NikonGear'23
Gear Talk => Lens Talk => Topic started by: PeterN on March 29, 2016, 17:06:00
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I am seeking some help. I am thinking about buying the Nikon 85mm PC-E lens (the latest version) for watch photography. Focus stacking is an option, but not for running watches (just to be clear: the watches do not run but the seconds ;-) ). However, I can't find any information on how I can determine how much the depth of field can be extended for close-up photography with this lens. Does anyone have info (or a link). Thank you!
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Not sure I understand your question here. Depth of field is only related to f-number for magnifications greater than ~ 0.1X.
The lens goes to 1:2 (0.5X) on its own. You will not get many mm sharply rendered even when the lens is stopped down to f/16-f/22.
The tilt feature allows up to 8 degrees which will change the distribution of depth of field from a plane slab (normal to the optical axis) to a cone with apex at the entrance pupil.
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Yeah, go ahead and get the 85PC. It is money in the bank for close up photography and offers you some recul to position the camera.
We use it continuously for C/U shots.......with diffused BIG lights.
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Not sure I understand your question here. Depth of field is only related to f-number for magnifications greater than ~ 0.1X.
The lens goes to 1:2 (0.5X) on its own. You will not get many mm sharply rendered even when the lens is stopped down to f/16-f/22.
The tilt feature allows up to 8 degrees which will change the distribution of depth of field from a plane slab (normal to the optical axis) to a cone with apex at the entrance pupil.
I assume that when I align the plane of focus to the image plane, everything will be sharp, but often a watch lays flat, so I won't be able to fully align the planes (hopefully I am saying this correctly). Therefore I wonder how much DoF the 8 degrees tilt gives compared to the regular f-stop. There is a formula (I should say app) that gives you the DoF of a 'regular' lens, given aperture, sensor-size, focal length, and distance. I wonder if such a thing exists for tilt/shift lenses, If there is a single factor, that would help too.
Sorry for not beingable to express myself in a clearer way.
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You might look for the Scheimpflug principle
You do not change the DoF but the DoF is differently distributed within your picture
https://en.wikipedia.org/wiki/Scheimpflug_principle
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This is with the 28 PC, but the same [Scheimpflug] principle applies.
The closer you move the camera, the fewer degrees of freedom remain to distribute the depth of field. This is of due to the fact that the apex of the sharpness cone is locked to the entrance pupil.
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Tat looks impressive.
I've ordered the 85 and will try to better understand the math. Links are helpful! But probably experimentation works better for me. ;-)
Thanks for all help
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There are two tips to consider.
1. Do not lower the camera standpoint too much. The lower the fewer opportunities remain to distribute sharpness as you intend.
2. Think in terms of principal planes that intersect: one along the optical axis, one parallel to the film plane, one along the chief dimension off the subject.
Experimentation is a necessity. Pay attention to front and back of the framed view. It is easy to get the one or the other properly aligned and sharp, but you wish both.
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I have the older D version of this lens (not that I need it, it's a huge indulgence), and although the instructions for this lens give ordinary depth of field charts, there is nothing comparable for tilt. I think the problem is that the variations of distance, tilt, and subject angle, not to mention useful depth of field, are so great that it's nearly impossible to quantify. It certainly does work, in varying degrees, and it's a grand lens, but I don't know of any charts for the tilt. I don't know about the newer one, but the old one goes to an astounding F45, which of course introduces a lot of diffraction, but gives some unusual depth of field.
Is there any place available to you for renting one?
I did a very quick and dirty comparison with mine. This lens is a little difficult to use, heavy and prone to vibration, and it's not really ideal on a D3200 either. By comparison, on something like an F4, it sings as a hand held macro lens. Ignore the color shifts, as I do not have a proper TTL flash. Obviously, there is also no middle ground shown here, but as you can see, the change is pretty dramatic at F2.8 (effectively more like 4), and the depth of field considerable at F45 with or without the tilt. Diffraction loss occurs, but you can still see pretty good detail.
e.t.a. apologies, forgot to say what is shown. First pair is straight at F2.8 nominal straight on and shifted. Second pair is Same tripod position, 45 nominal straight and shifted, moved to center on the same point (the hyphen below the filled-in 0). I keep mixing things up, so if you just read my first edit, please note second edit change....and further edit to add, with apologies because I actually do have some post accident brain damage that makes me mix up words! When I said "shifted" I of course meant "tilted." Duh.
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This article gives you an overview of what happens when you tilt the lens:
http://www.cambridgeincolour.com/tutorials/tilt-shift-lenses2.htm (http://www.cambridgeincolour.com/tutorials/tilt-shift-lenses2.htm)
I have both the 85mm and 24mm PC-E, they are both excellent lenses, but can be a bit fiddly and slow in use (which often is an advantage - slow photography gives you time to think and rethink before you press the shutter.)
Tilt/shift lenses can produce photos that other "normal" lenses can't. And they are perfect for landscapes, of course.
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I've ordered the 85 and will try to better understand the math. Links are helpful! But probably experimentation works better for me. ;-)
Learning Scheimpflug got much easier these days as all modern cameras offer tethering and you can use a big screen as a finder.
Let Bjørns words sink in until you understand Scheimpflug by intuition ... matching the planes inside your imagination is #1 ... second is to learn about lighting and reflex management ... lots of black cloth and basic physics are your friend here.
These are taken with the big brother of the 85PC, the AMED Large Format Nikkor 120/F=5.6 (original size):
https://c2.staticflickr.com/4/3129/3167783828_b5f83eeb4d_o.jpg
https://c2.staticflickr.com/2/1006/3167789580_76cb8b1a08_o.jpg
and small versions:
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Thank you very, very much. That is very helpful.
I had not thought of three planes intersecting (just 2 in my mind)
Actually, I think I will like the experimentation with settings, finding the right angles and position. But the results are impressive.
I will do more reading until the lens arrives.
Thanks again.
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Also, have a look at the TiltLens app for iPhone.
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It's an excellent lens. Takes some study to get it to fo what you want. Avoid a common error of tilting it to much.
You'll love it. 😊
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... Avoid a common error of tilting it to much. ...
This usually happens because the camera standpoint has been lowered too much.
Applying Scheimpflug is an iterative process, and if you start the process outside the possible parameters, you cannot get it to converge to a final solution.
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Well the lens has arrived, so I will try to learn from your wise lessons and recommendations!
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I got the lens. And as said it takes time to learn and experiment! I am trying to think of the planes and avoid holding the camera too much (indeed a tempting thing to do). And focusing is a challenge, even with live view.
The lens is sharp but I noticed quite some CA. Perhaps because I shot wide open (which occurred accidentally because I forgot to select the wanted aperture after focusing ;-) ). But it's much more than e.g. the 60mm and 105 macro lenses.
I am going to write down my findings and questions so I will probably be back with some questions!
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The lens is sharp but I noticed quite some CA. Perhaps because I shot wide open (which occurred accidentally because I forgot to select the wanted aperture after focusing ;-) ). But it's much more than e.g. the 60mm and 105 macro lenses.
You know that the lens has automatic (electronic) aperture? Turn the aperture ring to L (beyond f/32), and you can adjust the aperture on the camera like any other automatic lens.
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You know that the lens has automatic (electronic) aperture? Turn the aperture ring to L (beyond f/32), and you can adjust the aperture on the camera like any other automatic lens.
aha. I had missed that. Thank you!
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Here is one of the first photos I took with the 85mm PC-E, showing the root system of carrots.