In-depth, depth of field question. Weirdness. PLEASE reply.

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This is what I mean by short side and long side 3/4 views. It gives the buyer a more clear representation. It's the same front 3/4, just a bit of a different angle. And in these shots, I purposely did the OPPOSITE of what I normally do. Do no look at the sharpness front to back on the vehicles in these pix, they have been focus stacked to maintain sharpness.
If equipment failure were not the cause, then I would assert must not be shooting straight on. However, the degree to which this is "off" is so great that I can only believe it is truly related to equipment somehow. In both images I annotated, it is so pronounced as to convince me there is no other explanation.

Can you seek out other Nikon owners and test your lenses on entirely different bodies? That would rule in or out the sensors not being seated perfectly, and lens mounts not being out of alignment.

I'll say this again - this has a significant tilt-shift or Lens Baby type of look. That can only come from equipment.
 
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If equipment failure were not the cause, then I would assert must not be shooting straight on. However, the degree to which this is "off" is so great that I can only believe it is truly related to equipment somehow. In both images I annotated, it is so pronounced as to convince me there is no other explanation.

Can you seek out other Nikon owners and test your lenses on entirely different bodies? That would rule in or out the sensors not being seated perfectly, and lens mounts not being out of alignment.

I'll say this again - this has a significant tilt-shift or Lens Baby type of look. That can only come from equipment.

And notice this. I don't use a ruler, but I line up my straight front and straight rear shots pretty damn good, and you can easily see it here.

After this weekend's testing of the D800 + 200/2 I'll move forward with other tests.

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Butlerkid

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Why not send a camera and lens in to Nikon for servicing with a card of examples showing what is occurring? Are you an NPS member? I typically get my gear back in less than 2 weeks..... That would rule out equipment problems and be quicker and more "scientific" than all the guessing going on here trying to help. ;)
 
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Why not send a camera and lens in to Nikon for servicing with a card of examples showing what is occurring? Are you an NPS member? I typically get my gear back in less than 2 weeks..... That would rule out equipment problems and be quicker and more "scientific" than all the guessing going on here trying to help. ;)

I'm not sending all my gear to Nikon for any days, let alone 2 weeks. I work for a living. lol
 
Why not try renting another body and at least one duplicate of the lenses and try that combo out, then put the rental lens on your own body and put your own lens on the rental body at the same scene, then compare all the results? Yes, it'll cost you to rent the lens and body but that is a way of checking out the situation with gear other than your own in order to make various comparisons.
 
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Just turn it upside down- as I mentioned above.
If the unsharpness moves from side to side it is the equipment.
If it does not change from side to side, it is something else.
This sure smells like equipment issues.
gary
 
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Why not try renting another body and at least one duplicate of the lenses and try that combo out, then put the rental lens on your own body and put your own lens on the rental body at the same scene, then compare all the results? Yes, it'll cost you to rent the lens and body but that is a way of checking out the situation with gear other than your own in order to make various comparisons.
Just turn it upside down- as I mentioned above.
If the unsharpness moves from side to side it is the equipment.
If it does not change from side to side, it is something else.
This sure smells like equipment issues.
gary

No place around here to rent.

I'll try to turn it upside down.
 
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I'm not sending all my gear to Nikon for any days, let alone 2 weeks. I work for a living. lol
This makes no sense to me. If you "work for a living" and this pays your bills, then you need your equipment functioning properly. Nikon has a loaner program for NPS members so you can continue working while your equipment is repaired. If you aren't a member of NPS, I suggest you apply for a membership if photography is your professional career (and I presume it is based on this discussion). Any other NPS member can sponsor you. There is a free tier, and one or two paid tiers. Their website tells you the benefits of each tier. You sound like an excellent candidate for this program.
 
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This makes no sense to me. If you "work for a living" and this pays your bills, then you need your equipment functioning properly. Nikon has a loaner program for NPS members so you can continue working while your equipment is repaired. If you aren't a member of NPS, I suggest you apply for a membership if photography is your professional career (and I presume it is based on this discussion). Any other NPS member can sponsor you. There is a free tier, and one or two paid tiers. Their website tells you the benefits of each tier. You sound like an excellent candidate for this program.

The dof doesn't bother anyone but me, and that's just because I'm OCD and like to know how things work.

I appreciate the offer, but I really don't have a need for NPS. I have a 3rd body as well, a D850, and can use that if I need to, but it's more for when my workhorse D800 finally gives up the ghost. In fact, I'm so unhappy with mirrorless that I'll end up getting an additional D850.
 
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The dof doesn't bother anyone but me, and that's just because I'm OCD and like to know how things work.

I appreciate the offer, but I really don't have a need for NPS. I have a 3rd body as well, a D850, and can use that if I need to, but it's more for when my workhorse D800 finally gives up the ghost. In fact, I'm so unhappy with mirrorless that I'll end up getting an additional D850.
Given you have a 3rd body, maybe test that one with both lenses to see what happens?
 
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I've been pondering this question and I believe I have the answer. I won't try to explain with words - I think that has been done plenty. Instead, here are two diagrams for consideration.

Constants:
  1. A car, 16 feet in length is parked perpendicular to a treeline another 16 feet behind the car
  2. A FF camera, 135mm f/2 lens shot wide open is used
  3. A horizontal FOV of 15.15 degrees
  4. Focal plane is 80' from the camera
  5. DOF near limit is 74'
  6. DOF far limit is 87'
  7. All of the above are drawn to scale precisely
  8. The D850 camera body is represented at a larger scale for clarity
Driver side view, offset 35 degrees
Automobile Photography Setup -35 degrees.jpg
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Passenger side view, offset 55 degrees
Automobile Photography Setup 55 degrees.jpg
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For me, this completely solves the mystery. Other thoughts?
 
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I've been pondering this question and I believe I have the answer. For me, this completely solves the mystery. Other thoughts?

It doesn't solve the mystery, as the mystery is why the dof is ALWAYS more shallow on the right compared to the left. But it does explain some of the dof itself.

And I think I've figured out just earlier that it's an equipment issue after all. I was mistaken thinking I've had the issue on my D800 + 200/2, it was actually my OLD D700 + 200/2. I no longer have that body, but I have the lens, and testing it just now with the D800 the DOF was correct!

So, shortly I'll go out and test the two combo's side by side; D800 + 135/2 and D810 + 200/2.

This will give us our answer if the issue is with the D810 body or the 135/2 lens, as it has to be one of them.

My gut feeling is that it's the D810 body that has the issue, and it's the same issue my D700 had years ago, but it's just much more pronounced on the D810. We'll soon see!

This was my quick test of the D800 + 200/2. Don't freak out because it's not perfect, I was on my way home from a shoot, and just stopped off to do this in 30 seconds.

I've cropped the image, and flipped one of them as well (notice the M2 logo on the grill), but you can see the DOF is not only correct, but extremely close, even for a quick test that wasn't perfect.
 

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OK my peoples, now this gets interesting. After my D800 + 200/2 test showed now difference in the DOF, I thought I had the mystery solved. But I don't.

I can say this effect is present in the picture above, but to such a minimal degree that it's not even worth mentioning.

But now I'm going to show you that this effect is present in my D800 + 135, AND my D810 + 200/2.

The first image is the D800 + 135
The second image is the D810 + 200/2

I shot from the same marked positions, did not move the tripod, and flipped the passenger's side photo in both sets to show the differences clearly.

Look at the rear wheels, nothing else, as they make it absolutely clear that shooting the car on the passenger's side gives me more dof than shooting it at the same angle, same height, same everything on the driver's side.

Things that truly make you go hmmmm....
 

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The first image is the D800 + 135
The second image is the D810 + 200/2
I see what you mean regarding the rear quarter panel and wheel being more OOF in the driver side views for both camera/lens combinations. Against your instructions, I can't help noticing that the right side of the frame is more OOF on the driver side view. In the passenger side views (which you've rendered as mirror images), the left side of the frame is more OOF, but this is consistent with an equipment issue because the left side of the mirrored frame was actually originally the right side.

Something is causing the original right side of every frame to be softer. Some of this softness is seen in the rear quarter of the driver side of the car, but it is not evident in the passenger side view because all of the driver side of the car is facing away from the camera. This could be because the driver side bumper and headlight are the only parts in the "suspect portion" of the frame. But they are at your plane of focus, where any tilt/shift effect (resulting, presumably, from equipment imperfections) will not be as noticeable as they are at the limits of your DOF.

Your testing thus far involves too many variables. In this most recent iteration, you used one lens with one body and a different lens with another body. Let's say, for simplicity's sake, that the equipment malfunction possibilities can be lumped into "camera" or "lens" which brings you to 4 possible combinations, three of which could be adversely affecting your images. These are the combinations:
  1. Camera and lens are perfectly aligned
  2. Camera misaligned
  3. Lens misaligned
  4. Camera and lens misaligned
It's actually much more than that, because there are two components in the camera that need to be aligned correctly (lens mount and sensor) and two in the lens (the various optical elements and the bayonet mount). Using two camera/lens combos muddies the water (i.e., does the fact that it happens with two different combinations mean that it always happens? No scientist would ever draw any conclusions from a sample size of two when so many variables were in the experiment). Finally, changing shooting positions between the driver side and passenger side exposures adds another question mark. Even with great care taken on your part, changing positions between shots that you intend to critically evaluate with the razor thin DOF of your f/2 telephotos risks giving you misleading results.

At the very outset, you postulated that there is some sort of optical phenomenon that causes your passenger side views to exhibit greater DOF than your driver side images. There seems to be ample evidence that it is actually an equipment issue of some sort.

Clearly you have the time, energy, and desire to get to the bottom of this. I suggest you work smarter, not harder. Simplify your test. Keep as many things constant as you can. One camera, one lens, one shooting position. You really don't even need a car. You could set up two orange cones 16 feet apart from each other at two opposite corners of a parking space, representing one side of the car, then rearrange them at the other two corners to simulate the reverse angle. Also, tighten up your distances a bit. Position your tripod close enough so that the near cone is at one edge of the frame and make sure the brick BG is not too far behind the far cone. That will make any aberrations extremely prominent.
 
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I see what you mean regarding the rear quarter panel and wheel being more OOF in the driver side views for both camera/lens combinations. Against your instructions, I can't help noticing that the right side of the frame is more OOF on the driver side view. In the passenger side views (which you've rendered as mirror images), the left side of the frame is more OOF, but this is consistent with an equipment issue because the left side of the mirrored frame was actually originally the right side.

Something is causing the original right side of every frame to be softer. Some of this softness is seen in the rear quarter of the driver side of the car, but it is not evident in the passenger side view because all of the driver side of the car is facing away from the camera. This could be because the driver side bumper and headlight are the only parts in the "suspect portion" of the frame. But they are at your plane of focus, where any tilt/shift effect (resulting, presumably, from equipment imperfections) will not be as noticeable as they are at the limits of your DOF.

Your testing thus far involves too many variables. In this most recent iteration, you used one lens with one body and a different lens with another body. Let's say, for simplicity's sake, that the equipment malfunction possibilities can be lumped into "camera" or "lens" which brings you to 4 possible combinations, three of which could be adversely affecting your images. These are the combinations:
  1. Camera and lens are perfectly aligned
  2. Camera misaligned
  3. Lens misaligned
  4. Camera and lens misaligned
It's actually much more than that, because there are two components in the camera that need to be aligned correctly (lens mount and sensor) and two in the lens (the various optical elements and the bayonet mount). Using two camera/lens combos muddies the water (i.e., does the fact that it happens with two different combinations mean that it always happens? No scientist would ever draw any conclusions from a sample size of two when so many variables were in the experiment). Finally, changing shooting positions between the driver side and passenger side exposures adds another question mark. Even with great care taken on your part, changing positions between shots that you intend to critically evaluate with the razor thin DOF of your f/2 telephotos risks giving you misleading results.

At the very outset, you postulated that there is some sort of optical phenomenon that causes your passenger side views to exhibit greater DOF than your driver side images. There seems to be ample evidence that it is actually an equipment issue of some sort.

Clearly you have the time, energy, and desire to get to the bottom of this. I suggest you work smarter, not harder. Simplify your test. Keep as many things constant as you can. One camera, one lens, one shooting position. You really don't even need a car. You could set up two orange cones 16 feet apart from each other at two opposite corners of a parking space, representing one side of the car, then rearrange them at the other two corners to simulate the reverse angle. Also, tighten up your distances a bit. Position your tripod close enough so that the near cone is at one edge of the frame and make sure the brick BG is not too far behind the far cone. That will make any aberrations extremely prominent.

Well thought out response. I've come to expect this from you.

However, I'm a fan of simplicity.

I shoot cars.

In my testing I shot a car. I used a very well-made grid to do so, and gave enough distance to be able to actually see the dof fade. I didn't change the height (I know that can have a big effect on DOF), but the parking lot (as straight as it is), isn't absolutely flat, so with the 200/2 images there is some variance. I kept almost exactly the same angle (I will post the overlays) to as near as makes no difference, and still this phenomenon persists. I can't even imagine it's not an optical phenomenon now, having seen it produced on 2 different lens/body combinations.

I might just have to settle for not knowing what it is, as I feel like I've been extremely thorough with my testing.
 

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Here are the D800 +135 images without being flipped/stacked.
 

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Here are the D810 +200 images without being flipped/stacked.
 

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