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Sigma 150mm f2.8 APO DG EX
Last Update: 27 February 2005 02:54 PM
5 comment(s)
Author: James Wiseman
Review Item: Sigma 150mm f2.8 APO DG EX
Camera: For Canon and Nikon
I recently purchased a Canon 20D and a Canon 1DmkII. Since I'm used to using the 105mm Nikkor on a 1.5x cropped camera, I wanted something that would give me a similar field of view when used on a full frame camera as I hope to own one in the future. Sigma just released a new macro lens called the 150mm f2.8 APO DG HSM (it's quite a mouthful) at a price of $600. I purchased this macro lens based on advice from Wetpixel moderator Craig Jones. It uses an ultrasonic motor for focusing, so FTMF is possible, and it's also an internal focusing lens, so the front doesn't rack out. I believe it is the fastest macro lens at this focal length and working distance.
Since I have two 8 megapixel cameras, one with a 1.25x cropped sensor, and one with a 1.6x cropped sensor, I decided to take some test photos to see what the lens is cabable of. The first set of photos was taken with the 20D and the second set with the 1DmkII:
20D Test Photos
In air, close focus with the Sigma 150 yields a field of view of about 22 mm
With the Canon 500D diopter mounted the far focus (lens focused at infinity) field of view is restricted to a field of ~87mm
With the Canon 500D diopter mounted, the close focus field of view is an astounding 16mm!
1DmkII Test Photos
On the 1D, in air, close focus with the Sigma 150 yields a field of view of about 28 mm
On the 1D, with the Canon 500D diopter mounted, the far focus (lens focused at infinity) field of view is restricted to a field of ~112mm
On the 1D, with the Canon 500D diopter mounted, the close focus field of view is about 20mm
Multiply these numbers by ~3/4 to get the field of focus behind a flat port. This will need to be tested in water to make sure that the close focus distance is not changed by shooting underwater. That's a test for another day though - hopefully on a real dive. One thing is clear though, regardless of which camera you use, this lens will shoot greater than 1:1 (35mm equivalent). In the meantime - what these tests tell me is that this lens is going to be excellent for underwater macro photography. Because of its fast f2.8 aperture, it should be able to AF in many situations. When used in MF, and in combination with a teleconverter, wet-mate diopter, or both, this lens will be capable of very high magnification.
Perhaps I’m missing something, but if both this lens and the 100mm are 1:1 lenses, then they shoud cover the same area when at closest focus. The 150mm will just give you more standoff distance. Right? Sure enough, when I put the 100mm on my 10D, the closest focus gives me, 22mm, which corresponds nicely to 1:1 on the size of an APS-C-sized “frame” (22mmx15mm) . . .
Posted by on 02/16 at 10:59 AMYep, you got it Mike. The difference is working distance - the 150mm will give you more. When you put a diopter on a lens w/ more working distance, you get more magnification at close focus distance than 1:1
Example: The 60mm Nikkor is 1:1 but very close to the lens tip. The 105 is 1:1 at about 8” from the lens tip, the 200mm it’s something like 20” or so. With the 60mm you can forget about using diopters as it’s just too close. With the 105mm, you get good magnification - greater than 1:1 (incidentally, that’s how I got my Hon Mention SEA2005 shot). With a 150mm, you get great results w/ a +1 or +2 (Canon 500D) diopter.
Cheers
JamesPosted by James Wiseman on 02/17 at 11:43 AM-
Posted by Mike Veitch on 02/19 at 02:07 PM
Ahh James? I use my 60mm and a +4 all the time. It is difficult (ie pain in the ass) and the working distance severely limits subject matter but...until i receive my 105mm (next week i hope) i am stuck using it and it is certainly doable.
Good article by the way, nicely laid out and easy to understand.
Posted by Mike Veitch on 02/19 at 02:13 PMThe tests in the <url="http://wetpixel.com/forums/index.php?showtopic=7566&pid=48189&mode=threaded&show;=&st;=&#e;ntry48189;">macro close up thread</url> certainly indicate that closest focus goes up by 4/3 so that magnification stays constant behind a port.
Posted by CeeDave on 02/27 at 04:54 PM