I used to think that macro lenses predominantly had shorter minimal focal distances- you get closer to the subject and therefore the subject is larger on the sensor. My 17-85mm lens has a MFD of 35cm and my 75-300mm lens is 150cm. So while my longer lens gives greater magnification, I have to be further from the subject.

The Canon 65mm prime macro lens has a MFD of 34cm- considerably closer than the 85cm of the Canon 85mm non-macro lens and the 45cm of the 50mm prime lens and even closer than my zoom lens.

The Canon 180mm macro lens has a MFD of 48cm. Less than a third of my large zoom lens and a quarter of Canon's 200mm prime lens.

The other thing that I have noted is that both articles and specifications do mention magnification- just about the only time that this is mentioned relating to lenses and I understand that while macro lenses can be used for general photography, they are optimised for close work. Fair enough.

The other thing about macro lenses is that I thought that you bought a macro lens to get the best close up photographs at the most expense but articles that I have read seem to suggest that extension tubes and macro filters are not always used as alternatives to expensive macro lenses but in addition to expensive macro lenses.

I just can't seem to fully get my head around macro lenses and how exactly they are different.

The thing about macro is that it interests me for obvious reasons in that almost anything can be turned into an interesting macro photograph and I would like to give it a go- starting with extension tubes if they are worth considering and moving on to a macro lens at some point in the future.

I think you're overcomplicating things in your head a little! A macro lens is simply a lens that lets you focus on an object closely. I don't think there is an official definition, but generally a macro lens will let you get close enough so that the image projected on the sensor is close to life size (i.e. a 10mm wide object will project a 10mm wide image on the sensor).

If you want to get into macro photography, I would strongly recommend the Sigma 105mm f/2.8 EX-DG Macro, as it only costs about £300 but goes to 1:1 magnification (the size of the image on the sensor compared to the object itself) and has extremely good image quality. It's also a very versatile general-purpose lens when you're not using it for macro work.

I think I mentioned this in another post - extension tubes will allow you to focus closer but will prevent you from focusing on infinity, so with them on the lens isn't as versatile as a dedicated macro lens.

Thanks for that. I would like to think that it wasn't me overcomplicating matters but the articles that I have read.

Although I have been aware of the options- lens reversal, close-up filters, extension tubes, I couldn't seem to find one simple statement along the lines of-

"Macro lenses allow you to get closer to the subject and therefore produce larger images on the film/sensor".

One article seemed to suggest using a macro lens reverse mounted and as noted, I thought that the whole point of a macro lens was to avoid using these alternative accessories/methods.

Thanks also for the lens recommendation.

I dont know about larger but I'm pretty sure a proper macro lens should give you 1:1 reproduction, i.e life size.

Definitely, most dedicated macro lenses should, but as it's not a specifically defined term, several lenses have their closes focusing distances marked as 'macro', like my 300mm lens, even though it's only 0.24x magnification (approx. 1:4).

For something more extreme, you could always try this baby.

Now, what I am seeing there is a macro lens- i.e. one that can get closer than a standard prime lens and what appears to be a built-in magnification element. So as it says, you can achieve higher than 1:1 reproduction "without additional accessories" that very phrase implying that you can (and do) use other pieces of kit for macro photography.

It's not that I have a problem with the basics of what each different accessory does, I just thought that a macro lens was used to eliminate the need for them, but now I begin to see the big picture.

A macro lens is one designed to work most effectively at 1:1 reproduction. A zoom lens with a macro setting is designed to produce a life-size or larger image when printed at 6x4". This means a ratio of around 1:4, which means the optics don't need to be as good.

I've also recently been looking into the macro lens area and have a further question that requires clarification. I'll keep it quite general so lets say there are 3 lenses; 60mm, 95mm and 105mm. All of them offer 1:1 and maximum apeture can be ignored. From what I can work out the main difference is minimum focal length, thus allowing you to be closer to or further away from your subject as required. Is this all that differs, or are there also big differences in viewing angle that should also be considered?

I can never seem to find nice concise answers on the net and trying to absorb the differing information from lots of different websites confusticates me. Probably have more lens questions popping up elsewhere in the near future, so be prepared.

The different focal lengths have varying effects on the final image. Let's say you have three identical coins arranged in a row, near-to-far with respect to the camera. With a wide angle lens, more of the image will be in focus, and the perspective will be enhanced, so that the nearer coin will appear much larger in the image than the further one. As you get longer focal lengths, the depth of field decreases, as does the perspective effect, meaning the coins will appear closer in size to each other.

Very important point nick. In the end I bought the Canon 105mm so that I can get 1:1 (or thereabouts) reproduction without needing to get right on top of a subject such as a butterfly. I didn't actually consider the other aspects- depth of field and aspect ratio, but I am happy enough with the lens although I haven't got too many interesting shots as yet.

Cheers Nick, your explanation made me think of the dolly zoom, and that cleared things up nicely.

From the looks of it for me (UW photography) I would find a 105mm more versatile with regards to getting close to critters without scaring them off and not worrying about scratching a port on coral, but instincts tell me that something shorter gives a more dramatic effect, and some of my intended subjects move no faster than a slug (they are slugs, and of course the others do.)

Is this just a case of personal choice, or is there anything else to consider?

A sample from flickr of the aforementioned canon 1:5 macro.