[Dewman]

I recently bought a pristine copy of a Vivitar 80-200mm Macro Focusing f: 4 lens. ( I managed to remove the flange with ease, thanks to one of the forum member's advice in the lens data base.) Can you please explain the numbers on the macro scale that says: "1:3.4" Does this mean that the image is magnified 3.4 times life size? Is it the equivalent of a rifle scope that is a 3.4X?

Also, what is the difference between a "close-focusing lens" and a true "Macro lens"? Where is the dividing line between the two?

Thanks,
Dewman
Idaho

[ElJamoquio]

There's no absolute definition, though most people think that 1:3 is stretching the limit of 'Macro'.

Your lens will put an image on your sensor at 1/3.4 life size. That is, if you're taking a picture of something 34 mm high, it will be 10mm on the sensor - on Pentax APS-C cameras that would fill about 2/3rds of the frame.

Or in other words, the closest you could get to something would be a frame about 75mm by 50mm, or 3"x2".

So you can't get the eyeballs of bugs very well, but you can certainly get a small bug on a small flower.

[Adam]

1:3.4 is the same as 0.29x, so at the minimum focusing distance your subject would be between 1/4 and 1/3 life-size. 1:1 is considered life-size and offered by most dedicated macro primes. You can go beyond that with tubes, reversal, etc.

[desertscape]

The main difference between a macro lens and one that merely focuses close is the difference in the correction of spherical aberration. Macro lenses are corrected for this at close distances, while non-macro lenses are corrected for it at near infinity distances. Non-macro lenses can be used for macro purposes if you stop them down to reduce the spherical aberration. I do this all the time with success.

[Dewman]

Thanks for all the useful information. Slowly but surely, with your help, this is all beginning to make some sense. By the way, I was very pleased with the extreme sharpness of the Vivitar lens, but the images were very flat and lacked saturation even though I had both increased almost to maximum in the body itself. However, with a lot of PP, I was able to correct this to my satisfaction.

Dewman
Idaho