(by Mary Olivera)
This covers steps to take a picture with your iPhone and then size it properly with a Mac computer. This may seem daunting at first, but is actually easy once you see the different screens. 
1. Take a picture of your painting using your iPhone.

  • a. Take care to square the painting with the edges of the camera lens, as well as possible.
    • i. If your photo is not square, you can correct it later on but, it’s easier if you get it right from the beginning.
  • b. If your picture is a horizontal picture, take the photo horizontally. If it’s a vertical, take the picture vertically.
  • c. It’s a good idea to take two (or more) photos of your picture to choose the best one. 

2. Crop your picture.

  • a. On your iPhone and looking at your picture, press Edit.
  • b. Press the Crop tool to straighten and crop the image.
    • i. Move the scale marker to straighten the image, if needed.
    • ii. There is a box around the image with white corners. Put your finger on and drag the edges up to your painting image.
  • c. If the crop is a good representation of your painting, press Done. 

3. Move your edited picture to your Mac. There are two ways to do this:

  • a. Email it to yourself. To do this, “Select” the photo, choose “Mail,” fill out the Address and Subject, press “Send” and then press “Actual Size.” I
    • . Be sure to email at “Actual Size” for the best resolution.
    • ii. Open the email on your Mac and select to view the image in the Preview app.
  • b. If using iCloud, the image is already added to your Photos Mac app. Open the Photos app (colorful flower in your Launchpad or taskbar list at bottom of your Mac screen). 


1. On your Mac, locate and select your image by double-clicking it. It will open in the Photos app.
2. Edit your photo.

  •  a. On some Macs:
    • i. From the Photos Menu Bar across the top of your computer screen, click on “Image”, “Edit With,” then “Preview.”

  • ii. You will get a new copy of your photo and see the “Preview” menu bar across the top of your screen. 

  • b. If your Mac doesn’t have the menu options shown in step 2-a, skip the step above. Just open your image in Preview to continue.
    • i. From the Preview menu bar, select “Tools” then “Adjust Size.”
    • ii. You will see a pop-up screen with image dimensions.


iii. Resize your image: 1. The “Resolution” box shows 72 pixels/inch. Change 72 to 300 (or whatever Resolution is specified for that show).  Click “Ok.”

    • iv. Again, click on “Tools,” then “Adjust Size.” Now look at the Width and Height.
    • v. Choose the longest side (the largest number). Change the largest number to 3000 (or whatever the show specs say). Click “Ok”.
    • vi. Select “File” and “Save”. This has now resized your 72 dpi phone image to the correct specs for submission. Wow!!!  

9. Do this for each of your art photos. You are ready to go to the website and enter the show. Be sure to choose your edited art photo during the submission process. 

Copyright Central Texas Pastel Society. All Rights Reserved.

Photo Editing using iPhone: Exhibit Quality Results