DOF Question at DVinfo.net

Chad Dyle · February 18th, 2009, 04:48 PM

I've been having some trouble pulling focus on the D90. The lenses that I'm currently using are:
Nikon 50mm 1.4
Nikon 80mm 1.8
Sigma 28mm 2.8
Nikon 60mm Macro 2.8

How do you adjust the DoF on the camera? I've seen in stills how you can have the subjects nose in focus but their eye out of focus. I don't need it to be that shallow. I'm using this for detail shots during the bridal prep as well as some shots during the ceremony reception. The ceremony/reception shots are usually pretty wide shots in the church or reception hall. It just seems that I'm not getting focus right. Any thoughts? I bought a Varizoom 7" monitor to attach to the camera, but it looks horrible and doesn't help. The Ikan 8000 looks a little better.

Ethan Cooper · February 18th, 2009, 08:22 PM

Chad - I'm over simplifying and I'm sure someone else can break it down far more scientifically but generally speaking the lower your f-stop, the shallower your DOF for a given lens. Also generally speaking, the more telephoto the lens the shallower the DOF at a given f-stop.

So to make focusing on the fly at a wedding easier you'd want to stop down a little and use a wider lens, that way you'd have a little more wiggle room. Either that or stop everything, bust out a measuring tape and adjust focus any time the bride or groom moves.

As far as monitoring goes, you'd ideally have a fairly large, high resolution one around. The nice little screen on the D90 is very hard to pull accurate focus on especially if you have a moving subject. I'd recommend the 17" Panasonic field monitor if it wasn't wedding work. I'm not that familiar with little ones that would work better for your application. I'm sure they exist. Marshall makes good ones if I remember correctly, but they're not cheap like the iKan or Varizoom.

You're now dealing with issues that the much sought after 35mm DOF brings to a production, and a live production at that. I tend to hope I'm close and then sharpen things up a little in post if my focus was a little off. My sharpener of choice these days is included in the free TMTS plugins, it's called Smooth and Sharp or something like that. Seems to do a nice job without making it too videoish looking.

I'm sure someone can get more technical and break things down further.

February 18th, 2009, 04:48 PM	#1
Chad Dyle Major Player Join Date: Jun 2007 Location: New Orleans, LA Posts: 410	DOF Question I've been having some trouble pulling focus on the D90. The lenses that I'm currently using are: Nikon 50mm 1.4 Nikon 80mm 1.8 Sigma 28mm 2.8 Nikon 60mm Macro 2.8 How do you adjust the DoF on the camera? I've seen in stills how you can have the subjects nose in focus but their eye out of focus. I don't need it to be that shallow. I'm using this for detail shots during the bridal prep as well as some shots during the ceremony reception. The ceremony/reception shots are usually pretty wide shots in the church or reception hall. It just seems that I'm not getting focus right. Any thoughts? I bought a Varizoom 7" monitor to attach to the camera, but it looks horrible and doesn't help. The Ikan 8000 looks a little better. __________________ www.chaddyle.com www.chaddyleproductions.com

February 18th, 2009, 08:22 PM	#2
Ethan Cooper Trustee Join Date: Dec 2003 Location: Houma, La. Posts: 1,400 Images: 5	Chad - I'm over simplifying and I'm sure someone else can break it down far more scientifically but generally speaking the lower your f-stop, the shallower your DOF for a given lens. Also generally speaking, the more telephoto the lens the shallower the DOF at a given f-stop. So to make focusing on the fly at a wedding easier you'd want to stop down a little and use a wider lens, that way you'd have a little more wiggle room. Either that or stop everything, bust out a measuring tape and adjust focus any time the bride or groom moves. As far as monitoring goes, you'd ideally have a fairly large, high resolution one around. The nice little screen on the D90 is very hard to pull accurate focus on especially if you have a moving subject. I'd recommend the 17" Panasonic field monitor if it wasn't wedding work. I'm not that familiar with little ones that would work better for your application. I'm sure they exist. Marshall makes good ones if I remember correctly, but they're not cheap like the iKan or Varizoom. You're now dealing with issues that the much sought after 35mm DOF brings to a production, and a live production at that. I tend to hope I'm close and then sharpen things up a little in post if my focus was a little off. My sharpener of choice these days is included in the free TMTS plugins, it's called Smooth and Sharp or something like that. Seems to do a nice job without making it too videoish looking. I'm sure someone can get more technical and break things down further. __________________ ∅ -Ethan Cooper

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