Hands up, this is a dry post that’s all tech with little action. It may not even be correct. Other notes are available.
So you’ve finally taken a pic that you want to show off? Before you start booking space on the side of that bus, you need to assess the quality of the shot you’re working with. So look at the pixel count and sensor dimensions.
My Canon 600D, shooting RAW, gives me 18M 5184 x 3456. (5184 X 3456 = 17915904; which, rounded up, equals 18M) and 300 pixels per inch (PPI). Whereas my camera phone has a spec of 12MP (1334 x 750) at 326 PPI.
Next, ask yourself what camera’s been used to take the shot: phone/compact/SLR etc. The quality of 18M on a DSLR is very different to 18M on an iPhone or 18M on a full frame.
The camera used will define just how big you can blow-up the shot. For my Canon 600D, that 18M means that “officially” I’m limited to prints of 17.28″ x 11.52″; any bigger and, by rights, there should be a reduction of quality. Whether the average viewer will notice until the point you try to wallpaper a house with it, though, is debatable.
As for camera phones? Zig, our tutor, reckons that if you’ve shot anything half-decent on a camera phone you’re pretty much xxxxx. Jim Harmer of Improvephotography.com suggests otherwise – there’s a handy chart on the website here that will give you an idea of what megapixels will do what. My view is that it depends on how close up you’re going to be viewing the work. The further back you have to stand to view something – a billboard, say – the less important precise, exact quality becomes. Think how the Impressionists (Monet and Seurat for example) created astonishing works of art. Up close, Seurat’s works just look like a load of dots (which, technically, being pointillism, they are). Meanwhile, Monet’s masterpieces break down into a series of short, choppy strokes and crazed dapples. Only in standing back from the works do you see them as the artists wished you to see them.
HIGH RES – WHAT’S THAT ALL ABOUT?
Over the years, I’ve been asked by Editors to provide “High Res” (High Resolution) shots. I’ve always taken that to mean high quality, so max file size and definitely not taken using a pinhole camera. And that is what they mean, but it turns out “High Res” as a phrase literally means **** all when it comes to quality. Resolution refers to how pixels are stored – how the information is gathered – and different cameras do it in different ways. So my Canon’s resolution is 72 pixels per inch, but its images still print at 300 ppi.
Before you can think about printing you need to ensure that you crop or resize your image from that of your camera’s sensor to the dimensions that you want to print. If you don’t do this, the printer will do a random crop to fit whatever size print you’ve ordered. Which could be a potential disaster. So, unless you want to hand over all control to your printer, don’t forget to crop your image first.
DSLR: sensor proportions are 2:3
Compact camera/point & shoot: sensor proportions are 4:3, which synced at what was then TV output proportions.
Camera phones: sensor proportions are 16:9, which sync with widescreen TV.
If you’re having your photo’s professionally printed, you’re best to opt for one of the standard-sized options available as custom-sized prints can be stupidly expensive.
So, presuming you’re using Camera Raw, here’s what you do first:
- Select crop tool and select custom option.
- Put in dimensions that you want your final print to be. Camera Raw will provide a crop setting to fit that you can then use as your baseline for selecting the image area you wish to print.
- You can then zoom into or out of your original image to select the amount of original information you wish to include while retaining the same print dimensions throughout.
- If you look at the next three photos, they are all showing a 21 x 29.7 (A4 size) potential crop. The shaded area represents the amount of the original image that I will lose, depending on how much I want to crop, but the end print will be exactly the same size. Even if I want to include as much of the original image as possible, if I want to print A4 size, I am always going to lose a strip of info.
SELECTING THE CORRECT COLOUR SPACE SETTINGS FOR YOUR FILE-TYPE
In your camera settings menu, you’ll find the Colour Space setting.
If you are shooting in RAW, the official line is that you should select SRGB.
If you are shooting Jpegs then you have to choose ADOBE RGB as this will give you better, brighter colour and tonal range.
It can be a faff to remember to switch between these two settings, though. To be safe, you can just stick with ADOBE RGB, regardless of whether or not you’re shooting Jpegs or RAW files, as when you are shooting in RAW the only info that is set rigid by your camera is the ISO. So you are always able to play around with the colour at the edit stage, regardless of the Colour Space setting.
EDITING FOR PRINTING
Gone are the days when we used to pour over our freshly-developed-at-Boots pics. Now, our images easily upload to our tablets; phones and computers in seconds. As a result, we’ve become conditioned to viewing our shots on backlit, HD screens. And that, my dears, is a completely different world of vibrancy to that inhabited by good old-fashioned “hold ’em in your hands” prints. Which is why you need to compensate when editing for printing – start off by dropping the screen brightness by half and then adjust the brightness of each image accordingly in the edit. 15% is a good starting point, but only through trial and error will you work out what level of brightness compensation works for you – and it will differ wildly from screen to screen.
SAVING EDITED FILES
When you come to save your edited files on your computer (as Jpegs, for printing), use the following settings:
- QUALITY = MAX = 12 (you may need to actually input 12 manually).
- COLOR SPACE = ADOBE RGB 1998
- Be aware that changing computers/light levels etc while editing means you’ll never have true consistency. The only way to do that is to edit in controlled, grey, artificial light. A photographic laboratory essentially.
- RESOLUTION: 300 PPI for professional prints unless lab’ specifies differently.
PRINTING IMAGES YOURSELF FROM COMPUTER TO PRINTER?
- QUALITY = MAX 12
- COLOUR SPACE = ADOBE RGB 1998
- RESIZING = as per your needs.
- RESOLUTION = our tutor, Zig said that image resolution must be equalled (if not surpassed) by that of your printer. I presume he means that you need to have at least as many dpi (dots per inch) on your printer as you do PPI (pixels per inch) as you do on your image. But I could be wrong so that’s one question for tomorrow night’s class as I haven’t really got a clue how to the whole PPI v DPI thing works.
GLOSS OR LUSTRE?
Final thing to make a call on is the finish of your print. Lustre (matt) has a softer, gentler feel. Gloss (shiny) is good for clean, sharp images.
At least, I think that is what Zig says. Going to make him read this in its rambling entirety and tell me if I’ve got things straight. Will report back, soonest.