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TheDoubler55

macrumors 6502
Oct 21, 2011
340
165
image1.JPG

Canon 70d and 50mm
 

kallisti

macrumors 68000
Apr 22, 2003
1,751
6,670
Nice shot, I often play with my 50/1.4 Nikon seeing how I can shift the emphasis in the shot with focus - mucho annoying when the camera chooses the wrong spot so I normally shoot in single-point, single focus and have the camera set to focus priority.

What AF point and mode did you use? Did you look to see which focus points the camera used?

Sorry if I wasn't clear. I was using a single focus point. The Sigma sometimes just doesn't engage auto-focus on my D810. For this shot I tried various placement of the AF sensor on my son's face, but still nothing. AF did engage when I tilted down to grab the toy and then recomposed. Doesnt happen the majority of the time, but happens enough that I'm now soured on the lens. Doesn't happen with any of my Nikon lenses in similar light/subject contrast. Haven't done a controlled test in varying light and with subjects of varying contrast, or with using LV for AF. I'm not interested in performing QA for Sigma, I just need the lens to work ;)

Could just be a bad copy, but I've seen several posts of people experiencing the same behavior with this lens (and I think the 50mm f/1.4 Art too). I own the latter lens and it happens with it as well. Bought the two too close together to have noticed the issue between purchases. Uncommon enough with both lenses that it took me awhile to notice a pattern. But after some time using both, the frustration factor from missed shots has pushed me over the edge.

The release mode is somewhat beside the point as it isn't an issue of whether the shutter trips or not, but rather whether AF will engage at all for the selected focus point. Similarly it's not an issue of continuous vs single acquisition AF.

I appreciate your experience with the "auto" focus point selection. I've experienced the same thing--often it nails it but at times it misses spectacularly ;)
 

kenoh

macrumors 604
Jul 18, 2008
6,507
10,850
Glasgow, UK
Sorry if I wasn't clear. I was using a single focus point. The Sigma sometimes just doesn't engage auto-focus on my D810. For this shot I tried various placement of the AF sensor on my son's face, but still nothing. AF did engage when I tilted down to grab the toy and then recomposed. Doesnt happen the majority of the time, but happens enough that I'm now soured on the lens. Doesn't happen with any of my Nikon lenses in similar light/subject contrast. Haven't done a controlled test in varying light and with subjects of varying contrast, or with using LV for AF. I'm not interested in performing QA for Sigma, I just need the lens to work ;)

Could just be a bad copy, but I've seen several posts of people experiencing the same behavior with this lens (and I think the 50mm f/1.4 Art too). I own the latter lens and it happens with it as well. Bought the two too close together to have noticed the issue between purchases. Uncommon enough with both lenses that it took me awhile to notice a pattern. But after some time using both, the frustration factor from missed shots has pushed me over the edge.

The release mode is somewhat beside the point as it isn't an issue of whether the shutter trips or not, but rather whether AF will engage at all for the selected focus point. Similarly it's not an issue of continuous vs single acquisition AF.

I appreciate your experience with the "auto" focus point selection. I've experienced the same thing--often it nails it but at times it misses spectacularly ;)

That sounds too unreliable to continue with. They behave on other cameras. On the net it is a somthing of a D8x0 and laens combo issue isnt it?

Sounds like going back to a Nikon on Nikon combination is the best bet.

The little guy is going to be doing too much cutage right now to be missing it through camera faffing...
 

Doylem

macrumors 68040
Dec 30, 2006
3,858
3,642
Wherever I hang my hat...
Am I right in thinking you've been here before? It reminds me of another you posted a while back.

No... I've driven past it before... but never stopped to take a photo. Of course, these old pele towers (they say 'tower houses in Scotland) were built for solid defence, not for decoration, so they tend to look pretty similar...
 
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