I have begun to use my iPhone's camera for illustrating my Instructables. But, that often means my other hand is busy with something I am trying to show. I always worry about dropping the iPhone and breaking the screen. I decided to make a grip for holding the phone with one hand so that my index finger lines up with the shutter release button on the screen. (For now I am using rubber bands to hold the phone on the grip, but see the 2nd photo in the last step for what I did to replace the rubber bands. The phone shown belongs to my wife. I am using my phone with one hand to take these photos.)

Materials

2 x 4 (wood)
1/2 to 3/4 inch pine 2 1/2 inches wide
1/2 inch dowel
glue

Tools

Square
Protractor and bevel guide
Hand saw for wood
Spokeshave or hand plane
Belt or drum sander
Drill

Step 1: Grasp the 2 X 4 As Shown

Mark around your hand as you grasp a 2 x 4. Saw out a rectangular piece. This will be the part gripped by the hand when using the camera holder.

Step 2: Shape the Wood Block

The wood block you sawed from the 2 x 4 needs to be shaped to fit the contours of your hand. This will provide a more secure grip and less fatigue while using the camera holder. I started with a spokeshave, but switched to light cuts with a hand plane.

When you are satisfied with the shape of the wood block, sand rough marks away with a belt or drum sander.

Step 3: Round for Your Thumb

Your thumb needs to wrap around one corner of the wood block. Round the corner where your thumb will be. (See the text box on the photo.)

Step 4: Drill a Hole for the Dowel

I had only a 1/2 inch dowel. I drilled a 1/2 inch hole in the wood block shaped to fit my hand. The hole is drilled at a compound angle. The dowel slants to the right as seen in the photo by 16 degrees. The dowel also slants toward the viewer at 5 degrees. You may vary these angles according to what fits your hand.

Step 5: Drill for the Dowel

The phone will rest on a piece of pine about 3/4 inch thick. I had some that is 9/16 inch thick. The drill is shown coming through the bottom of the flat piece on which the phone will rest. A drill press would work. I used a table and pushed the wood into the spinning bit mounted on my radial arm saw.

Step 6: Do Not Block the Lens

A corner will have to be removed from the flat piece so the image can reach the camera lens. I drilled a 3/4 inch hole to make a nice radius. In order to prevent chipping out, I drilled the hole part of the way through from one side. As soon as the point of the bit came through the wood, I finished it from the other side. Then I sawed out to the edges. See the next step.

Step 7: Round Corners and Dry Fit

I sanded the corners round. I inserted the dowel and dry fitted the pieces to determine how much each needed to be rotated in relation to the others. I made pencil marks so I could get the right angles again after applying wood glue to the dowel and the holes. Do not forget to mark the dowel in relation to the wood block grip, too. The goal is for the index finger to find the spot where the shutter button will be and do so in a very natural way without strain.

Step 8: Glue

When I drilled the hole in step 5 there was a little chatter on the bit and the hole is a little oversize. So, I squeezed the flat piece in a vise to make a tighter glue joint.

This photo is from the underside of the camera holder, but it gives a view of how the compound angles work.

Step 9: Grasp the Phone Holder

Wrap the hand around the hand grip. The dowel will be against the 2nd or middle finger. The thumb will press from the end of the formed wood block to keep the dowel against the 2nd finger. The 3rd, 4th, and 5th fingers will hold the the wood block grip firmly. You should be able to operate the shutter button on the screen with the index or 1st finger very smoothly without jerking the phone. (Sometimes my thumb is more comfortable under the bottom of the formed wood block than pressing against the end of the wood block. Do whatever is comfortable and holds the phone steady.)

This is designed to work comfortably when photographing objects on a table top. It can be used in other postures, but is not quite as comfortable. Now I can operate my phone's camera with one hand and not feel like the phone might slip out of my hand.

I did replace the rubber bands with pieces of aluminum. A wing nut allows removal and installation of the phone on the grip. See the 2nd photo. The text box indicates the screw on the other aluminum tab. My phone has a rubber "soft" case the aluminum tabs are able to grasp quite well.

UPDATE: I appreciate the comments by DarkTherapy. The earbud cable has a microphone on it with an up/down volume control button built into the microphone. Plug in the cable and press the up button to fire the camera shutter. This is a way of achieving a vibration free shutter release. He suggests making a pistol grip for the iPhone and placing the microphone portion of the earbud cable where it can be pressed easily. Dedicated shutter release cables for the iPhone are also available at this link and other places. (You would need to make certain part of the cable did not dangle in front of the camera lens and "ruin" the picture.)