Tamron 90mm for really close macro work

[Jenny]

Hi,

Happy New Year. I'm hoping someone in this group can help me with a
basic macro photography question. I'm not new to photography but have
never done macro work before, but got the new Tamron 90mm f/2.8 macro
lens for Christmas, as I've always wanted to get those really close up
shots of bugs etc!

I asked the salesperson if this was the lens i would need to get a
closeup of a fly's eye for example and he said definitely. However
when I started playing around with it and found that the closest you
can get to the object is 20cm I don't know how this can be possible.
Do I need additional macro equipment such as bellows etc to do this
type of work? or have I just got the wrong lens for the job?

Any assistance with this query would be greatly appreciated.

Jenny

[Chris Sprague]

Well consider this:

The Tamron lens, which I also own (for Nikon AF) has a maximum
magnification of 1:1. What that means is that if you shoot with
maximum extension, the size of the subject on the film will be the
exact same size it is in real life. Were you to take a picture of a
flower, for example, and later hold the slide next to the flower, they
could perfectly overlap, size-wise.

Of course, 35mm film is always enlarged, either for printing or
projection, so what you end up with is a large shot of a small object,
revealing detail not visible to the naked eye.

If you want to shoot close-ups of a compound eye, you can do this
unaided, unless you want the image to fill the whole frame. It also
depends on the type of insect. Dragonfly? Sure. You'll see the
compound eye patterns at 1:1. Horsefly? No way.

For refererence, here are two quite awful hand-held 1:1 shots of
insects that I've found in my apartment:

http://betelgeuse.umeqs.maine.edu/chris/details/Centipede1.jpg
http://betelgeuse.umeqs.maine.edu/chris/details/ant.jpg

For the type of photography you seem to be after, you're going to need
extra extension at a minumum. Depending on what type of camera system
you own, this might result in the loss of TTL metering.

For the truly hard-core close-ups (photomicography), one set-up that
I've heard of is mounting a motion picture camera lens backwards at the
end of a macro bellows. John Shaw discusses this technique in his
book, Nature Photography Field Guide. Or perhaps it's in Close-ups in
Nature, I forget which.

Never having done that, however, I can't offer much help other than to
point out that such a technique exists, in hopes that you'll be able to
find out more about it by searching for info on your own.

Hope this helps some.