macro lens or extension tubes? - DPChallenge Forums

12/30/2007 09:17:32 PM · #1

I was thinking of getting a macro lens (canon 100 2.8) but a friend said he finds he uses his extension tubes more and likes them better. They are cheaper...(kenko tubes). Since this is for fun and the occasional wedding ring shot, any thoughts on what is the better way to go?

Kenko says their tubes won't work on EF-S lenses so I could use the tubes on 28 1.8, 50 1.2, 85 1.8, 135. 28 or 70-200 2.8.

What kind of magnification can I expect to get (is there a formula for this?)
What about distance to the subject on a tube vs 100 2.8?
What about F32 - the 100 2.8 does it, the other lenses generally stop at F22.
What about loss of light - the tubes can cost a stop or 2 or ?? of light...how much light loss?

12/30/2007 09:53:17 PM · #2

With the lens focused to infinity, the magnification is TL/FL where TL is tube length and FL is the lens focal length. So for 50mm of tube length with a 50mm lens, you get life size, but you'll need 100mm of tube length with a 100mm lens.
What happens when the lens is *not* focused to infinity is dependent on the design of the lens (whether it's an internal-focus design or not). You will always get slightly more magnification when focused closer than infinity.
For the same focal length and magnification, the working distance will be approximately the same, whether you're using tubes or a macro lens of the same focal length as your lens. That said, the 100mm macro lens has an interesting optical design; the focal length actually changes as it's focused close; it ends up at about 90mm at closest focus if I recall.
As far as f-stops, yes, the 100/2.8 goes to f/32, and if you absolutely must go there for DoF, then you must, but softening from diffraction will be quite noticeable.
Your light loss will be the same whether you're using a macro lens or tubes. If you double the magnification, you lose two stops, because the area is quadrupled (same light over four times the area is two stops loss).

Tamron SP AF 28-75mm f/2.8 XR Di for Canon

12/30/2007 10:42:36 PM · #3

Originally posted by kirbic:

Your light loss will be the same whether you're using a macro lens or tubes. If you double the magnification, you lose two stops, because the area is quadrupled (same light over four times the area is two stops loss).

Got most of what you said, but i quoted the above cause I don't get it at all...

Example time...

I have a 50mm lens and a marble on my desk. I can focus at 1 foot, 1/30th at F5.6 and take a shot. Marble too small...I add extension tubes (say 50mm) to get 1:1 life size.

Do I have to move closer to get focus and that 1:1 life size bit? How close?
Do I have to change the exposure?

SamDoe1

Canon EOS-350D Rebel XT

12/30/2007 10:52:05 PM · #4

Originally posted by Prof_Fate:

Do I have to move closer to get focus and that 1:1 life size bit? How close?
Do I have to change the exposure?

Set the lens to infinity, move back and forth till it's in focus.

Yes you'll have to change your exposure, but metering should work.

12/30/2007 11:10:39 PM · #5

Originally posted by Prof_Fate:

Do I have to move closer to get focus and that 1:1 life size bit? How close?

Yes, you do. About as close as if you were using a 50mm macro lens, although the exact working distance depends on the lens design.

Originally posted by Prof_Fate:

Do I have to change the exposure?

Yes, you will. As Sameer posted, metering still works, just realize that you will lose light.

MelonMusketeer

Nikon D7000

Nikon MF 50mm f/1.4

12/30/2007 11:53:41 PM · #6

I use a 55mm Micro Nikkor a lot, and like that I can hand hold it for a lot of macro shots. Camera shake is a problem when I use an extension tube with a 100 or 180mm lens unless I use a tripod or have a lot of light. What I am saying is that I can hand hold, and I like the working distance of 6 to 12 inches with the 55mm for small objects that will not fly away. I do use the longer lenses and tubes with a monpod in daylight for small critters and plants because I like the way the images look.
Have you thought about a reversing ring for the 50mm?

Message edited by author 2007-12-30 23:55:45.

Canon EF 16-35mm f/2.8L USM

12/31/2007 09:12:59 AM · #7

I tried a reversing ring and didn't like the results, the weight/balance of the deal.

I like the versatility the tubes will give me compared to a 100 macro is just that and nothing else. But I've used a 100 macro a few times when out with friends that have them and know what it can do/how it works.

hopper

Canon EOS-80D

Canon EF 35mm f/2 IS USM

12/31/2007 09:30:07 AM · #8

the downside to tubes is having to remove them if a non-macro shot presents itself while you're shooting

Message edited by author 2007-12-31 09:30:22.

trevytrev

Canon EOS-5D

12/31/2007 09:54:04 AM · #9

Originally posted by Prof_Fate:

I'll disagree with the versatility comment. I own both the canon 100 f2.8 and extension tubes and find the macro lens by itself very versatile. It can be used as a portrait lens, though a bit on the long side on a crop sensor, or a medium telephoto lens. Throw in that it is one of the sharpest non L lenses, has a apature of f/2.8 and does macro work and I think it is probably one of the best all around lenses one could own. If you put tubes on a lens you are pretty much stuck doing macro work unless you take them off. When you buy the canon 100 f/2.8 you are getting a lens that will do much more than macro work. jmo, Trevor~

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Nikon

12/31/2007 10:50:39 AM · #10

I ordered the tubes. I considered all the possibilieis, and went with the cheaper, more versatile option (i think).

I also ordered a timer remote to play with, and a lensbaby.

Thanks for all your advice!

Message edited by author 2007-12-31 10:50:52.

MelonMusketeer

Nikon D7000

Nikon MF 50mm f/1.4

12/31/2007 12:07:37 PM · #11

I see in your profile that you have several great cameras, so when you are using the extension tube on one, you can have another set up handy to shoot the normal shots.
Another thing about the tubes is that you can use them with several lenses. If the ext tubes will get you thru until the opportunity comes up to get a great price on a good macro lens, I would get one.

levyj413

Apple iPhone 15 Pro Max

12/31/2007 12:55:35 PM · #12

Originally posted by kirbic:

With the lens focused to infinity, the magnification is TL/FL where TL is tube length and FL is the lens focal length.

Here's an example, where with 68mm of tubes on a 50mm lens, I get about 1.4:1.

One important thing to note is that this is with a 50mm prime. I don't get nearly the magnification on my 17-50 at 50mm.

Message edited by author 2007-12-31 12:56:40.

12/31/2007 01:25:24 PM · #13

Originally posted by levyj413:

Originally posted by kirbic:
With the lens focused to infinity, the magnification is TL/FL where TL is tube length and FL is the lens focal length.

Here's an example, where with 68mm of tubes on a 50mm lens, I get about 1.4:1.

One important thing to note is that this is with a 50mm prime. I don't get nearly the magnification on my 17-50 at 50mm.

I thought from what I've read here and elsewhere, that more stacking more MM of tubes than MM of focal length is not possible. So how did you get 68mm of tubes on 50mm of lens?

I know that listed amongst the specs of lenses is the 'magnification' factor. For instance, the Nikon 50 1.4 lists magnification at 1:6.8 where as the Tamron 17-50 2.8 lists it's magnification at 1:4.5, giving the 'native' magnification edge to the Tamron.

How they figure this mag issue I have no idea How close you can focus I suppose. The tamron lists at 10.6", the Nikon at 21.6"

Sony 24-70mm F4 Vario-Tessar T* FE OSS

12/31/2007 02:25:35 PM · #14

Yep, the maximum "native" magnification of a lens is based on it's design, how close it can focus.
You can certainly stack up more tubes than the focal length of the lens... for instance 100mm of tubes on a 50mm lens gives 2:1 magnification.

Bear_Music

Samsung Galaxy S24 Ultra

12/31/2007 02:45:37 PM · #15

There's another, expensive option that works extremely well; using a bellows on a focusing rail. You mount the camera to the back, the lens to the front, and use a gear drive to rack the lens back and forth over a considerable range of adjustment. I don't have one now, but I used to, and it was great. I used it with my 55mm Nikkor macro lens for extreme closeups. It's like a continuously variable extension tube.

This Novoflex unit is wonderful but very expensive.

Another handy thing to have is a focusing rail; it mounts between the camera and the tripod head and allows you to move the camera back and forth in minute (or larger, for that matter) increments. The best ones have side-to-side adjustments as well. VERY useful as an alternative to kludging around trying to get the tripod in *exactly* the right spot.

R.

levyj413

Apple iPhone 15 Pro Max

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Nikon

12/31/2007 02:53:31 PM · #16

Originally posted by Bear_Music:

Another handy thing to have is a focusing rail
R.

Yep! If I ever get serious, I'm definitely buying one. My example above was a matter of pointing my camera into the fibrous thing at various angles, looking through the viewfinder to see whether it looked interesting, shooting a bunch of stuff, and then looking to see what I caught. I would've gone nuts if there was something specific I needed to photograph.

cpanaioti

Canon EOS-40D

Canon EF 70-300mm f/4.5-5.6 DO IS USM

12/31/2007 02:58:09 PM · #17

Now that I have a true macro lens (Tamron 90mm) I may start using my macro rail.

I have all the other kit as well, but the lens produces much sharper images than either the use of the extension tubes or the closeup filters. The filters being the worst. It's fun playing with the tubes on a WA lens though. Just be wary of how close to the subject you are. 'o)

Sony DT 18-70mm f/3.5-5.6 Aspherical ED Zoom Lens for Sony Alpha

12/31/2007 03:00:33 PM · #18

Originally posted by levyj413:

Yep! If I ever get serious, I'm definitely buying one.

Oh, get serious! ;-)

Originally posted by levyj413:

I would've gone nuts if there was something specific I needed to photograph.

Yep, I can see that. Your "Lightness of Being" could have become unbearable!

paddles

Pentax K10D

Pentax FA 50mm f/1.4 AF

12/31/2007 08:51:24 PM · #19

Extension tubes are certainly the best of the budget ways to get into macro photography. If you do get more serious and buy a macro lens, you can always use the lens and the tubes together! I've used two tubes combined with my Tamron 90mm 1:1 lens more than once in the past.

kiwinick

Sony DSLR-A550

12/31/2007 09:06:06 PM · #20

Pro's will always use a macro lens which also doubles as a excellent portrait lens, Tubes, in my opinion are simply a 2nd rate way of doing things the canon 100 macro is a phenominal performer. As a pro you should strive for perfection