Tag Archives: focal length

Spending time at 50mm

My latest project has been to spend time using my 50mm lens – on a full-frame camera, so it really is 50mm.  I tend to use longer focal lengths so this is the start of a move towards working with shorter lenses.  This has been a considerable challenge for me for a number of reasons.  Firstly, on a crop sensor the focal length is equivalent to about 75-80mm, and using it on a full-frame sensor makes it seem positively wide-angled!  I have to move much closer to fill the frame with my image and sometimes this just isn’t possible.  I realised I often see an image within the broader landscape and pick it out using the longer lens rather than showing the landscape in its entirety.  I don’t paint with a broad brush!  My next problem is that I like to get up close and personal to small subjects, often using a macro lens and I just can’t get close enough.  The extension tubes are tempting but that is kind of cheating!  However, on the plus side I do have a nice wide aperture of f/1.8 to play with, and my little ‘Nifty fifty’ Canon 50mm f/1.8 stays pretty sharp even wide open.

50mm is often considered to be a contemplative focal length as it is said to give the nearest to the viewpoint you get with the unaided eye.   I have however also seen this claim made for slightly shorter lengths and slightly longer ones as well, in the range 40-80mm, so I decided to test it out.  Rather than using different lenses I decided to try my 50mm lens on both a full frame and a crop sensor camera, (because I had both cameras to hand but not more lenses!).  After some serious squinting through both viewfinders trying to assess if the image in the frame was the same size or bigger/smaller than that seen with my other eye, I came to the conclusion that for me, the image created by the full frame canon 5D mark II was smaller than that seen by my eye, whereas the images I saw doing the same test using the APS-C (1.6 crop factor) Canon 550D were pretty similar in size.  So, for me at least, a slightly longer lens, about 80mm equivalent, is nearer to what I see with the naked eye.  It’s hard to define, as of course the end result then depends on the size of the final print, or how much you zoom in on screen.  So is there a contemplative print size as well, to go with the contemplative focal length?