Monday, March 29, 2010

How to Buy a Digital Camera - Part I

Perhaps I'm getting ahead of myself. Maybe you don't have a digital camera yet. While this is a rather huge topic, I'll try and distill it to its most basic points.

Price
Likely your first consideration. Most retail (i.e. not used) digital cameras will run somewhere between $100-$300 US/Canadian.

Much less than that and you'll likely run into problems. Very cheap cameras lose the pictures when you take the batteries out. They will be a very small and/or poor quality pictures even if they do save to a memory card. The least expensive won't have an LCD screen to review your snaps.

Sub $100 cameras aren't a bad starting camera for someone quite young - at least till their early teens. Expect it to be outgrown very soon, and more headaches when less money is spent.


Beware of stats. While they might be technically correct, they don't tell the quality of the components.

Below are 100% cropped shots of a new, cheap 9MP camera (top) and a old 6MP camera (used costs as much as the 9MP retail)

9MP

6MP

Megapixels really only measures the final size of the image. As you can see, a larger number here isn't automatically better. Any (quality) camera 6MP and up will print a passable 8x10.

While double the Megapixels is double the image size, it's still not as noticeable as one would expect.

In the image below, the 6MP is a 4:3 ratio Point and Shoot camera and the larger 12.2MP image represents a 4:6 ratio SLR camera.
Megapixel


If you are able to spend more than $300, there's also reason to be careful. If you are buying a point and shoot camera, you're in danger of being a victim of 'bleeding edge': Technology which is overpriced and not yet perfected. You might want to consider an SLR camera (more on that later).

Size
In terms of dimensions, there is a huge spectrum: between small pocket-sized cameras to large SLR cameras.

While the practical benefits of a small camera are fairly obvious, there's a few things to keep in mind. First, you're paying certain premium for miniaturization. All other factors being equal, you'll pay more for the smaller camera. Second, in most cases, 'all other factors' aren't equal. The smaller the camera, the smaller the sensor size and the less zoom you'll likely get.

The image sensor is what actually digitizes the picture. While it's most often described in megapixels, it's also measured in a very real sense by physical dimensions. SLR cameras (and a few very specific Point and Shoot cameras) have a larger image sensor than most Point and Shoot cameras.

Even if they are both listed at the same Megapixels (which these below aren't, but close), the results are quite different. Canon SX110 (9MP top) vs Canon XSi (12.1 MP). Notice the 'flecks' in the top image, and how the bottom image resolves smaller details


Canon SX110

XSi


Zoom is a slightly inexact measurement that represents how much a camera can bring a subject 'closer'. It's a relative measurement, since it compares the range to itself - the camera in question might start with a very wide angle, or start where a different camera/lens might end.

In any case, it's a matter of optics - a very small camera cannot magnify as much as a larger camera.

Sunday, March 28, 2010

The Case of the Tinted Picture

You're inside. Following the advice of the previous post, you turn on a lot of lights. The lighting *seems* fine, but you take a picture and this happens:

Tinted Shot

What went wrong?


Remember what I said earlier about cameras 'seeing' light in absolutes? It just happened again.

Fortunately, most cameras have what's called White Balance. Unless you change it, it's also set to 'Auto' - which does a fine job in certain situations - but not the one above obviously.

So how do I fix it?

If you have Photoshop, you can correct the problem somewhat using 'Curves>Auto' but it's really only half way there.

Curves Photoshop

A better option would be to fix the problem within the camera.

Bad News: You can't do anything about the shots you've already taken*.
*Unless you shot in RAW Mode
Good News: It's a better fix than Photoshop.

How?

Take a picture of something that's supposed to be white. That something should also be very close to what you're going to take a picture of. Technically it should be 18% gray, but white is easier to find and it doesn't make a huge amount of difference. You might find it helpful to put the camera in manual focus mode so it doesn't have to try and lock onto anything - it will just take the picture.

Custom White Balance

Find how to how to set 'Custom White Balance' with your particular camera. Use the picture like the one taken above for calibration.

Take another picture with an actual subject in it. It should now look like this:

Custom White Balance Fixed

Friday, March 26, 2010

Light and Cameras

Cameras love light.

How people perceive light and how cameras do is quite different. While people adjust organically to varying degrees of illumination so everything appears 'normal' - cameras take a more absolute approach.

What does this mean? While you might not notice the difference between looking around your room inside, and looking out a window - the camera does.

For this post, I'm mainly focusing on Point and Shoot cameras - as opposed to SLR - but much of the information is universally applicable.

How do cameras compensate? They do one (or more) of a few things:

Flash

If there isn't enough light, the camera makes more. Trouble is, this only works for a few feet away and it eats up the battery power. It also makes a obvious impact on the quality of the picture - it's very easy to tell when a flash is used on a point and shoot camera.

Sensitivity (ISO)
When you prevent the flash from going off in low light, the camera has other ways to adjust. The image sensor in the camera can be set to require less brightness to register a viewable image. Trade-offs for this include more noise (skittles!) in the picture and at higher settings a less natural looking shot - flatter colours and not as much variation. The highest ISO setting usually has to be set manually for these reasons. It's often better to have a sharp, albeit noisy and flat, shot than a blurry one.

Shutter Speed
If neither of the above are used - or it hits the upper limit on ISO, the camera has no choice but to keep the shutter open longer. This almost always leads to a blurry shot. You can set a 2s timer on most cameras and that will let you brace the camera better (rather than pressing the shutter) and/or (preferably and) use a tripod. Not a lot of situations lend themselves to those two tricks though.


So what else can you do?

Outside, even on a cloudy day, has significantly more light than you will find inside. If you're inside - more lights than seem necessary will really help your shots. Stand near windows, with your back to them, if you can help it. Don't blame the camera.

Thursday, March 25, 2010

Pictures for Photoframes

Without further ado, here's 454 of my better shots. They're sized at 800x480 which is a good size for widescreen photoframes. Not a bad size to see detail either, but not so big that people will be tempted to steal them for large prints.

Photoframe

Image Hosting

I've looked into a number of different sites for hosting pictures, and here's what I've found:

Facebook the 720x(up to 720x) image size isn't great - the tie-ins to commenting/news/email is nice. EDIT - Now closer to 1000x1000, sometimes. Still not huge.

Flickr is, for me, an exercise in frustration. Can't upload one file (2.3MB) via the web page. The uploader won't download (it quit twice in mid-transfer) - and even if I could get a picture on there, it wouldn't be full size - and only 200 pictures 'live' at a time - and no more than 100mb uploadable a month (without paying $$). I like the *idea* of Flickr, but can't seem to get it to work.

dotphoto while seemingly being able to upload anything, it only previews at 450px. It's geared toward 'Hosting pics - NOW YOU BUY STUFF 'KAY?'

PhotoBucket is my old standby. The free account allows for images up to 1mb (regardless of dimensions) and has only mini-thumbnails. There is a theoretical 'midsized' thumbnail but it's the large image crammed into a smaller space. Not a 'friendly' place for visitors to browse and leave comments.

ImageShack while I haven't hosted anything personally, I remember something oddly irritating about it. Oh ya. No mid-sized thumbnails again.


Picasa Web Albums


Pros: I have Picasa3. 1GB free space (more with $$), Small, Medium, FULL views (for real!)

Cons: Google takes over the world that much faster...

Working with Text/Shapes - Part I

While Photoshop has "Photo" in the name, it's also a good program for general graphic design.

A good portion of this work is, as the title suggests, Text and Shapes. Initially, these elements can be rather dull, however there's a very quick way to spice things up.

Blending Options. These can be mixed and matched as well as tweaked by a rather large number of variables. This video shows a very quick overview.



Of course, one shouldn't limit it to these basic options. Unless you really play with the initial values, it's going to look like everybody else that does the same 'just check' technique.

In the example below, I use Outer Glow (with a high 'Spread' value), Drop Shadow (with zero 'Distance' and a high 'Spread') as well as Stroke to do the bottom text in one layer.


Things that can be done in Photoshop - Part II

Fixing Image Quality

Quite a few things fall under this heading. The first being brightening/darkening.

Now, to a computer, there is a lot more information in the average picture (just jpg, not even talking RAW here) than is readily apparent to the eye. Different methods (levels, contrast) have different effects on the values assigned for the pixels colour.

Pictures can frequently be brought back to 'normal' - even if it starts by looking pretty much all black/white to start with. Extremes at either end are bad - dark pictures have 'noise' and overly bright can wash out all detail. Worth noting that I've had more success with brightening a dark picture than vice versa.

Noise. There are a lot of plugins and stand alone programs on the market to deal with the Skittle effect (taste the rainbow!). More often than not, they cost more than they are worth, since the free ones do an equally nice job. Sometimes you can get away with fixing the picture all at once, and other times, it's bad enough (will negatively impact the final image's overall colour) that it's better to apply selectively (with masks).

Chromatic aberration. If you haven't had personal experience with this, count yourself lucky. The problem with all these 'prosumers' having fancy-pants cameras is that unless you get the very expensive lenses (+$1k) you get that nasty halo around images. Particularly on the wide end of the lens and near the edges of the shot. Now Photoshop has a little thing called lens correction (which also fixes pincushion and barrel distortion) which attempts to tackle CA.

Problem is, that CA isn't a by-the-numbers type of problem. Well it is. Just very long and complicated numbers based on the lens, focal length and other controllable factors (which the camera companies do account for in their RAW correcting software), but a lot of unmeasurable factors (for all intents and purposes) like angle of light, brightness and so on.

What usually happens, at least for me, as that I get 'half-way' with the CA fix section, and get it the rest of the way the same way as I get rid of noise. Even then, a large image with a lot of people/objects can take several hours to tame the worst of it (and triply so if they didn't shoot in RAW mode).

Things that can be done in Photoshop - Part I

A lot of people are surprised by how flexible Photoshop (and other image editors) are. In this short series, I'll tackle some of the highlights

Adding and Removing content


This is basically the bread and butter of Photoshop what people usually mean when they say an image has been Photoshopped (a term Adobe dislikes). From the very small - pimples and zits and minor scratches, to the very large - people, buildings and even whole backgrounds.

Now this is pretty much without limit.

Adding pretty much boils down to matching the lighting/quality/colours of the original image.

Subtracting less than full frame elements is a tiny bit more work than adding, but as long as there is something nearby that you can clone/heal from it isn't too bad. Removing background is quite easy - green screening makes it easier still, but as long as there is some contrast between foreground and background it's a quick job regardless.

Sharp, defined edges make both of the above much easier, but if one is willing to put forth the time/effort - hair and other things are possible. They are constantly improving the "Edge Defining" of Photoshop. Until that is perfected though, a rough edge and some post work blurring and smudging makes more sense than fiddling with sliders (contrast/feather/radius/expand/contract).

Moving picture elements is basically subtracting, then adding without as much correction for light/colour needed - depending on the shot.

In this quick video, I'll show an object being removed via the clone and heal tools.

Colouring!

Let's start with a quick bit of colouring. Image borrowed from Inktank.com

I like the idea of colouring on a computer, because if you don't like it you can do it again. It's a lot easier to do various effects - a number of which can be changed after the fact.



There's also a few tricks you can do - like Multiply Layer - to let you work fast and (gasp!) sloppy and still have it look nice.



Might have to adjust your tool's presets though: