Example of different jpg compression settings: Normal, Fine and SuperFine
The main drawback of digital photography is that all those menus and choices are baffling, especially to the novice. In the days of film, a point and shoot camera meant just that. No fuss, no muss, just pick up the camera, stick in the film, point, and shoot. Take your film to the lab, and as the old Kodak saying goes, “You push the button, we do the rest.” Now, there are several menus and camera functions to scroll through before you start taking any photos. To get the best images from your camera, it’s good to understand what all the functions mean and do.
Today I’m going to explain and give examples of what the various quality (or compression) settings for jpg files mean on your camera. Your camera typically has two settings that have to do with the capture of the images. They are file size and file quality.
Size Matters
File size has to do with the pixel dimensions of the file. Most people understand that part. For example, a 12 mega pixel camera would have a pixel dimension of 3000 x 4000 pixels. 3000 multiplied by 4000 equals 12 million, that’s where 12 mega pixels comes from (mega = million). You can choose various file dimensions when you are setting up your camera to take pictures. If you just need small snaps of a party, then you wouldn’t need such big files, but on your trip to Niagara Falls, you probably would, because you might make a large print for your wall one day. Here are some typical file sizes to make certain sizes of prints:
- 4×6 inch print: 800 x 1200 pixels
- 5×7 inch print: 1000 x 1400 pixels
- 8×10 inch print: 1600 x 2000 pixels
- 11×14 inch print: 2200 x 2800 pixels
These dimensions above are for a 200 ppi file. I like to print at 300 ppi, but very few people will notice the difference, especially if your image is exposed properly and of good quality. That brings me to the main point of this post – compression quality.
Quality Matters
Have a look at the three images above. The first photo was taken with the camera on “Normal”, the second on “Fine”, and the last one on “Superfine” quality settings. What you notice is that on the “Normal” setting, artifacts (sometimes mistaken for pixelation) occur around the edges of the tree branches. This disappears somewhat on the “Fine” example, and is almost unnoticeable on the “Superfine” example. If you cannot see the differences at this size, click the photo and zoom in with your browser. By the way pixelation happens when you view an image at 200%. What you are looking at are enlarged pixels, or squares, and the image looks “steppy”. Artifacts have an uneven pattern to them. You may notice both artifacts and pixels when viewing an image larger than 100% – i.e. zooming-in to the photo a lot.
Artifacts show up most when you have a solid colour in your photo, such as a blue sky or red car. When compressing, the camera averages out the colours in an area and literally throws out some of the similar colours and decides some colours can stay. This causes bands of colour in smooth gradations. For example, a nice blue sky going from deep blue to a lighter blue, may show banding, especially if the photo has been put on a web site, where typically the quality is less than Superfine. You likely won’t notice artifacts if your image has lots of detail in it, like trees with leaves, unless you zoom in really deep.
One last note. There is no standard way to describe compression. Camera manufacturers use all sorts of terms. Here are a few I’ve come across, but there are several more.
- Normal – Fine – Superfine
- Basic – Normal – Fine
- Good – Better – Best
Consult your camera manual to determine which is the best possible quality. My advice: Set your camera on the best possible quality and always leave it there. You can always change the file size, if you need to fit more photos on your memory card.
