Being a techie, I have always used a digital device for my photo references when painting.  I can manipulate the image, zoom in, and quickly snap photos of my work-in-progress for comparison.

Here’s what I do before starting any painting. 

Creating a reference folder on iPad/iPhone

STEP 1:

From your main iPad or iPhone screen, click on the Photos Icon to open Photos.

STEP 2:

At the top left of your screen, click on the “+” sign.

Then select New Album.

STEP 3:

Type in the name of your new album (whatever you want) and then select Save.

STEP 4:

Scroll and find your reference photo.

Select it, then click Done.

STEP 5:

That’s it!  You’re done. There is the new folder with your image inside.

Next, let’s crop it.

Cropping your reference

STEP 1:

Inside your new folder, you will see your image.

Click on it to open it.

STEP 2:

Select Edit at the top right of the screen.

STEP 3:

See the 3 icons at the left of the screen?  Click the bottom one that looks like this:

 

 

Drag the four corners of the box until you are happy with its placement. 

Then select Done at the top right of the screen.

 

STEP 1:

Back in your folder, select your (newly cropped) image.  

See that icon in the top right? Click on it.

 

STEP 2:

Select Duplicate.

 

 

STEP 3:

Now you have two!  

Click on the second one to open it.

 

 

STEP 4:

Let’s make that one a B&W image.  

First, click on the top left symbol that looks like a dial.

Then select the Saturation button on the right.
 

STEP 5:

Scroll it down to -100.  You will see your image change as it removes all color information.

 
 When you are happy with your contrast, select Done.

STEP 6:

And there you go!  
Both references side by side.
 
As you work on your painting, you can snap and put your images here in the same folder for easy comparisons.