Nikon D7200 360 Deg Product Shoot - Mirror Moving? Shots dropping vertically??

Hi


I have a Nikon D7200 and recently tried a new project, 360 degree product photography using a homemade turntable and shooting a product a friend of mine makes, carbon fibre horse saddles.

I had the camera mounted on a very sturdy Benro tripod and used an external shutter release, however on all the tests i did i came across a puzzling problem.

It appears that the mirror (maybe) is moving slightly and altering the vertical postion of the shot, compare the two shots below.

If i looked thru the viewfinder whilst taking the shots i could actually see the movement, it wasn't a 'fast' drop, more a slow 1/4" sec slide down.

Can anyone suggest a reason for this and how to fix it, in the end i post-processed the dozen or so shots that had dropped and aligned them as best i could, the results are here (yes, i forgot to polish the acrylic, but it was just a proof of concept to show my friend).

Gold2

Guessing that the ballhead is slipping slightly. All the weight of the camera is out front and some heads are more prone to slip than others. My MeFoto (aka Benro) will slip more than my Manfrotto if there's a heavy lens on there, so I really need to tighten it up. Mirror slap/camera vibration may initial the movement, but a slow creep just means the heads not tight enough.

I'm not certain I understand what is the point of your question. To me, it appears that the turntable has rotated between these two shots, so it's normal that the saddle moved vertically. It would not move vertically only if the center of rotation was exactly in the middle of the saddle's center. The vertical displacement between shots would not happen either if you were shooting the object at level of the rotating turntable, but then it would move horizontally.

Maybe try centering the saddle... ?

BackdoorHippie said:

Guessing that the ballhead is slipping slightly. All the weight of the camera is out front and some heads are more prone to slip than others. My MeFoto (aka Benro) will slip more than my Manfrotto if there's a heavy lens on there, so I really need to tighten it up. Mirror slap/camera vibration may initial the movement, but a slow creep just means the heads not tight enough.

Click to expand...

Hi BH

No its not head movement (actually its not on a ballhead) - the weird thing is from thge 72 shots for the 360 there were perhaps 10-12 that 'slid' down, and as i was using an external shutter release i wasn't anywhere near the tripod or camera. After the first set of ''slips'' i thought the same, but no everything is as tight as it can get.

As i mentioned in the original post looking thru the viewfinder i can actually see the image slide down, it seemed to happen more the faster i shot, the turntable is moved 1/72 of a revolution by hand using a small piece of stiff plastic and some pins and it prob took me 3 seconds per shot. Everything was shot in manual too inc. focus.

Kev

Marcel said:

I'm not certain I understand what is the point of your question. To me, it appears that the turntable has rotated between these two shots, so it's normal that the saddle moved vertically. It would not move vertically only if the center of rotation was exactly in the middle of the saddle's center. The vertical displacement between shots would not happen either if you were shooting the object at level of the rotating turntable, but then it would move horizontally.

Maybe try centering the saddle... ?

Click to expand...

Hi Marcel

It's not too obvious unless u over lay the two images together in PS or similar.

Below is a split of the two images posted earlier, the body doent move but the image on the right has moved down..

How about lens VR doing something weird on the tripod?

nickt said:

How about lens VR doing something weird on the tripod?

Click to expand...

Hi Nick

Good point, not sure if i remembered to turn off the VR, tho' a drop like that seems a little extreme to be VR related

PhoenixGB said:

Hi Nick

Good point, not sure if i remembered to turn off the VR, tho' a drop like that seems a little extreme to be VR related

Click to expand...

Yeh, I'm not sure, but its on my mind. I just got a Sigma 150-600 and I see a quite large drop when I leave vr on with the tripod. Like you, I would describe it as a slow drop. It happens while I watch.

PhoenixGB said:

Hi Marcel

It's not too obvious unless u over lay the two images together in PS or similar.

Below is a split of the two images posted earlier, the body doent move but the image on the right has moved down..

View attachment 180710

Click to expand...

Now if the image has dropped down it means that the camera went up... I repeat my question: Is the saddle exactly in the middle of the pivot point of the turntable? It's either this or your tripod is not stable enough.

If you just do a simple test, put a white dot on the side of the turntable and one in the middle. Now, take several pictures while you turn the table and you will see the border point going up and down while the middle point should not move.

Either the camera is moving or the turntable. A mirror slap is not going to do that on it's own. You can see in the side-by-side that even the turntable edge isn't lining up in a full circle. Ballhead or otherwise, I'm betting that the head tilt is changing.

Marcel said:

If you just do a simple test, put a white dot on the side of the turntable and one in the middle. Now, take several pictures while you turn the table and you will see the border point going up and down while the middle point should not move.

Click to expand...

Hi Marcel

I understand what u r saying but it isnt that, the turntable is cnetred but not a perfect circle, out of 72shots only 10-12 were lower.

nickt said:

Yeh, I'm not sure, but its on my mind. I just got a Sigma 150-600 and I see a quite large drop when I leave vr on with the tripod. Like you, I would describe it as a slow drop. It happens while I watch.

Click to expand...

Hi Nick

This sounds exactly like the issue i had, u can see the image slowly move down in both the viewfinder and live view. I should have turned off the Vr bit i completely forgot about it and i also used a Sigma lens. Will try it again with VR off.

PhoenixGB said:

Hi Nick

This sounds exactly like the issue i had, u can see the image slowly move down in both the viewfinder and live view. I should have turned off the Vr bit i completely forgot about it and i also used a Sigma lens. Will try it again with VR off.

Click to expand...

I don't recall seeing a shift like that when forgetting to turn off vr/os on my other lenses. Maybe I just wasn't paying attention or maybe Sigma's behave a little differently on a tripod. At 600mm, around 100 feet out, I was shifting about 1 foot off target. Looks like yours is a similar shift for the distance involved. In my OS mode 1, it was a 45 degree slide down to the right, in mode 2 it was just straight down. After hitting maximum shift, it would snap back. I was just pushing my back button focus and observing at that time. Pictures I took did have various amounts of shift. Now that I know what it is, it will end up being a great reminder that I forgot to turn os off when on the tripod.

Hi Nick


Yep i tried it last night and no shifting, my Sigma dosnt have the OS settings but i tried it with and without and got the confirmation - mystery solved - Scooby snacks all round !! :encouragement:

I have only noticed this once before and it was with my sigma lens. While I was shooting it seemed some internal piece of glass was moving. I thought it was build quality of the lens. Never had that problem with any Nikon brand lenses.


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