Thursday, March 19, 2009

Abstract Ink Blots in Water

Camera:Canon EOS Digital Rebel XTi
Exposure: Bulb Mode
Aperture: f/22.0
Focal Length: 50 mm
ISO Speed: 100

Lighting: Vivitar 283 Flash set to 1/16th power.

Materials Needed:
1. Fish Tank - 10 Gallon works well
2. Soft Box large enough to fill the back of the fish tank.
3. Ink (I used old ink jet ink for this) I hear color dye works as well.
4. An external flash
5. Tripod
6. Shutter Release Cable

1. Clean all surfaces of the tank that will be shown in the image. It's easier to take 5 minutes and clean the windows with Windex instead of having to clone out a bunch of water spots and dirt.

2. Setup your tripod and attach your camera. Place something inside the fish tank in the middle to manually compose and focus on. Ensure you have enabled manual focus on your lens.

3. Fill the tank use cold water if possible. This will slow the ink down as it falls to the bottom of the tank. This will allow you to snap more images while saving your ink. You will probably want to use a bucket to fill the tank so you don't have to move your tripod and refocus. You can go ahead and fill it in a bathtub and then place something inside the water to focus on if this works better for your particular environment.

4. Place the soft box behind the fish tank. Make sure placement creates a nice white background for the entire fish tank. You may have to custom make a soft box for these images if your box is not large enough. You can also use a white wall behind the fish tank. If you choose to use a white wall you will need to do more test shots to figure out the proper angle to place your flash at so the light will reflect back from the wall through the fish tank to the lens. Using the wall will require more power since your flash will be further from the wall creating more distance between the lens and the light that is reflected back from the flash. I recommend building a soft box instead if you have the time and materials. There are lots of resources online on soft box designs. I suggest searching google and finding a design that works for your situation.

The Shot
Here comes the tricky part if you have not worked with flashes past your max sync speed. We want to stop the motion of the ink falling. Since a flash generally creates a strong pulse of light that last only 1,000th of a second or fast most cameras can not sync at these high speeds. If you neglect to take this into consideration you will get a black bar across your image from the shutter. To work around this problem you will need to work in the dark; hence the reason for prefocusing your camera.

1. Set your camera to manual mode.
2. Set your aperture to control the amount of light the lens will allow to strike the sensor for that brief period of time the flash is fired. My setup actually could have been improved by using a large soft box and moving the box further from the fish tank. Unfortunately at F22 the flash was still too bright at 1/16th power by a stop. This was acceptable however and due to the fact that I was shooting in raw this can easily be corrected post processing. (Less time spent post processing then designing a new soft box).
3. Set your shutter to bulb mode
4. Use the lowest possible ISO for proper exposer while not driving your flash to hard. I would increase my ISO to compensate if I was using more then 1/2 power on the flash. We want to be able to have fast recycle times on the flash to the less flash you need the better. A battery pack would be of great help but not required.

Now you have everything setup and ready to roll here is the procedure on how to take the pictures. It works easy if you can find a helper but not necessary. I will explain the procedure using two people.

People Setup
1. One person (#1) needs to control the ink going into the tank and triggering the camera. The other person (#2) will trigger the flash manually by hand.

Taking your first image.
1. #1 squirt a small amount of ink into the tank in the middle then open the shutter to the camera.
2. #2 As soon as you hear the shutter open trigger the flash manually.
3. #1 once the flash has been triggered release the shutter cable to close the shutter.
4. #1 check the camera to ensure the image is coming out as expected and make adjustments if necessary.

Once you know you have everything setup correctly you can then proceed to take images in quick secession.

#1 Trigger Shutter
#2 Fire Flash
#1 Close Shutter
#1 Open Shutter
#3 Fire Flash
#1 Close Shutter

Watch the ink as it's falling so you know where to add more ink. Experiment with different amounts of ink and color. This is really a fun project to do and each image will be unique and unrepeatable.

Tip: After you fill the tank with enough ink it will look black. Don't! dump the water yet and start over. Increase your flash power a few stops or two and take some more test shots. Just because it's black doesn't mean crazy stuff isn't happening that you can't see. Try string the black water and firring the flash. YOU WILL BE SURPRISED.

Tip: You probably won't want to use a focal length longer then 50mm on a crop body. Your shutter release cable may not be long enough for your to be able to squirt ink into the tank at the same time unless you have a wireless shutter cable.

Tip: Practice a little with your helper to get timing down good.

Monday, March 2, 2009

How to take pictures of cats & kittens

Camera: Canon EOS Digital Rebel XTi
Exposure: 0.002 sec (1/640)
Aperture: f/4.5
Focal Length: 48 mm
ISO Speed: 800
Exposure Bias:-2/3 EV

Lens: Canon 24-70 F2.8 L

Lighting Setup: 1 Medium sized collasable soft box with a Navy Blue replacement backdrop inserted. 1 500watt hot light about 3 feet from the soft box on the left slightly above pointing down. Be conscious of the background you choose. Shooting a white cat on a white background will be much more diffucult then a black background. It's not impossible but you will have to be aware of this and use a diff rent lighting method unless you are going for a high key shot.

Keep your shutter speeds as fast as possible, sacrifice ISO first, nose will be less obvious in a lighting situation like this. Noise can always be reduced in post processing. Keeping the shutter fast allows you to freeze the movement of the cat. The cat will likely be moving around a lot, you probably won't find yourself using a tripod for work like this. Recomposing is required almost frame by frame and lots of camera movements are needed.

Shoot wide open or a few stops from wide open this will help blur the background and reduce any annoying crinkles in the background fabric. It will make it much easier to clone out mistakes and defects if the background is soft and fuzzy. I find F2.8 - F 4 to be a good range to work in.

Your mileage will vary depending on the temperament of the cat you are working with. Treats work well for holding the cats attention for that split second. An assistant is very useful, they can keep the cat from escaping the softbox, lunging at the camera or clawing at the soft box.

If you chose to use a strobe for lighting be careful. Some animals do not like strobes and find them annoying especially after being placed in a box with a big lens in front of them. I find hot lights work well and allow for easy focusing which is critical. Only work with the cat for a few minutes at a time and reward them often. Don't over heat your cat or stress them out, they will be less likely to cooperate in the future.

Try setting up your lights and softbox and let your cat walk in under it's own power to explore the box. If your cat is really hesitant about getting in the softbox try placing the cats food dish inside the softbox and feed them there for a few days.

I like to shoot in continuous mode for brief bursts. Many times you will catch the cat with the tongue or cross eyed after eating or looking at a treat. This can give the photograph of your cat more excitement and playfulness.