Brian Brown
July 16th, 2011, 05:13 PM
I finally got my EOS - Nikkor adapter in the mail today, so I did a fairly-informal test on the 5 lenses I now have that can achieve a 50mm focal length... three primes and two zooms.
The original "normal" lens for the 35mm film format, becomes a 1.6x crop on my 7D, so this is a far cry from "normal" on a crop cam... more like a short tele, but since this is the easiest and cheapest lens for the manufacturers to make, we often see very fast and very sharp examples of 50mm focal lengths out there. Sooo... I wanted to see how each would perform wide-open.
Although stills shooters will seldom use a lens wide-open (since most lenses fare very poorly in terms of contrast and sharpness), for indoor video work (my primary use for my lenses), I rarely stop them down much past wide-open in order to prevent putting much ISO noise into the file. So this is actually a meaningful test for me to see how each performs wide-open.
Naturally, one might ask: "If you're using them to shoot video, why not shoot video for a wide-open test, Brian??" The truth is, it's very difficult to make a repeatable video test and also show the videos side-by-side.
So.... I shot the same bookshelf from a tripod, with a fixed white balance and shutter speed. In hindight, my methodology SHOULD have altered the shutter speed rather than the ISO (to accommodate the speed variances) in order to keep the grain the same... but, "oh well".
Likewise, I also noticed that I shot the Canon EF 50/1.8 "magic plastic" at f=2 instead of f=1.8, so it's not exactly wide-open.
Here's the following lenses used and what I paid for them:
Tamron 17-50/2.8 IS (~$600)
Canon EF 50/1.8 MkII ($125)
Canon EF 28-135/3.5 - 5.6 IS (kit lens with my 7D)
Pentax SMC 50/2 (free- my buddy Greg gave it to me from his old K1000)
Nikkor AI 50/2 ($5 at thrift store)
As a blind test, here's a full-length crop of all five lenses and also a tight crop of a single square of books on the bookshelf that enables some comparison of the "3D" quality of the lens (old stickers and tape). I'm looking out for good sharpness and contrast. There's not really corner-sharpness lens issues on a crop cam like there are on full-frame DSLRs and film.
Once you've examined the results, and given me your fave(s), I'll reveal which lens is which. This test was quite eye-opening to me, that's for sure.
Next up... a bokeh test.
Enjoy my "measure-bating",
Brian
The original "normal" lens for the 35mm film format, becomes a 1.6x crop on my 7D, so this is a far cry from "normal" on a crop cam... more like a short tele, but since this is the easiest and cheapest lens for the manufacturers to make, we often see very fast and very sharp examples of 50mm focal lengths out there. Sooo... I wanted to see how each would perform wide-open.
Although stills shooters will seldom use a lens wide-open (since most lenses fare very poorly in terms of contrast and sharpness), for indoor video work (my primary use for my lenses), I rarely stop them down much past wide-open in order to prevent putting much ISO noise into the file. So this is actually a meaningful test for me to see how each performs wide-open.
Naturally, one might ask: "If you're using them to shoot video, why not shoot video for a wide-open test, Brian??" The truth is, it's very difficult to make a repeatable video test and also show the videos side-by-side.
So.... I shot the same bookshelf from a tripod, with a fixed white balance and shutter speed. In hindight, my methodology SHOULD have altered the shutter speed rather than the ISO (to accommodate the speed variances) in order to keep the grain the same... but, "oh well".
Likewise, I also noticed that I shot the Canon EF 50/1.8 "magic plastic" at f=2 instead of f=1.8, so it's not exactly wide-open.
Here's the following lenses used and what I paid for them:
Tamron 17-50/2.8 IS (~$600)
Canon EF 50/1.8 MkII ($125)
Canon EF 28-135/3.5 - 5.6 IS (kit lens with my 7D)
Pentax SMC 50/2 (free- my buddy Greg gave it to me from his old K1000)
Nikkor AI 50/2 ($5 at thrift store)
As a blind test, here's a full-length crop of all five lenses and also a tight crop of a single square of books on the bookshelf that enables some comparison of the "3D" quality of the lens (old stickers and tape). I'm looking out for good sharpness and contrast. There's not really corner-sharpness lens issues on a crop cam like there are on full-frame DSLRs and film.
Once you've examined the results, and given me your fave(s), I'll reveal which lens is which. This test was quite eye-opening to me, that's for sure.
Next up... a bokeh test.
Enjoy my "measure-bating",
Brian