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Focusing issue with D5600 and sigma art 50mm
#1
Posted 19 January 2019 - 09:50 PM
You can see the eyes area is good
The ears and nose are out of focus ,
Just looking for advice how to fix this
Thanks
#2
Posted 20 January 2019 - 12:30 AM
The problem is the DOF (depth of field)
You may search for DOF in this forum and find a number of good contributions, as well have a look here:
Depth of field - Wikipedia
Online Depth of Field Calculator
(Btw the eyes were in the focal plane (best distance) and are therefore sharp)
You could increase the DOF, to have more in focus, by choosing a smaller aperture (=higher number, as the aperture is expressed as a fraction) or by having more distance (but that is not an option here with that lens) to the focal plane.
- Fletch likes this
#3
Posted 20 January 2019 - 12:48 AM
#4
Posted 20 January 2019 - 01:56 AM
The Sigma 50 mm Art is f1.4. As already stated, you should stop down to 4 or 5.6 if you want nose and ears to be sharp
#5
Posted 20 January 2019 - 02:23 AM
This lens really isnt that good for a general snap and shoot with auto focus then
Nice bokeh affects just not what i was wanting out of a primary run around lens
The main reason i got this lens was for better night photos
Bit of a let down if you have to change settings to get the best photo
#6
Posted 20 January 2019 - 02:36 AM
Fast lenses are wonderful toys, but you need to think when you start to use them. The razor-thin DOF up close and wide open can be a help or a hindrance depending on your style.
The reasons that so many of us like fast primes for portraits are mostly that the short DOF W/O makes it easier to focus precisely, and that no lens is at its sharpest wide open. Everything firms up in definition by stopping down a little. An f/1.4 stopped down two steps to f/2.8 is at its sweet spot. An f/2.8 is often quite soft @2.8 and needs to be stopped down to f/4 or even 5.6 to get the full bite it is capable of.
#7
Posted 20 January 2019 - 06:02 AM
I wont give up on this lens quite yet and try it at 2.8
I was looking at a really nice lens and from the reviws its supposed to be amazing
Maybe to the pro it is , for the beginner its not so easy or great
The kit lens mine came with i feel isnt that good
Struggled to focus during night photography which was such a let down
Coming from an old pentax which done everything i threw at it im a little let down by this camera
Thought a 1.4 would help with night shots especially
Not knowing a lot about slr’s i wanted a nice beginner slr with a nice go anywhere lens
Might pay to get a 35 nikon lens maybe ??
#8
Posted 20 January 2019 - 06:21 AM
A 50 on DX is not quite a go anywhere lens as the field of view is on the narrow side. You might be better off with a 35 or even a 24. An f/1.4 or 1.8 makes shooting in available dark much easier, but the high dynamic range and relatively low noise levels at high ISO makes it less imperative to shoot at wide aperture.
What old Pentax did you have? This information can set a frame of reference as many of us have used Pentaxes before the switch to Nikon or use both at the same time.