X-Pro 2 + XF 90mm Depth Of Field Scale

[nickk]

The DOF scale on the X-Pro 2 (in both Pixel and Film format) with the XF 90mm lens simply don't work. OR I've massively misunderstood. 

The camera when I took this shot (f2, 1/480sec, iso 200) is saying the DOF is 3m but it is obviously not 3m? So confused, please help! 

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Edited June 19, 2016 by nickk

[Furtim]

Difficult to say it's not 3m away as we weren't there!

 

Just to check though - when you're saying 3m DoF are you meaning the white indicator is on the 3m mark, or the blue 'range' either side of the white indicator is spread across 3m on the scale?

 

I'm assuming you're referring to the white indicator which doesn't indicate a 3m DoF, it's the distance from the sensor to the area in focus. The blue bar either side of that white indicator (which is pretty much non existent at f2, even on film format), indicates the range either side of the area in focus that should be acceptably sharp and that constitutes the Depth of Field.

 

You have to go to F16, film and focus out to something approaching 9m to get that kind of DoF from just playing with the camera - there are plenty of on-line calculators that will give you the precise numbers.

 

[nickk]

Thank you for your reply. Very much appreciated.

This may simply be my lack of understanding of 90mm lenses but here goes:

 

If I put the XF 27mm on the camera and prepare a shot, the white indicator, as you say, shows the distance from the sensor to the area in focus. As I increase or decrease the aperture the blue bars either side of the white indicator move dramatically (showing the area in focus changing size). However when I put the XF 90mm on the camera and change the aperture the blue bars show a negligible difference between f2 and f16 at all distances. (I say all but i mean the ashtray, my gate post, the building across the street, and the tower block in the distance)

[Furtim]

Thank you for your reply. Very much appreciated.

This may simply be my lack of understanding of 90mm lenses but here goes:

 

If I put the XF 27mm on the camera and prepare a shot, the white indicator, as you say, shows the distance from the sensor to the area in focus. As I increase or decrease the aperture the blue bars either side of the white indicator move dramatically (showing the area in focus changing size). However when I put the XF 90mm on the camera and change the aperture the blue bars show a negligible difference between f2 and f16 at all distances. (I say all but i mean the ashtray, my gate post, the building across the street, and the tower block in the distance)

 

Yes - that is to be expected, and is why longer lengths are great for isolating the subject from the background.

 

The longer the focal length the shallower the depth of field for a given aperture.

[DarnGoodPhotos]

In the blue bar, the white area on either side of the red line is the approximate size of the in focus area. I say approximate because the edges of the white area won't be as sharp as the red line. Now the size of that white area should be larger at infinity (right side of the blue bar) than at 4" (left side of the blue bar). bear in mind that the 3 on the blue bar means that the subject is 3ft (or meters if you set it to that in the menus) from the camera, not that the dof is 3ft.

 

As someone said, the white area at infinity on the90mm will be smaller than the white area at 27mm.

 

It also explains why you get better isolation the further the subject is from the background.

 

If your camera/lens aren't behaving that way then there is a mechanical issue.

Edited June 19, 2016 by darngooddesign

[HarryMac]

One can always get on www.dofmaster.com and put in the variables and hit "calculate". For given apertures and distance to focus, one gets

the DOF. Then compare the limits of acceptable focus it to what is in the scale in the viewfinder.