of person you would line the body up with on of the vertical lines while having the head/eyes fall on one of the intersections.  If you are taking a photo of a landscape you would have the horizon follow one of the horizontal lines which one is up to the photographer to decide which looks best.  

Here is an example:

Following this simple rule can improve pretty much any photo however as with all rules there can and are exceptions, but to be able to break these rules you must first master them.