Photo Answers
Flummoxed by f-stops? In a muddle over macro? Send your technique and camera questions to digitalcamera@futurenet.com
Your photo problems solved
I use a telephoto lens to take shots of birds at my feeder through my window. The quality of the images varies – why would this be?
Shooting through glass
QAWithout seeing how you are shooting, Joe, I can only suggest a few things that will help improve the overall quality. While shooting through a window isn’t ideal, it’s not impossible to get good results.
If the glass you are shooting through is good-quality and clean, that’s a strong start. The same applies for the lens you are using: get that lens cleaner out. It’s better to shoot from a darker room, so switch off any lights and screen off any other light sources, such as daylight from another window. You want to stop any chance of internal reflections.
When you shoot, have the lens as close to the window as possible. Shoot straight on, rather than angling the lens, where some distortion may prevent your image from being sharp. Time your sessions so you don’t have light coming straight at you.
Alongside the pigeon photo, taken through my office window, the photo of the lioness with her cub was shot through a windscreen, because in the moment I had no choice; it was either take the shot or miss the moment. Because the screen was clean and I shot through its flattest part, I got an image that shows no obvious degradation.
Your camera meters the reflected light from the scene you are photographing and makes a calculated decision on what it thinks the exposure should be. It will usually give you a perfectly good exposure for the scene, but because it works out the exposure as an average of the different tones it sees, it won’t always be accurate.
The failings in this system are most obvious when you have to photograph
Aa scene at the extremes – either predominantly darker- or lighter-toned. The camera’s meter still reads them as middle grey, and your exposure will be wrong as a result. The exposure for the darker scene will attempt to brighten the photo and the exposure for the brighter scene will try to darken it. This will result in under or overexposed images.
By dialing in some exposure compensation (also known as exposure value – EV), you can override this error really easily. You can use either positive (+) or negative (-) EV in one-third-of-astop increments.
For example, if you are shooting a flower close-up and the tones are light across the frame, the given exposure may be one stop under the perfect exposure. Therefore, if you dial in +1 stop of EV, you will get the correct brightness for the photograph.
Can you explain what exposure compensation actually is? Why do I need to be using it?
DIGITAL CAMERA 87
88
DIGITAL CAMERA
Unless you are shooting for press, where you need to quickly wire a JPEG from a location to a newspaper but want to retain a raw file for later use, I can’t really see the point of capturing both raw and JPEG files at the same time. I think it’s something we’ve all done at some point, but if you are confident about processing your raw files, the JPEGs feel like data you don’t need.
If your camera allows you to capture to two cards at once and you want to do this as a failsafe on an important shoot, just in case one card fails, then I’d suggest you set both cards to capture raw files.
AAs a general rule, it’s best to use the Spot Healing Brush and the Healing Brush to remove small blemishes on a person’s face, but the Clone Tool can also be useful, especially when you have something that needs correcting on a defined edge, where either of the Healing Brush tools can mess up and leave an unsightly smudge.
The Healing Brush does a great job at matching and blending the texture and tone from the area nearby you’ve selected as a match, while the Spot Healing Brush tool does this automatically. This is why it’s faster and simpler to use the Spot Healing Brush for most small mark removal.
I capture raw and JPEG files simultaneously so I have a backup – but I don’t really use the JPEGs any more, so is there any point in shooting this way?
I’m starting to learn Photoshop to touch up portraits. When I want to remove small skin blemishes, should I use the Healing Brush or the Clone Tool?
AReversed mono
It sounds to me like the image has been inverted in Photoshop. To make it work like you’ve described, you need a photo of a dark subject silhouetted against a white sky or similar. Then in Photoshop, go to Image > Adjustment > Invert and what was black will become white, and vice versa.
If there are still traces of colour at that point, simply remove all colour saturation. If you don’t have really contrasting tones, however, the resulting image will look like a black-and-white film negative.
I recently saw an image where it looked like the blacks and whites were reversed. How would it have been done?
ADIGITAL CAMERA 89
90