View Full Version : Changing Aspect Ratio From Photo Reference to Support - x-posted Composition and Desi

02-17-2019, 08:55 PM
I like to take my own reference photos. My printer only prints them as 8x10. If I am going to paint 8x10 or 16x 20, then scaling is not a problem because the aspect ratio is unchanged. But what if I want to paint on an 11x14 support or 9x12? I bought mattes cut to various inside openings, such as 5-1/2 x 7 and 4-1/2 by 6, and I can use them to crop an 8x10 photo to the desired aspect ratio, but when I do that I have to crop so much of the photo that important elements of the composition get cropped out. There must be another way. How do you handle changing aspect ratios from a photo to your support? I think I'm missing something obvious. Thank you for your thoughts.

02-17-2019, 10:34 PM
There is no way to change the aspect ratio of your images without losing some of the image area. To get the largest possible print on an 8 1/2 x 11 or 8 1/2 x 14 piece of paper, crop it to the exact ratio first in your photo editing program then print it at maximum size allowed for your printer without loss of image area.

Here is how you do that in Gimp (https://www.itproportal.com/2014/07/16/how-to-resize-an-image-in-gimp/)

If you don't use Gimp, search "maintaining aspect ratio when cropping" for whatever photo editor you are using.

02-18-2019, 03:43 AM
This is how I expand drawings for theatrical back drops and flats.
Draw a diagonal from one bottom corner to the opposite upper corner on your reference.
Measure this angle with a protractor or pick it up with a bevel square.
Project this angle from the bottom corner on the support to where it meets the top or the side.
You can now form the rectangle from that point.
You will now have an extra strip either at the top or bottom, itís easy to decide what to do with that extra space put it at the top or bottom left or right or split it.
To form the grids on the reference and support put in a second diagonal across the corners. At the intersection erect horizontal and vertical lines, you now have four squares.
Keep dividing these new squares with diagonals till you have formed grids of sufficient size to transfer the detail.
It depends on the set designer and director how close to the drawings we need to be, often there is no need to do elaborate grids and things are just quickly drawn in freehand.
Donít forget to leave room for your art, a good director always allows for that.


02-18-2019, 08:13 AM
I would take your reference photo with extra room around the edges. Then crop the photo on the computer to match the painting aspect ratio of your painting.

Depending on what type of camera you have, the aspect ratio may be changeable. Not sure what aspect ratio your camera is, but most DSLRs have a 3:2 ratio, with Micro 4/3rds cameras having a 4:3 ratio. Many higher end camera let you change the aspect ratio. Almost no camera has a 4:5 ratio to print the same ratio at 8X10. Are you sure you can't print at the same ration that the photo is? That would solve a lot of your issues. My camera's default ratio is 3:2, so when I print, they are sized at the same ratio, so my prints are 9 x 6 or 10 x 6.66.

Hope this helps,


02-18-2019, 08:26 AM
I find it helpful if the ratio of my reference photo matches my painting surface exactly. Trying to paint a 3:4 ratio painting from a 2:5 ratio photo usually presents compositional problems I would prefer to be solved in cropping the photo.

If you always paint in certain aspect ratios, the advice given of matching your camera's aspect ratio as closely as possible to the painting's can help quite a bit in making composition decisions in the camera. Another thing that can be helpful with cropping later is to remember to take at least one photo of the scene with the lens zoomed out wider than needed so you will have room to crop it exactly the way you want. The closer shots can be used for discerning details.

I rarely use printed photos to paint from so this is not an issue for me. I paint from images cropped to match the panel aspect ratio, displayed on a high quality monitor. Being able to view source images zoomed in or out and at actual size on the monitor plus adjusting hues and values can be quite helpful as well, not to mention the savings on ink and paper of not having to print anything.

02-18-2019, 01:48 PM
The aspect ratio itself isn't the most important thing to start with if you're looking for good composition. What I often do is open the photo image in a graphics program and use the cropping tool to determine what aspect ratio works best. I often do several test crops (portrait, landscape view, square, etc. and different variations) and then decide which is best among them. Make sure to save an original copy of your photo someplace that you don't use for cropping so that you don't goof and lose it.

As an aid to finding the best composition, I was given another good method for using photos by an instructor of mine who is also a well known painter and expert in painting landscapes (he literally wrote the book). He had us cut out two "L" shapes out of cardboard; each had a edge in each direction of at least 12". The way to work with them is to print a photo of your scene, in color, ideally on photo paper, but inkjet will work too, at a fairly large size (8x10 is probably best, but you could work with smaller sizes if you need to). Then lay the two "L"s on opposite sides of the photo so that they form a rectangle in the center. You can then move them around in order to find the best composition. Once you've found it, the best thing would be to paint on a surface that maintains the same proportions. But that's not always possible, so select the canvas size that's closest to the aspect ratio of the composition, and adjust the ratio of the composition just slightly if necessary.

Using either of these methods, you're making decisions based on what's most important for your painting. Note that I also take several photos of the same scene so that I can select the best one to crop to create my final image.

EDIT: The advice that contumacious offered to take a zoomed out larger view of the scene rather than actually try to crop with the camera is another good idea. Some of this may depend on what kind of painting you do too.

02-18-2019, 02:08 PM
A 10 x 8 Inch resized to 7 x 5.5 inches works out as 7 x 5.6 inches. So your losing 1/10th of an inch on the height
That will NOT affect the composition.

A 10 x8 inch resized to 6 x 4.5 inches works out as 6 x 4.8inches. So your losing about 1\3 of an inch on the height which may affect your composition SLIGHTLY being so small.

Note above applies to landscape so swap height for width for portrait.

02-18-2019, 04:39 PM
Thank you for your comments. They are very helpful to me. I don't have Photoshop and am trying not to get it, because I work with a computer all day, and would prefer not to spend much time on the computer while doing my art hobby. I think taking wide shots to go along with my closer up shots is a good idea, as is continuing to use my mattes that are cut to various aspect ratios. I think using the mattes works out about the same as using the L-shaped cardboards, although the L-Shapes are infinitely variable, so maybe I'll give those a try.

02-18-2019, 08:44 PM
I tried the L-shaped pieces on a zoomed out photo of the zoomed in photo that was giving me trouble. I got it the way I want it, added a half-inch to each side to get to a standard aspect ratio, and then did some more cropping and ended up (tentatively) with a square composition. Thank you, I really appreciate the suggestions. This seems to be a more flexible approach than my mattes. I never would have seen this with my square matte because it would have cut off too much.

02-19-2019, 09:44 AM
I take photographs with my iPhone or digital camera. I then edit the photos on my iPad or iMac to achieve the proportions I want for my paintings. I do this mainly through cropping, and can adjust the proportions to virtually any size canvas without altering the aspect ratio. Often, cropping a photo will achieve a much better composition than the original shot. If you want to keep the original photo unchanged, you can simply duplicate it and use the copy for cropping.