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View Full Version : Close-up and big depth of field required...


darkroomTed
3rd April 2010, 04:59 PM
I use a 30 year-old Nikon FE.

I need a lens that enables me to sharp-focus on an object less that a foot away... but with a depth of field that keeps a building 100 yards away in focus. Any ideas?
I'll need to hire the lens, so any threads on that would be useful too.

Many thanks,
Ted

Carl V
3rd April 2010, 05:28 PM
To achieve such a great depth of field, you would be looking at an extreme wide-angle or a fisheye lens. Nikon used to make a 15mm f/3.5 'ais' lens, and this would give you the required depth of field when using it at f/22 at its hyperfocal distance.

I'm not sure of the effect you're trying to create, but I do have a 16mm f/2.8 'ais' full-frame fisheye which when set at f/22 will keep everything in focus from infinity down to under a foot (I've just had a look at the depth of field scale on the lens).

I don't know off the top of my head where you could hire such a lens, but the two I mentioned are normally readily available to buy on the used market, so I dare say you should be able to rent one without too much difficulty.

marty
3rd April 2010, 05:33 PM
Hello, Ted.
Premised I'm no expert of Nikon optics, how about Nikkor PC 35mm? Perhaps small aperture plus tilt/shift movements can reach as deep as you need. I think this lens should focus down to 30cm.

Best, M.-

Rob Archer
3rd April 2010, 05:44 PM
I once saw a kind of '1/2 close-up filter'. It was literally half a normal cu filter in a rotating frame. The idea is that half the image would be close up and the other half normally focussed. I've never used one and I suspect positioning the edge would be tricky.

Rob

Richard Gould
3rd April 2010, 07:39 PM
I would think that you would have to use an extreme wide angle,somthing like a 17 mm, stopped right down that would give you the required depth, Richard

JimW
3rd April 2010, 09:05 PM
Rightho, here's what I found. I used a wide angle (17mm) with a set of macro enabled 2x converter. Canon FD, but I'm sure the same applies. It wasn't a Canon doubler tho'... As you twisted the ring on the doubler, it moved the lens further away from the film plane. I got incredible depth of field from the lens combination.

Maris
4th April 2010, 03:40 AM
Focus from 1 foot to infinity at any aperture is a standard technique in view camera work. It is easier with a wide angle lens although in theory any lens can be used. The 35mm equivalent technique is to use a tilting lens or a tilt-shift lens. Canon have offered tilt-shift lenses for years and I believe Nikon offers one as well. Off brand lenses that offer the tilt function are made with Nikon adapters by Hartblei and possibly others.

This phenomenon of being able to simultaneously focus points at wildly different distances is a result of an optical principle termed the Scheimpflug condition. Scheimpflug is not a version of depth of field but rather a consequence of placing a tilted focus plane through the points of interest. Depth of field above and below the Scheimpflug plane (alias focus plane) is obtained by the usual expedient of stopping the lens down. Perfecting the tilts is easy via the ground glass of a view camera and I understand fiercely determined people can also do this through the viewfinder of a 35mm camera.

Argentum
4th April 2010, 07:32 AM
When using PC lenses bear in mind that depth of field is the area infront of and behind the plane of sharpest focus. When you tilt a lens those distances change into a wedge extending out from roughly the camera position and the wedge gets narrower the more you tilt the lens. So if you put the plane of sharp focus along the ground from infront of you to the horizon then the DOF wedge extends from above the plane of sharp focus and below. Well the bit below the ground is wasted so infact the plane of sharp focus needs to be placed to maximise the use of the dof wedge.
This is important because any objects with any height near the camera may be infocus at their base but not in focus at their top. i.e. they extend outside of the dof wedge. You have to do the math to work that one out in advance to know if what you are planning will work as you want.
A non PC lens won't have that limitation but may have a lot of area to be cropped out because it will be such wide angle leaving you only a very small piece of negative to work with.
You need a large format camera. ;)

Barry
4th April 2010, 09:18 AM
This (http://www.dofmaster.com/doftable.html) may help?

Argentum
4th April 2010, 10:16 AM
This (http://www.dofmaster.com/doftable.html) may help?

That is useful for normal prime lens but no good for PC lens using tilt.

You need the following:

http://en.wikipedia.org/wiki/Scheimpflug

and

http://www.trenholm.org/hmmerk/#SR

have fun:)

Dave miller
4th April 2010, 10:19 AM
That is useful for normal prime lens but no good for PC lens using tilt.

You need the following:

http://en.wikipedia.org/wiki/Scheimpflug

have fun:)

That's better, only a little mental arithmetic required with that one. :rolleyes:

Argentum
4th April 2010, 10:25 AM
That's better, only a little mental arithmetic required with that one. :rolleyes:

Well I have a rodenstock gizmo which does most of it for me.

Bob Wheeler wrote a little freebie program to do it on a palm and some other devices.

http://www.bobwheeler.com/photo/Software/software.html


But if there is nothing except flat ground between you and a building 100 yards away then no problems unless building is too high for DOF wedge. But you'll have to calculate that one.

Argentum
4th April 2010, 02:20 PM
here's the gizmo. Simple to use to check or set everything. Bit pricey nowadays.

http://www.calumetphoto.co.uk/item/365-592A/