Jump to content

Welcome to NikonForums.com
Register now to gain access to all of our features. Once registered and logged in, you will be able to create topics, post replies to existing threads, give reputation to your fellow members, get your own private messenger, post status updates, manage your profile and so much more. If you already have an account, login here - otherwise create an account for free today!
Photo

Focusing issue with D5600 and sigma art 50mm


  • Please log in to reply
7 replies to this topic

#1
onlinejames

onlinejames

    New Member

  • Forum Member
  • Pip
  • 8 posts
  • Country Flag
As per the photo
You can see the eyes area is good
The ears and nose are out of focus ,
Just looking for advice how to fix this
Thanks05674FDA-5C6D-48DE-B85C-73E856CF1C60.jpeg

#2
Jerry_

Jerry_

    Nikonian

  • Forum Member
  • PipPipPipPipPipPipPipPip
  • 1,524 posts
  • Country Flag
How close have you been and what was the aperture?

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.

#3
Fletch

Fletch

    Forum Veteran

  • Forum Member
  • PipPipPipPipPipPipPip
  • 404 posts
  • Country Flag
  • LocationHawaii
Isn’t that lens a f1.8 ? If you shot this at or close to the f1.8 it’s exactly as Jerry says.

#4
Bengan

Bengan

    Forum Veteran

  • Forum Member
  • PipPipPipPipPipPipPip
  • 605 posts
  • Country Flag
  • LocationStockholm

Site Supporter

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
onlinejames

onlinejames

    New Member

  • Forum Member
  • Pip
  • 8 posts
  • Country Flag
Thanks for everything
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
Merco_61

Merco_61

    Nikonian

  • Premium Member
  • PipPipPipPipPipPipPipPip
  • 10,589 posts
  • Country Flag
  • LocationUppsala, Sweden

Site Supporter

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
onlinejames

onlinejames

    New Member

  • Forum Member
  • Pip
  • 8 posts
  • Country Flag
Thank you Merco
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
Merco_61

Merco_61

    Nikonian

  • Premium Member
  • PipPipPipPipPipPipPipPip
  • 10,589 posts
  • Country Flag
  • LocationUppsala, Sweden

Site Supporter

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.