BackdoorArts
Senior Member
I wasn't whether to post this under the Telephoto forum for the lens+TC information or under D500 forum because that's what I'm using with it, but since the thread will eventually have images I thought I'd post it here.
Last week I found an "as new" Sigma 1.4x TC for less than half retail and decided to take a chance with it and the 150-600mm f/5-6.3 Sport. The effectively makes it 210-840mm f/7-9, so I knew that at the long end I might be testing the auto-focus capabilities of the camera. Both the D750 and D500 are supposed to be able to do f/8 at the center spot, so I figured (with fingers crossed) that the D500 would at least be good on the center spot in decent light and hopefully some shadows. The TC arrived on Friday, an overcast day here in NJ. After work I put the converter on the lens and brought it out back onto the deck to see what's what.
The first thing I decided to do was throw caution to the wind and point it at a feeder hidden under the leaves, one that is completely in shadows even with full sun and just about blending in with the background with the overcast skies. I stretched it to 600mm (i.e. 840mm f/9, and effectively 1260mm on the DX body) pressed the focus button and bam, it snapped right in focus. No matter what I pointed it at, no focus hunting (OK, except the nondescript gray skies). I was both relieved and more than a little impressed.
OK, smarty, how about other focus points? No problemo. Even on overcast skies shooting in between deck rails it focused!!
I haven't done a serious test of sharpness with and without it yet, mainly because skies have been so gray that I've had to shoot consistently over ISO 12600 handheld with it. Suffice it to say, wide open it's as sharp or sharper than the 150-500mm was at its best.
Here's a completely unscientific example taken handheld into my neighbor's garage. Lightroom NR applied only, 1:1 zoom.
I think I can live with this when I need it.
Last week I found an "as new" Sigma 1.4x TC for less than half retail and decided to take a chance with it and the 150-600mm f/5-6.3 Sport. The effectively makes it 210-840mm f/7-9, so I knew that at the long end I might be testing the auto-focus capabilities of the camera. Both the D750 and D500 are supposed to be able to do f/8 at the center spot, so I figured (with fingers crossed) that the D500 would at least be good on the center spot in decent light and hopefully some shadows. The TC arrived on Friday, an overcast day here in NJ. After work I put the converter on the lens and brought it out back onto the deck to see what's what.
The first thing I decided to do was throw caution to the wind and point it at a feeder hidden under the leaves, one that is completely in shadows even with full sun and just about blending in with the background with the overcast skies. I stretched it to 600mm (i.e. 840mm f/9, and effectively 1260mm on the DX body) pressed the focus button and bam, it snapped right in focus. No matter what I pointed it at, no focus hunting (OK, except the nondescript gray skies). I was both relieved and more than a little impressed.
OK, smarty, how about other focus points? No problemo. Even on overcast skies shooting in between deck rails it focused!!
I haven't done a serious test of sharpness with and without it yet, mainly because skies have been so gray that I've had to shoot consistently over ISO 12600 handheld with it. Suffice it to say, wide open it's as sharp or sharper than the 150-500mm was at its best.
Here's a completely unscientific example taken handheld into my neighbor's garage. Lightroom NR applied only, 1:1 zoom.
I think I can live with this when I need it.