Macro Explanation

julie32 · May 25, 2008

Happy Sunday,

I'd like to understand a little more about macro. I've read a lot of posts that a good macro lens for canon is the 100mm 2.8. Can you please explain to me how that is different (the mechanics etc...) than my using my 28-135mm at 100mm? Does a macro lens have to be a prime lens?
Is "macro" basically being able to focus at a much closer range than a "non macro" lens?

As always, appreciate the help so much.
julie

Overread · May 25, 2008

Well true macro shots are where the subject (lets say a bee) is life size (1:1 ratio its called) on the camera sensor - rather than a zoomed in shot.

Now a true macro lens will get you 1:1 (or greater) magnification which is far "closer" than a zoom lens can ever foucs to. Further more the working distance for macro lenses is small - 15-25cm is a rough range of common ranges, with 100mm giving you a shorter working distance than say a 150 or 180mm macro lens. The working distance is essentially the distance that you have to have the lens from the subject when working in the macro mode - so you can see is much closer than you zoom lens.

As for the prime factor - there are some non-prime macro lenses, but they tend to be in the cheaper lens selection and most are not true macro lenses (they let you focus closer, but not to 1:1 ratio). This does mean that its a new set of skills to focus a prime at such a close distance - most people use a focusing rail which attaches between your tripod head and the camera and lets you move the whole camera and lens back and forwards - rather than having to move the tripod all the time.

julie32 · May 25, 2008

overread---fantastic info, thanks so much.

Overread · May 25, 2008

Thanks - out of interest are you looking into getting a macro lens or is it more curiosity at the moment?

julie32 · May 25, 2008

Just got a 5D, so I'm pretty broke at the moment! I would like to get a macro lens, but it may take me a little time to save up. I'm interesting in learning as much as I can about it and dealing with the frustration of not being able to focus as close as I would like to with my other lenses.

Overread · May 25, 2008

I know the feeling of being broke and wanting lenses -- hopfully this summer things should change!
if it helps I recently went thought trying to pick a good macro lens - here is some info:
http://www.thephotoforum.com/forum/showthread.php?t=123319
http://www.juzaforum.com/forum-en/viewtopic.php?f=1&t=1357
http://www.amateurphotographer.co.uk/forums/showflat.php/Cat/0/Number/656062/an/0/page/0#656062
http://www.fredmiranda.com/forum/topic/649103
and one that is not mine
http://photography-on-the.net/forum/showthread.php?t=84105

also:
each as pros and cons, but I can't really find a big con for any lens over the others.
As I see it:
Cannon 100mm - defiantly the most popular lens with good reviews and the fastest auto focusing element of the three. Down side is that it also has the smallest working distance of the three lenses - it also ships without lens hood and tripod collar - the former being an important extra order. However it also, along with shorter working distance, does not blurry the background as well as a longer lens.

Sigma 150mm - good working range combined with good optics and ships with both collar and hood. Some have stated that it has better quality of shots than the sigma 180mm

Sigma 180 - most expensive lens on its own, ships with collar and hood. Often well reviewed with the 2*teleconverter. Has the longest working distance of the three lenses.

I have read quite a few reviews for all the lenses, but so far none of them have had any major drawbacks past focusing speeds - which is not really a primary concern for macro where a lot of work ends up being manual anyway.

Hope this helps! = for the record any of these 3 lenses is (from my findings) a very good choice and any of the three will get 1st class results (after practice of course) - it really comes down to budget and working out what is going to be the best lens for you

julie32 · May 25, 2008

Wow! What's your name, I can't keep calling you Overread!
Very very interesting threads. You sound so knowledgable which is extremely helpful to me.

davebmck · May 25, 2008

This is a good article also. http://www.the-digital-picture.com/Reviews/Canon-EF-100mm-f-2.8-USM-Macro-Lens-Review.aspx
I am planning to get a macro as well. I narrowed it down to the Canon 100mm 2.8 or the Sigma 105mm 2.8. I believe I am going with the Canon. It is about $100 more, but it consistently gets great reviews.

Overread · May 25, 2008

Well I have only been using my camera since christmas - so its a new area for me, but macro is what I have been looking into recently so I have picked up a few things

And shorten my name to OR - most people end up doing it

Joves · May 25, 2008

Now you all made me go into lens lust. I had to go to B&H and figure out what Im getting next. :lol:

Mystwalker · May 25, 2008

You can also use "extension tubes"

Here are some by Kenko ...
http://www.bhphotovideo.com/bnh/con...arch=yes&O=productlist.jsp&A=search&Q=*&bhs=t

Battou · May 26, 2008

Mystwalker said:
You can also use "extension tubes"

Here are some by Kenko ...
http://www.bhphotovideo.com/bnh/con...arch=yes&O=productlist.jsp&A=search&Q=*&bhs=t

Bellows work too.

Does any one make bellows units for modern cameras though?

Mav · May 26, 2008

It's not just the close focusing of macro lenses, but also the flat focusing field too. A lot of lenses have a fair amount of focus field curvature to them which is NOT what you want on a macro lens where you might be trying to fill the frame with an object up close.