The theory behind this approach is, first, that a tripod might get in the way of other patrons of whatever public space is involved. However, with handheld shots, one may need a much faster shutter speed to avoid camera shake. That translates, in turn, to a higher ISO in some cases to establish the desired depth of field called for by the composition. Finally, using a telephoto gives you the opportunity to capture shots further away than would be available with a macro lens, which is generally limited to very tight closeups.
I have a (mediocre) 70-300 mm telephoto lens, and my camera does allow me to set a combination of ranges for shutter speed and ISO and the camera then does the calculations to establish the proper overall exposure. So I decided to give the technique a try on my next visit to the Mitchell Park Domes. This was my experience.
First, I soon found myself looking for photo opportunities that were further off the paths that run through the botanical domes than I had been looking in the past. This was the biggest advantage of this approach. On the other hand, there were also disadvantages. One was that my telephoto lens is more limited in its largest aperture setting than is my macro lens. In short, the telephoto is not as "fast" as my macro, and as a result I needed to increase the ISO more than would have been the case with my macro. Compounding this issue was the fact that, because everything was handheld, I had to keep the shutter speed relatively fast, and this also required raising the ISO rating. As a result of all this, there was a lot more ISO "noise" in the shots I got than would have been the case with my macro, though this noise is hard to detect at the resolution I use for the blog. Moreover, I "cheated" a bit on the shutter speed and some (actually quite a few) of the shots evidenced camera shake. Finally, my macro simply has better resolution than does my telephoto, and so the shots I got weren't quite as crisp as I would have gotten with my macro.
OK, so what did I get? As anyone knows who has visited the domes, there is a show dome, a desert dome, and a tropical dome. In the show dome spring floral displays were in prominence (something that is a long way off still for anything growing in the great outdoors). That included a profusion of easter lilies. In this case I decided to take a shot of the backs of a couple of blossoms.
Not bad, actually, and at an aperture of f/5.6, I was able to isolate the flowers adequately from the background. Technically, this was one of the better shots.
And here is a shot of a multi-colored tulip (as well as others).
In this case, even with the lens at a wide-open f/4.5, I felt the background was too distracting. Just too many flowers. However, this tulip was several feet off the path, and I never would have considered shooting it with my macro.
I took the following shot in the Desert Dome of a tangle of vines (or whatever).
Not exactly a macro shot, considering the size of the vines, but again I would not have taken this shot, which is at least mildly interesting I think, if I had only had my macro.
On the other hand, I have taken the following shot any number of times.
I found out I had to keep backing up to get this shot in focus, as the minimum focal distance for the telephoto lens is just under five feet (compared with a minimum focal distance of under three inches for my macro). This was shot with the lens at f/5.6, which was plenty to blur out the background.
And here is a shot in black & white of a desert plant that was probably 35 feet away and that I never could have gotten with my macro.
I just liked contrast between the spikes that are projecting toward the camera and the vertical spikes serving as background.
Then it was on to the Tropical Dome. The following banana leaf simply would not have been available with my macro--too far away. On the other hand, the image is not as crisp as it could have been, due mostly to camera shake.
Nor would I have taken the following shot which was essentially a vertical shot of the top of one of the tropical trees in the dome.
I liked the following shot of interwoven ferns. This was probably my favorite shot of the series, and frankly could have been taken with my macro and tripod.
And here is shot of a tropical leaf that I liked because of the way it was opening up.
Finally, I intended the following shot all along as an abstract.
I set it up with a wide open lens at f/5.6 focused on the front edge of one of the leaves. This allowed everything else to go out of focus, creating the soft image I was seeking. I felt I had to establish at least one point of focus to prevent the entire photo from looking like just a poorly focused shot. I think it worked.
I'm not sure I am going to repeat this experiment. If I do, I will bring along my tripod to improve the technical quality of the shots.