Okay, so what do these images show? Mainly they show the differences in distortion, magnification, angle of view and image quality of the lenses that I have in my stable. I performed the test to, as closely as possible, take exactly the same shot with each lens (oops, I left out the Voigtlander 40mm f/2) and see how they compared.
What does this sort of tedious exercise demonstrate? Well, it shows that focal length not only effect the angle of view that you see out of the camera’s viewfinder, but also magnification. A 50mm lens is regarded as a normal lens with something close to 1:1 magnification. Therefore, a 200mm lens has about 4x magnification and the 500 shown here has close to 10x magnification. Any photographer worth their salt would understand this but sometimes it is helpful to see it demonstrated as opposed to reading about it on an angle of view chart. For the pixel peepers among us, it lets you see the differences in various characteristics of the different lenses.
An interesting test to do along side this one would be to take a couple of zoom lenses that covered the range of focal lengths shown and set them at these focal lengths to see if much difference was discernible. I am not looking down my nose at people who shoot zooms, some of my best friends are primarily zoom shooters… But, I prefer prime lenses, or lenses with a fixed focal length. They don’t zoom but what you lose in versatility you generally make up in image quality and wider apertures. Zooms have a lot more moving parts that have to function across a wide range of focal lengths. This has two down-sides. One, there is more glass. And the more glass that light passes through the more the image degrades. Also, because of optical/mechanical limitations they tend to have more narrow apertures which makes then somewhat less useful in lower light conditions. Really, it’s just a matter of choice and I have chosen to shoot prime lenses. That is not to say I haven’t borrowed a zoom when the shoot required it, but it is not my preference.
There are a few things you should understand when looking at these images. First, I did very minimal adjustments to them. Mainly they are just converted from RAW images to JPEGs. They have all been straightened just a bit (because I am compulsive) and a few were exposure corrected to try to create similar lighting conditions/appearances. This was mainly done on the manual lenses that refused to play nice with Canon’s metering software. All the shots were at f/4 because that was the aperute ring I had for the Lensbaby Optics, the exception being Opteka 500mm which is fixed at f/6.3 and I wanted the settings to be as similar as possible. I guess that is about all you need to know. Behold the logarithmic changes in angle of view and magnification that come with different focal lengths!
NOTE: EXIF data on the manual focus lenses generally state that they are Canon EF 50mm f/1.8 USM II’s or “plastic fantastics.” This is not really the case. It is simply a legacy of the chip used on their adaptor rings that allows Canon camera body’s Auto Focus to function, so don’t freak out.
Various Lensbaby Optics and Other Fun Things