Sunday, May 23, 2010

First photo walk

This weekend I had the chance to go out for a short walk around sunset, down to the river near my house.  The light was nice despite it being winter and the sun weak.  Stupidly, despite the failing light, I didn't think to take my tripod, and so my opportunities were limited at the start, and grew more so as the walk went on and the sun went down.

At the pond in the park, I got around to the side away from the setting sun, and took some shots of the ducks.  The sky was quite brightly reflected, and I was after a silhouette type of shot that retained some detail of the ducks.  This one worked out quite well, though I would have liked just a little more detail visible on its neck and head.  It's also very 'blue' and would benefit from some Photoshopping to warm it up a bit.

The river itself is in a steep gulley, and looking across to the opposite bank, the trees (already autumnal) were catching the last rays of sunshine, and I noticed this house hidden among them on top of the hill, and thought that with appropriate cropping it would make a nice image. 

I normally like to shoot at 100 ISO for maximum clarity, but for this one, I had to go to 400 ISO to get a decent shutter speed I could still handhold. 

(Today's lesson)  The rule of thumb I learned back in the good old days of film was the slowest handheld shutter speed should be better than 1/focal length - so if you are shooting with a 200mm lens, your speed needs to be 1/200 or quicker, while a 50mm lens can be handheld at 1/50.  Of course, these days, a lot of lenses, especially the longer ones, have built in Vibration Reduction (Nikon) or Image Stabilisation (Canon) systems that may give you an extra few stops of handheld stability, and sensor sizes may have an impact too (e.g. on my camera, the 200mm behaves like the equivalent of a lens nearer 300mm). 

This was the last handheld shot of the day - I tried a few more with the camera balanced on a rock, but with a 60' drop from where I was (very similar to what you can see on the other side), I didn't feel too happy about my precarious perch, on a lonely path in the fading light, and decided to call it a day.

So what did I learn?  My lenses are only standard kit lenses, and don't have the huge light gathering apertures of the $1000+ lenses that the pros use, so if the light is fading - take the tripod!

Thursday, May 6, 2010

Lesson 01 - The basic principles of taking a photograph.

Well, I've posted a few pictures and chat, so figured it's about time to start sharing some knowledge. I don't pretend to know everything about photography, nor can I take stunning photos (at least not intentionally - all my best photos were accidents :D ). However, I do have a knack of being able to talk technical in non-technical language, which is often helpful to absolute beginners. And so, armed with this skill, and a little knowledge, I hope to write a few articles from time to time, that will bring some enlightenment to somebody out there who has got a camera, takes snaps, but wants to do more.

I know this is a long-ish post, but it sets the groundwork, and hopefully isn't too demanding to read.
I'll try and keep future lessons shorter - I promise.

The basics
There are just 2 things you need to create a photograph - light, and something that is sensitive to light, that will record your image.  That sensitive something used to be film but in today's digital age, is now frequently a little bit of electronic wizardry called the 'sensor'.  I haven't used a film camera in years, and the chances are that any new photographer these days will have a digital camera of some type, so I won't be talking about film too much.

So, you have your sunshine all around you, and the sensor in your hand, and... ah ok, the sensor needs to be attached to some electronics and a screen or monitor so we can see the image... (short break while I get out my soldering iron) 

Hmm, it's very 'white'... there's far too much light around - we need a way of controlling the light that gets to the sensor. So we'll start by enclosing the sensor inside a box which is nice and dark (perhaps we could call this a... camera - that sounds good...) Next, we'll make a hole at the front to let the light in, and we'll just open that hole very quickly and shut it again. Now we're starting to see some light and dark patches on the sensor. If we open the hole for a longer time, or make the hole bigger, more light gets in, and the picture gets whiter again. Open the hole for a shorter time, or make the hole smaller, and less light gets in, and the picture gets darker.

So - this is the first valuable lesson - we have to find the right balance of the time we leave the hole open, and how big it is, in order to let just the right amount of light into the camera.
This is probably the single most important technical concept you need to grasp - and it's not really that complicated, is it?

Let's use some proper names for these things...
The hole that the light comes through is called the iris. It is a set of interlocking blades of metal that can be adjusted to make the hole bigger or smaller. The actual size of the hole is called the aperture. Aperture is measured in f-numbers, which confusingly get bigger as the hole gets smaller - so f/1.4 is a big hole letting in loads of light and f/22 is really teeny tiny.

Covering the sensor (and keeping it nice and dark) is the shutter. Think of it as a set of curtains that can be opened and closed very quickly (as quickly as 1/4000th of a second!). The time that the shutter remains open is called the shutter speed.  Light is constantly coming into the camera though the iris, so the shutter controls how long the light actually gets all the way through to the sensor.

NB - Some cheaper digital cameras achieve the same thing electronically, rather than there being a physical shutter mechanism across the front of the sensor.  While this might seem like a simpler solution, there is a problem in that the sensor is always active, and that a camera that has no shutter must first clear and reset the sensor before 'taking' the picture.  In a camera with a mechanical shutter, this can be done while the sensor is in darkness, prior to taking the photo.  So a camera with a mechanical shutter will actually react a bit quicker than one without.

So, by adjusting the aperture and shutter speed, we can find a nice balance to let the right amount of light in, but hang on, it's all blurred. That's what the lens is for... (by this, I mean the actual piece(s) of glass, as opposed to the black cylindrical thing you screw on the front of an SLR camera).  The lens focuses the light that passes through the iris, so that when it arrives at the sensor, it is all nicely ordered and forms a recognisable image. Without the lens, the light is bouncing around all over the place and makes no sense - the lens helps straighten things out and aim it in the right direction. 

There is one more variable in the aperture/shutter speed equasion, that helps control the amount of light used for your photo, and that is the sensitivity of the sensor. Imagine the sensitive tips of your fingers, compared with the thick skin on the heel of your foot. Your fingers will feel the tiniest needle prick, while your heel will take a lot more punishment. Wouldn't it be nice if you could change the sensitivity of your fingers, to make them more like your heel, next time you wanted to prune a thorny bush? Well, the same principle applies to the sensor in the camera. If you have your lens wide open to the largest aperture, and the shutter open for 30 seconds, and STILL there is not enough light (yes - it CAN happen), then you can make the sensor more sensitive so it will react to the available light quicker.

Be careful here though - as you make the sensor more sensitive, it is also prone to accidentally registering light, and creating grainy spotty images that don't look so nice. In the digital world, this is called 'noise' (in the world of film and negatives, it is called 'grain' - it's the same concept but having a chemical rather than electronic cause). The sensitivity of the sensor is measured using the ISO scale. ISO 100 or 200 are usual for normal photography, but the values keep doubling as you make the sensor more sensitive (and more susceptible to noise), e.g. 400, 800, 1600 (now you're into risky territory), and some cameras go even higher.  100 to 1600 are the most common range of ISO settings on everyday cameras, but film can be rated better than 100 (i.e. a lower number meaning higher quality) down to ISO 64, though I've not seen the equivalent on a digital camera (I'm happy to be shown otherwise though).

Well - that's probably more than enough for the moment. I don't want to scare you off. I'll take a break before giving you lesson 2 (while I think what it should be about).

Now - back to the photography.

Monday, May 3, 2010

Cheap Filters Experiment

Today, I took delivery of a couple of UV filters, plus a Circular Polarising filter, plus a remote shutter release that I purchased on ebay for around $18 (AUD) in total.  At just a little over $4 each, the UV filters are cheaper than a Nikon lens cap, so if their optical quality is no good, I can use them as lens caps instead.  My daughter's Hoya equivalents were around $30 each 2 years ago. 

and yes - this photo was taken with one of the UV filters attached.

The Circular Polariser is a bit of a gamble, but at $4.80 compared with around $60 for the cheapest Hoya I could see, I figure it is worth a try (I can spare $5 by missing my morning coffee for a couple of days, but it will take me a while to get a 'spare' $60 together)  This way I have something I can play with, even if it isn't perfect, until I can afford/justify something optically better.

As for the remote - it's not much more than a battery and an infra-red LED - I can't really understand how Nikon can justify asking $40 for it in the first place - so I have no problem buying a cheap copy. Having said that, I had a scary moment when I first tried it out... I set the camera to react to the remote, stood back and pressed the button, and great news - it took a photo. I went to look at it, and found the camera had died... uh oh - what have I done!!! :-o Then I realised - the battery was low, and I guess that one more shot with the flash was enough to just tip it over the edge. I've now recharged the battery, and taken a few more shots with the remote (just to make sure...)

Since my daughter has Hoya UV and CPL filters, and I now have chinese cheapo versions from ebay, it will be an interesting test to see if there is any notable difference between them.  We'll run some comparison experiments and I'll get back to you with the results.

(Tuesday - First Impressions...)
the two UV filters attached to my lenses without any problem, but the thread on the CPL filter is a little tricky to get lined up straight - I may leave the UV filters on, and put the CPL over the top - I'd rather bugger one of their threads, than the thread on the lens itself.

Pole Position...

To make up for the lack of a photo from this weekend - which I know will have bitterly disappointed my readers (if I have any...), I thought I'd post this one instead.  It's a reminder that a photo opportunity may turn up at any time, and if you don't have your camera with you... it's gone.

Here, I was just waiting to cross the street, when the silver car pulled up at the stop line.  I actually was hoping to get a close-up of the wheel and the brightly coloured brake caliper, but just as I was lining up the shot (in the gaps between cars going in the opposite direction), the purple car came and obliterated half the shot.  I re-aligned the shot based on what I could still see, and came up with this composition, which I was actually quite pleased with as an impromptu 'missed chance'.  I ought to have a go at removing the pair of legs across the street, and giving the car a bit of a polish with Photoshop... (I wish I could polish MY car with Photoshop!)

Ghosts, Birthdays, and Wii-ing it up.

My camera came out of its case several times over the weekend, but I have no pictures of note to post - let me tell you why...

Outing 1 - Friday Night - Ghost tour in Picton.
We went on one of these several months ago, and I took along my P&S...  Took loads of photos that night in the hope of seeing something inexplicable in one of them, but though there were plenty of 'orbs' according to our tour guide, I personally think they were just out of focus insects, raindrops, and dust being caught in the flash.  On Friday, I thought I'd take the D3000 and get 'better' pictures - how wrong I was.  The first problem, was that in auto-focus, it was too dark for the camera to focus, and so the shutter wouldn't release.  Score 1 to the P&S.  When I changed it to manual-focus, I couldn't see enough to focus it either, so although it took pictures, everything was pretty much out of focus - not just the 'orbs'.  Score another 1 to the P&S. 
Lesson learned?  Ghost-hunting is better with a fully auto P&S that will try to take a picture no matter what the conditions, but ghosts don't like their photos being taken anyway.

Outing 2 - Saturday - My wife's birthday party.
We opened Karen's pressies very early in the morning, due to my son's need to leave for work at 7.30am.  Having all just rolled out of bed, it didn't seem politically correct to take photos of everyone's "morning glory", so I waited until her birthday tea in the evening.  The lights went down, cake candles were lit, and 'happy birthday' was being sung while I was powering up the camera, etc., and then before I know it, she's blowing out the candles (or rather our enthusiastic niece and nephew were) - so I aimed the camera, pressed the button, and the shutter opens... and then 3 seconds later, closes again :-o  Shot missed - D'oh!
Lesson learned?  Reset all the camera settings after each shoot (especially after a night-shoot) so that it is ready to just grab and click in a jiffy.

Outing 3 - Saturday night - Wii-ing hard
After getting home again, we decided to give Karen's new Wii a try-out.  We'd had a few drinks (except me as nominated driver/photographer who has to stay sober) and already loosened up a bit with some Wii-karaoke, so the Wii dance game was booted up, and there we were - girls vs. boys, strutting our stuff in front of the TV (with all the curtains closed!).  I got some great pictures of everyone having a thoroughly good time, but I know they'd never speak to me again if the photos went public - so I'm not going to do a 'facebook' on them...
Lesson learned?  Put the camera down, have a drink or two, and party with everyone else.