All great comments and ideas. This morning I set up and tried again. Paying special attention to my tripod. I spent more time aligning tripod than I did shooting. What I dis find was when I swung the camera mount into the vertical position (which I always shoot in) it wasn't holding in a 90 degree position. With weight of camera it went beyond 90 by about 2.5-3 degrees. Had to very forcefully lock it in place. The camera has distortion correction on, as suggested above. Also I did back off on filling frame with the painting.
I shot off 15 frames at different focal distances, and arpature settings of f9.5,11 and 13. Im sending pics to my granddaughter to process with photoshop. I'm curious as to if distorted, how much and if that value is less than before.
Again guys thanks alot for your time and suggestions. I respond when she works on the files. She's busy working so I don't expect quick results.
As I said earlier, tomorrow I'll take a series of pics at different settings, align center of lens and more carefully align tripod. I'm in the process of taping a large canvas with center horizontal and vertical lines and running tape around edges. I feel taking photos of that may give me a clearer idea what's causing the distortion than of a painting with little reference other than focus.
Great, I had no idea what to look for in a macro lens. Thank, very much appreciated.
My room is 20' x 20'. Part of it, one corner is my work area for painting which takes up about 8 feet long with a desk that takes up about 3 feet for my paints and brushes. Along that side is my easel. Then on one side running the distance of the room are built in cabinets with a formica top.
In the center of the room I've set up for photography. The wall is where I hang my painting to photograph. Realistically I have almost 20' from that wall and about 16' wide.
Wen I look in view finder or screen mostly, i zoom in to fill as much as i can. Either height or width. When I check top & bottom of screen the top & bottom of painting are horizontal and the vertically they also look good. But in editing when I want to crop any background left thats when diatortion shows up.
All my paintings range from 28" x 36" or larger. Copy stand wouldn't be practical. At this point I'm considering a new macro lens, looking into renting one to see if that fixes this problem. If so then I'll buy one. In the meantime I'll try suggestions posted. Thanks for your input.
My lighting since I bought studio lights has been great. Do place at 45 degree angle and other than some glare from the varnish, which using the polarizing filter has almost totally eliminated in the raw images, I,ve been able to eliminate using the google nik filters.
I,ll try mirror, have to go buy one. See if that helps. If all else fails I look into a macro lens. Thanks for your input.
On a wall. Plus I hang it from the frame so it's flat, not from a wire.
I'll have to read my manual to see if the Nikon has that. Waiting for darkness (ambient light) here to experiment with a painting that I just finished. Am in process of upgrading my software that now has lens correction and other types of corrections (not sure what they are) but hoping that will help. You lost me on your answer but I do know someone working for my grandaughter who uses my camera. Waiting for her to finish working. I thank you for your reply.
Another thought. My paintings are varnished so due to reflective quality I use a polorizing filter. Any chance that could cause distortion?
I don't have photoshop or lightroom but as I posted earlier my grandaughter does. So if she can correct distortion then I'll have to depend on her editing my work. I use a program Serif photoshop x5, which I just checked ans it has no capability for lens distortion.
I do use a tripod that has built in bullseye level but I also check it with another level. I've gone as far as putting a hole in center of lens cap, ran a string through it and then checked all four corners of the painting. Since paintings are hung on a wall, any difference will be from tripod position. I move tripod untill all 4 corners measure the same.
I have a bullseye level on tripod and i use a inclinometer to measure any possible angle from the painting. Any degree difference I then place it on camera to match. I've also moved focus point on camera from middle, moved it to top and bottom to see if focus is same.
After the last point about lens distortion I realized that the quantaray, set at 80mm has somewhat less distortion than the nikon at 55mm. Guessing about half the distortion. Will l try series of photos set at differ focal lengths on both lenses. Thanks for the reply.
Thanks for the reply. I don't have lighroom, but my granddaughter does. I'll send her some images to see if that works. She's a pro with that software.
I suspect that your right about the lens. I invested in studio lighting so I got that covered. In the meantime I'll look into macro lens . Thanks again.