MattMatt said:
Hi Jay,
I would like to know what the technical difference is between the different focus modes. I have not been able to find this information on the web, and it seems that all the digiscopers choose their settings by trial and error.
What is "macro capability"? I don't know too much about cameras, but it seems to me that either something is in focus or it is not. Why would the camera have a setting that does not focus as well as it can? What does it do differently in macro and normal mode?
--Matt
Technically, macro photography is imaging where the image on the film (or CCD) is the same size as the subject or up to 10 times the size of the subject. Higher magnifications are micro photography and lower magnifications would be close-up or normal photography.
But the term is generally used in marketing to mean close-up photography. The CP4500 probably comes very close to achieving a true macro mode, which is quite an achievement considering the CCD is only about 9mm across the diagonal.
I suppose that Adey has pretty much got it right about why there are different focusing modes. By limiting the focus "search" range, the camera can find focus more quickly if its mode matches the subject distance.
I'm pretty sure that the macro setting gives the largest range and hence the longest focus times. This may sound counterproductive, but I suspect that it actually is a benefit. If the camera cannot find focus, then you must refocus the scope a tad. Then you can retry the camera focus. This is surely slower than letting the camera find the focus. Though I suppose that if you were in a fairly controlled situation - like camped out in a hide and observing a specific nest - that not using macro could have an advantage in finding focus more quickly. But in practice, once you've prefocused, minor focus shifts tend to be found pretty quickly.
In the end, I suspect the real advantage to macro and the yellow flower is that keeping it in the "yellow flower" range means you don't use too much camera zoom.
Yes, trial and error is the way of digiscoping. Scopes and eyepieces were not designed with digiscoping in mind. So we must do a lot of the R & D. But many have gone before us and blazed the trail, so there are some pretty tried and true techniques and you don't have to start entirely from scratch - unless you want to. And its not all trial and error. The collective experience and some technical understanding can help us to narrow down those things that are more likely to yield good results. The general advise to see the "yellow flower" is one of those bits of tried and true wisdom. Its not necessary to be in this range, but being there improves your odds of getting good results by narrowing down some of the variables.