Focal Lengths
What’s the difference between a 60mm macro lens and a 100mm one ?
Well the answer is how close to the subject you need to be to focus at 1:1, essentially that’s the minimum working distance on the lens, so with a 60mm lens you need to be closer from the subject to achieve a macro ratio of 1:1 or life size image than a 100mm macro lens. The key factor being with a shorter lens you need to be closer to the subject to get a 1:1 image.
You may wonder why this could be important, well it effects upon your photography use of the lens.
If you are trying to photography an active insect then being further away from the subject will allow you get more shots of it without spooking the creature, and makes it easier to exclude your own shadow from the subject by being further away from it. In butterfly photography many people will use macro lens of 150mm lens and longer to this end. Note however Macro buying lens of this focal length and greater, will greatly impact your wallet!
Just converting from Bridge to DSLR, mostly because I want to try my hand at macro photography, I’ve been combing the web for more information.
Just so you understand my point of reference, I come from those cameras that require you to be like 1 inch away for a good close up, or my last bridge, which had a MFD of 9 inches, a close up was the best you could expect. So for those of us with only that back ground, understanding is a problem.
What about a static setup with a camera and tripod in a studio. Taking equivalent macro shots using different macro techniques, and posting photos showing the setup (I.E. the camera and target from the side showing lens to target distance)? I would like to see what the actual difference is between shooting something 6 inches away with a extension tube vs. say 2 feet away with a long macro lens (just as an example, I don’t know if that is a real world example, or I would not be asking). Seeing reference to MWD and MFD is just a bunch of numbers. What does it mean to use a 50mm with extension tube vs. 100mm macro lens in target distance for the same effect?
Good site, thanks for sharing.
Thanks for the comment Mark.
I’ll look into doing a static setup and posting the shots as a visual reference when time allows. (Hopefully shortly i.e within the next month).
What I can tell you is that adding extension tubes to any lens make the focusing distance shorter. So you’d be focusing much closer with the 50mm lens than its minimum focusing distance. In fact with my 17-40 lens (I don’t have a 50mm) adding the large extension tubes mean you are almost hitting the subject you want to take, so I only need to use the smaller (of 3) extension tubes on flower subjects.
Adding an extension tube to the lens won’t necessarily give you true 1:1 on a lens, it depends on what extension tubes you have and the magnification the existing lens gives you at its closest distance.
Extension tubes tend to be used to enable people without macro lens to get closer to the subject with existing lens. Although you can add them to macro lens to get closer and thereby increase the magnification you get on the lens.