December 10, 2017, 11:04:38 PM

Author Topic: PhotoZone casts more doubt on 14mm f/1.8 Art AF  (Read 1225 times)

YuengLinger

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PhotoZone casts more doubt on 14mm f/1.8 Art AF
« on: November 20, 2017, 06:28:19 AM »
http://www.photozone.de/canon_eos_ff/1025-sigma14f18art?start=2

Maybe it's just Canon and Sigma combo?

I was excited about this lens for events and environmental portraiture.  Less so the more reviews I read.

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PhotoZone casts more doubt on 14mm f/1.8 Art AF
« on: November 20, 2017, 06:28:19 AM »

ahsanford

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Re: PhotoZone casts more doubt on 14mm f/1.8 Art AF
« Reply #1 on: November 20, 2017, 12:16:04 PM »
http://www.photozone.de/canon_eos_ff/1025-sigma14f18art?start=2

Maybe it's just Canon and Sigma combo?

I was excited about this lens for events and environmental portraiture.  Less so the more reviews I read.

LensTip had some trouble as well, but not alarmingly so.  But they didn't go out of their way with low light in this writeup (they have for some other lenses):

https://www.lenstip.com/506.10-Lens_review-Sigma_A_14_mm_f_1.8_DG_HSM_Autofocus.html

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YuengLinger

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Re: PhotoZone casts more doubt on 14mm f/1.8 Art AF
« Reply #2 on: November 20, 2017, 04:01:02 PM »
Low light is a big reason to go with very fast lenses.

ahsanford

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Re: PhotoZone casts more doubt on 14mm f/1.8 Art AF
« Reply #3 on: November 20, 2017, 04:16:25 PM »
Low light is a big reason to go with very fast lenses.

Sure, but I think it all depends on why you are buying a 14 prime:

Astro:  don't care about AF
Tripod landscape:  don't care about AF
Handheld landscape:  hope it's accurate, but you are generally stopping down...
Events / concerts / sports:  must be accurate

So some folks may not give a damn about AF accuracy at this FL. 

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SecureGSM

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Re: PhotoZone casts more doubt on 14mm f/1.8 Art AF
« Reply #4 on: November 20, 2017, 05:56:31 PM »
for low light events shooting with such a wide lens and wide open, what you do is you prefocus to a certain distance, say at 2.6 meters ( 8.5 feet, whatever) this gives at 14mm and F1.8 a very generous depth of field being: 1.5 meters to 8.8 meters. Plenty enough! Set the lens to MF. AF accuracy aside, it takes longer for AF to kick in when it is really dark. that is how we shoot the dance floor. I hope it makes sense.

in addition, such a wide lenses are always AF inaccurate due to AF point covers larger area of the setting. Canon AF point size is roughly 2-3 percent of the viewfinder last time I checked. 14mm lens FOV is approx. 114 degrees diagonally. so that is a massive 2-3 degree. what the lens will focus on remains to be seen. Spot-AF should be more appropriate in this case to use but known to struggle in low light and in AI Servo mode.

raptor3x

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Re: PhotoZone casts more doubt on 14mm f/1.8 Art AF
« Reply #5 on: November 20, 2017, 06:10:31 PM »
I really doubt some of the Photozone results with the 5DsR.  I have an extremely hard time believing that lenses are resolving less information out in the corners on the 5DsR than on the 5D3.  Something doesn't seem right with their testing methodology.
Bodies: X-T1, E-M1, E-M1ii, Pen-F Lenses:  µ.Z 7-14 2.8, µ.Z 12-40 2.8, µ.Z 17 1.8, µ.Z 25 1.2, X 18-55 2.8-4, µ.Z 40-150 2.8, µ.Z 60 2.8, µ.Z 75 1.8, Z 150 2.0, µ.Z 300 4.0

YuengLinger

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Re: PhotoZone casts more doubt on 14mm f/1.8 Art AF
« Reply #6 on: November 20, 2017, 06:15:31 PM »
for low light events shooting with such a wide lens and wide open, what you do is you prefocus to a certain distance, say at 2.6 meters ( 8.5 feet, whatever) this gives at 14mm and F1.8 a very generous depth of field being: 1.5 meters to 8.8 meters. Plenty enough! Set the lens to MF. AF accuracy aside, it takes longer for AF to kick in when it is really dark. that is how we shoot the dance floor. I hope it makes sense.

in addition, such a wide lenses are always AF inaccurate due to AF point covers larger area of the setting. Canon AF point size is roughly 2-3 percent of the viewfinder last time I checked. 14mm lens FOV is approx. 114 degrees diagonally. so that is a massive 2-3 degree. what the lens will focus on remains to be seen. Spot-AF should be more appropriate in this case to use but known to struggle in low light and in AI Servo mode.

Could you be any more hypothetical?  Two reputable reviews--at least--point out the AF is not reliable.  Sigma at bat!

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Re: PhotoZone casts more doubt on 14mm f/1.8 Art AF
« Reply #6 on: November 20, 2017, 06:15:31 PM »

Hector1970

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Re: PhotoZone casts more doubt on 14mm f/1.8 Art AF
« Reply #7 on: November 28, 2017, 07:13:30 AM »
I’ve used it mainly for Astro and Landscape.
For Astro it’s been manual focus. I’m really happy with it. Very impressive results. I have a Samyang 14mm 2.8.
I used it as well for landscape and it autofocussed perfectly and is very sharp. It would have been stopped down a bit.
I don’t use it for anything else. 14mm is wide I wouldn’t have thought of using it for a concert.
I’d highly recommend it. Not being able to use front filters is a negative and it’s expensive.
It was brilliant for shooting Aurora. It had the stars and the Aurora.

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Re: PhotoZone casts more doubt on 14mm f/1.8 Art AF
« Reply #7 on: November 28, 2017, 07:13:30 AM »