On 25 Sep 04 at 18:35, Den Wilson wrote: > I thought I'd pass on the following advice from a photographer who > took wonderful images of alpines in the wild. The notes were > originally intended for 35mm SLR cameras but I've found they work > extremely well with digital: > > 1. Try not to photograph in direct sunlight. If direct sunlight is > unavoidable try to choose early morning or late evening. If possible > provide some light shade (but not dappled shade). Strong light will > dilute the natural colour. A diffuser or even an opaque shade can help with this. The trouble with direct sunlight isn't so much the color balance as it is the contrast between shadows and highlights. Diffuse illumination is what you want. Overcast skies work for that reason. However, you have to watch color balance. An overcast sky has a very high color temperature and a pale yellow filter may be beneficial. Morning and evening light tends to be warmer (i.e. lower color temperature), and may need a filter working in the other direction. > 2. Use a macro, zoom or close-up lens unless you want to capture the > plant in habitat. These lenses have a very short depth of focus and > will throw the background out of focus which has the very desirable > effect of sharpening the subject. I'm afraid this advice has been a bit garbled. Generally speaking, short focal length lenses have a greater depth of field than long focal length lenses. Macro lenses for 355mm cameras typically have focal lengths either around 50 mm or in the 90-100 mm range, the latter having the shallower depth of field. But any lens will have a shallower depth of field if you open the aperture up. My very fast Pentax ƒ/1.2 50mm lens will have a much shallower shallow depth of field at ƒ/1.2 than my Pentax ƒ/4 50mm macro lens at ƒ/32. I think what you've written would be better broken into two parts: 2a. Use a purpose-made macro lens, a close-up lens attachment, or a zoom lens with a macro feature for in-habitat plant photography. A true macro lens differs from an ordinary lens of the same focal length in (a) being able to focus at shorter lens-subject distances and (b) having a flat focal surface with very little barrel distortion. True macro lenses tend to have smaller maximum apertures than ordinary lenses of the same focal length, but this is not a hard and fast rule. 2b. Use a wide aperture to give a shallow depth of field, thereby throwing the background out of focus and making the subject seem sharper in contrast. However, a known strategy for wildflower photography is to shoot so that both the subject plant and the background are in focus, the latter giving context to the former. Be aware that cranking down the aperture smaller than about ƒ/8 to get depth of field may cause some loss of sharpness from diffraction effects. > 3. The key to good flower photography is the point of focus. > Remember that anything between your chosen point of focus and the > camera will be blurred, whilst anything beyond your point of focus > will remain clear for a short distance (the depth of focus). With > close-up images it is very important to focus accurately on the > anthers if present. If not, consider focusing on the stigma. It is > usually a mistake to focus deep into the throat of a flower which > will throw the anthers, stigma and outer segments out of focus. No comment here. > 4. Learn to give yourself time to study the image through the > viewfinder before you press the trigger. Make sure your chosen > point of focus is crystal clear. Usually, what you see is what > you get. Oh so true! One of our local folks does a lot of wildflower photography; she pays very close attention to what she sees in the viewfinder, and I am gradually learning to mimic her ways, removing distracting twigs, blades of grass, etc from the scene. You've probably travelled a long way to photograph that plant: don't be in a rush to snap it; take your time. And take several shots while you are at it. > My note: The above was mostly aimed at 'in the field' photography. > It is possible to get good results by using a standard lens and a > background screen but remember that the 'chosen point of focus' rule > and light consideration still applies. The depth of focus will be > much longer. Again, I get the sense of some confusion here. My two Pentax 50mm lenses (the very fast ƒ/1.2 and the slow ƒ/4 macro) will have identical depths of field if set to the same aperture, say ƒ/8. There have been some excellent guidebooks published on macro and closeup photography. Look around for one if you want to get a better grip on your wildflower technique. -- Rodger Whitlock Victoria, British Columbia, Canada Maritime Zone 8, a cool Mediterranean climate on beautiful Vancouver Island