Mathmatics says that if I have a 50mm lens and use a 50mm extension tube, I will get a 1:1 Macro.
I have a 105mm lens (nikon) that already has 1:1 macro. If I use that same 50mm extension tube, what can I expect as far as magnification factor? I'm guessing that I will go from 1:1 to 1:1.5 is this correct?
EDIT: After reading about reverse lens I tried holding and old 50mm to the end of my 105mm. Here is what I got.
I have the kenko set...with my 105 and the tubes, I'm somewhere near 2:1
With the tubes, the 105 and the 1.4x, It's around 2.9:1
The first number being higher, is higher the magnification by the way, not the other way around. And when calculating what it is for a lens that already goes 1:1, it's a bit different. I don't remember how, I just remember achieving those results from long hours of searching and calculating one lonely night.
If I go out a grab a few tubes for my Nikon 105mm, what kinds of results should I expect? Is it worth it? Will I be able to really get in close for a macro? Do you have any samples?
Thanks,
Kenskid
Originally posted by deapee:
I'm pretty sure it's a good bit more than that.
I have the kenko set...with my 105 and the tubes, I'm somewhere near 2:1
With the tubes, the 105 and the 1.4x, It's around 2.9:1
The first number being higher, is higher the magnification by the way, not the other way around. And when calculating what it is for a lens that already goes 1:1, it's a bit different. I don't remember how, I just remember achieving those results from long hours of searching and calculating one lonely night.
Yeah I think it's worth it. I mean we're talking the difference between taking a picture of a wasp on a flower at 1:1...
and getting down and dirty...this guy here is on the tip of a long blade of grass..I mean he's tiny.
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Once you throw the tubes on, you'll have to be really close to your subject, and that's where the 1.4 teleconverter comes in handy...you can either multiply directly your magnification by 1.4x at the same distance, or you can gain that 1.4x in working distance. so if you were 3 inches away, you can now be 5 inches or something like that...and a few inches is a big difference. Obviously my lighting sucks hehe... here's a few more at or above 2:1
There was this one lady over there on pbase that was just spectacular with macro shots...and she listed her setup for every shot. I've lost the favorite, but if you search long enough, you'll see her gallery, no doubt about it...and you'll know it when you find it.
You are correct in that 50mm of extension will give you 1:1 (focused at infinity). Extension is not that great for extreme magnifications unless you are using specialized very short macro lenses as it takes the focal length equivalent length to get to 1:1. Most 35mm wide-angle primes don't have the flat field properties for macro work as the corners suffer due to field curvature. Also working distance drastically decreases.
Reversing a lens is just like adding a close up filter except reversed lens is much stronger. Magnification = camera mounted lens / reversed lens, so a 50mm lens reversed on a 100mm lens equals 2x magnification. The best part of revered lenses is that for a given magnification working distance is further than most other means of magnification. I find that enlarger lenses work exceptionally well for this since they don't have focus mounts and are flat field lenses.
