Sigma 50mm f1.4 - First Test

Started Jul 14, 2009 | Discussions thread
thx1138
thx1138 Veteran Member • Posts: 7,160
This sounds rather depressing

Reciprocal wrote:

Tokengirl,

We had a beautiful Weimaraner, but he passed in November 2007. He was adopted. A dog so human, he had about a 25-50 word vocabulary, a very special connection. He went with us everywhere. We thought we would never get over the loss.

We rescued a German short haired pointer. He's very sweet as well. Dogs have unique personalities. He goes with me everywhere. He runs with me 10-12 miles every day while I bike.

Anyway, I think you should try less MF adjustment. I think you'll find it shifts depending on the aperture.

F/1.4 = +12
F/1.8 = +8
F/2.2 to F/16 = +5

Then there's another little tip, not sure about it, but I thought I noticed the MF adjustment would drift depending on the manual position of the focus ring. I painted a mark on the focus ring. I rotated it 30 degrees between shots until I found the position where it focused accurately with the least amount of MF correction. Whenever I'm finished manual focusing, I return the ring to this home position. It shouldn't matter, and perhaps it doesn't, all I know is I get focus consistency that is equal to all my other Canon L glass. On all of them, the 70-200L F4 IS, the 17-40L, the 24-105L, I set the MF to +5. Apparently this offset is needed for the particular 5DMkII body I have. The additional adjustment for the Sigma 50mm below F/2.2 is for the shift when stopping down.

I rarely manual focus. Following the rules above, it's spot on, even in tough light. I put the center focus point over the eye, it's always accurate. It shouldn't be necessary to apply special rules but it is. Take it or leave it, that's how this lens is. That's not the only anomaly. It overexposes 1/3rd of an f-stop at F/5.6 and underexposes 1/3rd at F/1.4. I love it though. So much is said about sharpness. Not enough is said about contrast. This lens is very high contrast.

Good luck with it. We learn to communicate with our pets. I think there's a learning curve with this lens as well. I hope you try my tips, and find them useful. With the understanding I have about it, it always focuses accurately for me, even in tough situations. But I had to develop that understanding. I think if you don't, you could be back here cursing it. Give the tips a try and see what you think.

I have 11 AF lenses and essentially they are spot on with focus in one shot with my old clunker 1D II and 5D. However, when I shoot between f/1.4 and f/2.8 I always use manual focus anyway.

It really makes me nervous when I see people having to make so many adjustments on these newer bodies and that it appears to depend on distance as to what the correct setting is - that's just crazy IMO.

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