I am a painter. I took a photo of a painting and noticed that the aspect ratio looked a little off.

[jwt99]

The aspect ratio looked slightly wider in the horizontal and shorter in the vertical aspect.  I turned the painting horizontal and took a photo and it looked correct but when I rotated it to upright in digital photo pro it returned to the slightly wider and shorter than reality aspect ratio.  Any help would be appreciated. I am using a EOS 40D camera.

[jwt99]

ebiggs, Thanks again for mentioning the Perspective Crop Tool.  I was able to watch a tutorial on using it and can see how it will be very helpful.  I practiced just a little on the paintings that I was submitting and can see how it will be valuable in many different situations.  I really appreciate your help.

[ebiggs1]

[Waddizzle]

"These are the same photo taken of the 16X24 painting horizontal and then rotated in DPP clockwise 90Degrees.  It looks slightly wider in her face when vertical as opposed to horizontal. It seems that whether horizontal or vertical the width is slightly exagerrated. "  

You are assuming that your display device has "square pixels".  Many display devices do not have pixels that have the same dimensions in both the horizontal and vertical directions.  I cannot say whether or not a camera LCD has uniform pixels, or not.  But, it should not be regarded as a critically accurate display.

I don't understand what all of the concern about how it "LOOKS" on your monitor, or camera LCD, is all about.  Isn't what really matters is how the images look when printed?  Your camera LCD is not color calibrated, and somehow I doubt if your computer monitor is color calibrated, either.

As for your posted sample shots, I think more care needs to be taken aligning the camera with the subject painting.  Your images are slightly rotated from vertical, and could benefit from an alignment in software.  Misalignment seems to have cut off a portion of the image, too, along the right edge. 

Your shots appear to have been taken with the painting mounted on a stand, or easel, and the camera most likely, I assume, has been mounted on a tripod.  How accurately was the camera leveled on the tripod?  If the camera was leveled, how well placed was the painting?  Was the painting mounted on a vertical plane parallel to the image sensor? 

I would think the best way to take such shots, and to guarantee alignment would be to lay the picture down on a leveled, horzontal surface, and take the picture by shooting straight downward. 

I would recommend using a macro lens for this type of work, to ensure sharpness at the edges.  A conventional lens tends to have curved plane of focus, centered on the image sensor.  A macro lens tends to have a plane of focus that is a flat plane that is parallel to the image sensor, instead one that is curved with the sensor at the center.

A set of macro focusing rails would help you precisely align the camera over the painting.  I use a very inexpensive pair of alignment platforms made by Dot Line.  I have used two of them, stacked crosswise on top of each other.  I would also recommend taking these shots while tethered to a computer, so that you can better see what the camera is seeing.

[EDIT] Do a web search for " Dot Line Camera Platform ".  I purchased a pair of them from B&H.

[ebiggs1]

From your latest post I believe the camera is fine.  It is how you are working that is causing the issue.

It is critical to have everything square and perpendicular to each other. Both the painting and the camera. Neither can be tilted or at an angle.  If either is off you will get distortions when you manipulate it in post.  Like rotating it.

If you have PS why in the work are you using DPP?  PS is far better and will do anything you want done.

BTW, you don't need any special add-ons to do this.  No rails, no special lens.  But I would make sure when you shoot the painting leave plenty of room left around the outside.  That can be cropped away later in PS.  Forget DPP and go straight to PS.

[Waddizzle]

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@ebiggs1 wrote:

From your latest post I believe the camera is fine.  It is how you are working that is causing the issue.

It is critical to have everything square and perpendicular to each other. Both the painting and the camera. Neither can be tilted or at an angle.  If either is off you will get distortions when you manipulate it in post.  Like rotating it.

If you have PS why in the work are you using DPP?  PS is far better and will do anything you want done.

BTW, you don't need any special add-ons to do this.  No rails, no special lens.  But I would make sure when you shoot the painting leave plenty of room left around the outside.  That can be cropped away later in PS.  Forget DPP and go straight to PS.

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I do believe that the OP has already said that they use PS.  I didn't think it would be appropriate to give instructions for PS, instead of DPP4.  I wanted the OP to see that the resolution of the image coming out of the camera is not as important as it may seem.  That you can specify almost any output DPI and resolution that you want in post processing.

I believe a macro lens would most appropriate for this type of photography.  It seems that there is a degree of precision and accuracy involved, and expected, that is most likely beyond the capability of a more conventional lens.  Of course, they could always spend nearly two grand on "the best lens in the world", or spend under one grand on a macro lens. 

BTW, those focusing rails that I mentioned sell for $20 apiece.  It makes lining up stuff easy because you can see the results of what you're doing, as you do it, right on the screen, or vewfinder.  It would be money well spent, for the time saved.

Precisely repositioning a tripod isn't simple, easy, or fun to do.  It takes two hands to move a tripod, which usually means you make an adjustment, then go check it, and then repeat as often as necessary, until you get it aligned.  The same can be said for positioning the painting.  It would be trial and error, until you get it right, or close to right.

[jwt99]

I used the rotation feature in digital image pro.  It was giving me the same aspect ratio as it was giving for the 20X16 paiting when I took a photo of a 24X16 painting.  It did the same thing at least a dozen times.  But when I turned off the camera and waited awhile to take another set of photos of 20X16 and 24X16 paintings it took much closer to correct photos.  So it seems that the camera isn't working properly.  I will send it to Virginia and see what they say.

[jwt99]

300pixels/inch x20 =6000 300X24=7200 16 x 300 =4800  simplified in the file properties 3000 0r 3600 or 2400