Macro lenses and crop bodies.

[mfostervt]

Hi all.  I have a Canon 70D (and love it).  I bought it for photographing birds and got a 400 5.6 prime lens and couldn't be happier (except I now want a faster lens).  I also like to do macro type photography and have used my Nikon superzoom for this which does pretty well but I know a macro prime lense would be much better.  I have been looking at the Canon EF 180 3.5 macro and the EF 100 f2 lenses as options for me.  I don't quite understand how these lenses interact with the crop sensor.  Will I get true macro photography?  I like to use macro photography for things like flowers and insects in the wild, so wonder if these will work for this and how close would I have to get?  Will they allow me to take a good picture from a bit of a distance.  I find that capturing things like dragonflies keeps me away from the subject by 3-10ft.  Will these lenses work for this?  I am tempted by the the 100mm lens as it offers a f2 stop, which woud make getting photos in less than ideal conditions easier.  I'm open to all suggestions and help. 

Thanks

[TCampbell]

The focal length is true. A 180mm lens looking at a subject 10' away will have a "dimensional" field of view of 1'3" x 10".

A true macro can allow you to focus on a subject so close to the camera that you get a 1:1 scale of the subject on the sensor.

To give you an idea of what that means... a US penny has a diameter of about 19mm. The APS-C size sensor on your 70D measures about 23mm wide by about 15mm tall. That means if you tried to photograph the penny at closest focusing distance, the penny would fit in image the long way with (a couple millimeteres to spare on each side) but it would not fit by height and a few millimeters would be cropped off the top & bottom.)

Canon does make the EF-S 60mm f/2.8 Macro USM specifically for crop-frame bodies, but if you're trying to put more distance between camera lens and subject then you'll probably want a longer focal length lens.

[MikeSowsun]

You mentioned the 100mm 2.0 but that is not a Macro lens. It actually has quite poor magnification compared to most lenses today.

Were you thinking about the 100mm 2.8 USM Macro or the 100mm 2.8L IS Macro?  

If you want to photograph a dragonfly from 3'-10' feet away you will have a problem with any of those lenses as Macro lenses only get "Macro" at close focus distances. Macro lenses don't magically improve magnification at 3-10'. At those distances they will look like any other normal lens.    

If you really need to stay 3-10' away, the 180mm 3.5 Macro might be your best bet but your 400mm with an extension tube might be even better. Extension tubes allow you to reduce the minimum focus distance. Your 400mm has a min focus distance of about 10' and if you can get closer it might act as a pretty good Macro lens.

[mfostervt]

Mike,

Yeah, I meant the 100 mm 2.8 USM lens.  I was reading about the IS and most folks were saying that it was really not needed and doubles the cost of the lens.  Plus, from what I read, the lens is mostly plastic, where the one without is metal.  Maybe I'm getting that mixed up with the 180.  I do like to get photos of insects, and getting close to many is not that hard, so the 180 might be my ticket.  I need to read more about extension tubes.  I have heard about them, but did not realize it allows you to get a closer focus.  I don't know how long the tubes are, but it could really make a long lens LONG which would make a tripod mandatory.  I was kind of hoping I could do some of this photography with either hand held or using my monopod.  I'm still learning, but its all fun.  Thanks so much for your help.  Now I need to research extension tubes.

[TCampbell]

The 180mm is fairly expensive.  

Macro and tripods sort of go hand in hand because the depth of field can be paper thin.  That means if you focus carefully but are hand-holding the camera, and your body sways just a very tiny amount (you lean in or lean out... maybe only by 1/4") that can be enough to completely put your subject out of focus.  Hence tripods.

But if your subject is a bit farther and your depth of field is a bit wider, you might be hand-holding the camera.  In those cases, the IS is nice to have.  

The "L" series version of the 100mm macro has a much higher detail resolving power.  This is plotted via an "MTF" (modulation transfer function) chart (there are articles that explain how this work).  The higher up the lines are on the graph, the better.  But Bryan Carnathan over at the-digital-picture.com (who does insightful reviews of Canon lenses) calls this lens "drool worthy".  

The non "L" version is no slouch itself and probably the more popular lens for those just getting into macro... but when you get the "L" version you're also getting noticeably upgraded optics in addition to the image stabilization.

[mfostervt]

Thank you Tim,

I thought that I had read that the optics were similar between the two 100mm lenses.  Seems that people revewing the lenses are all happy with them regardless of which one.  I will have to look closer at the optics in the link you shared.  I would prefer to go with the better optics and be happy with the lens forever.   I imagine that I will probably upgrade to a full size sensor body at some point and want to only buy lenses that will work with any body I might end up with.

[ebiggs1]

From what you have said, the EF 180mm f/3.5L Macro USM is the lens for you.  However, it may have been discontinued.  You can still find them.  It is a fantasticly sharp lens for anything.  You do have to be very close to your subject to make true macro images.  Otherwise it is simply a 180mm telephoto.

The is no practical difference considering a f2.8 to a f3.5 lens.  The margin is minor at best.  I really love this lens and you will too.

Becareful if you try to use ectension tubes on your EF 400mm f5.6.  The entire focus range of the lens is altered not just the close focus.  Trying to get fast or even slowly moving subject in focus will become a challenge.

Barring that recommendation, you should get the EF 100mm f/2.8L Macro IS USM.  I love this lens too!  It is head and shoulders above the rest of the Canon macro lens line (besides the 180mm that is).

IMHO, of course and worth every penny.

[TCampbell]

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@ebiggs1 wrote:

From what you have said, the EF 180mm f/3.5L Macro USM is the lens for you.  However, it may have been discontinued.  

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Hmm... I haven't heard anything about these being discontinued.  You can still find them sold at all the "usual suspects" (B&H, Adorama, Amazon).  

I did check the rumor sites --  nothing about them being discontinued but I DID find something that showed Canon took out patents on an IS version of the lens as well as a DO version of the lens.  But Canon takes out lots of lens patents for lenses that may never see the light of day -- so that doesn't necessarily mean they'll release one, but it does mean they went through all the effort to at least look into, do some design work, and possibly prototype it.  

That implies that a replacement is at least under serious consideration.  Of course this same sort of rumor came out about the replacement of the 100-400mm zoom a LONG time ago (I think dinosaurs still roamed the world then that rumor started.)  And they've only recently got around to releasing that update.  So if you're waiting for a new lens... you could be waiting a LONG time.

[ebiggs1]

"So if you're waiting for a new lens... you could be waiting a LONG time."

You are so right!   With Canon anyways, if want a lens go buy it and don't wait for the next version. 

I have not seen a formal announcement of it being discontinued and certainly there is a supply out there but I believe the Canon web site claims it is out of stock.  A indication there won't be any more.  I haven't checked lately but that was the case a while ago.

It is a great lens as is.  I just don't do enough macro to keep a 180mm f3.5 tele around or even the 100mm f2.8, so it may be get sold, too.  I keep getting told I have too many gear downstairs any way.