April 21, 2014, 02:37:14 AM

Author Topic: 70-200mm f/2.8L IS II with a 25mm extension tube  (Read 7344 times)

contrastny

  • Guest
70-200mm f/2.8L IS II with a 25mm extension tube
« on: June 03, 2011, 01:44:02 PM »
I am going to get the 70-200mm II within the next few weeks. I'm also planning on using it with an extension tube for butterfly shots. I have the 180mm f/3.5L, but since butterflies are fast subjects I would like to use the AF on the 70-200mm. When I plan to captue the whole butterfly it's not a try macro photo of a 1:1 ratio anyway, with the larger butterflies it's probably more like a .3 or .4 to 1.

What magnification will a 25mm tube change the 70-200mm to? I know a fixed 50mm will be .5, but I'm not sure with a zoom...

Has anyone used the 70-200 with an extension tube?

Thanks,

canon rumors FORUM

70-200mm f/2.8L IS II with a 25mm extension tube
« on: June 03, 2011, 01:44:02 PM »

neuroanatomist

  • CR GEEK
  • *******
  • Posts: 12793
    • View Profile
Re: 70-200mm f/2.8L IS II with a 25mm extension tube
« Reply #1 on: June 03, 2011, 03:03:14 PM »
What magnification will a 25mm tube change the 70-200mm to?

Magnification with a 25mm extension tube mounted behind a 70-200mm f/2.8L IS II will range from 0.36x at 70mm to 0.14x at 200mm (extension tubes change the maximum magnification based on the ratio of the tube length to the focal length, so the longer the lens, the less effective the extension tube).  Obviously, you lose infinity focus with the extension tube, and you also lose light (meaning higher ISO or longer exposures).

For higher magnification with a telezoom, a close-up lens is usually a better choice.  With a Canon 77mm 500D Close-Up Lens screwed onto the front of a 70-200mm f/2.8L IS II, magnification will range from 0.14x at 70mm to 0.60x at 200mm.  The downside to the close up lens is a fixed working distance - in the case of the 500D, that means you'd need to be about 15-20" from the butterfly - no more and no less.

I have not used an extension tube with my 70-200mm f/2.8L IS II, however, I have used a 500D close-up lens and gotten nice results.  I did some informal testing in the available magnification range of the 70-200 II + 500D, and when shooting the same subjects the IQ came impressively close to my 100mm f/2.8L Macro IS. 
« Last Edit: June 03, 2011, 03:05:17 PM by neuroanatomist »
EOS 1D X, EOS M, and lots of lenses
______________________________
Flickr | TDP Profile/Gear List

contrastny

  • Guest
Re: 70-200mm f/2.8L IS II with a 25mm extension tube
« Reply #2 on: June 03, 2011, 06:45:31 PM »
What magnification will a 25mm tube change the 70-200mm to?

Magnification with a 25mm extension tube mounted behind a 70-200mm f/2.8L IS II will range from 0.36x at 70mm to 0.14x at 200mm (extension tubes change the maximum magnification based on the ratio of the tube length to the focal length, so the longer the lens, the less effective the extension tube).  Obviously, you lose infinity focus with the extension tube, and you also lose light (meaning higher ISO or longer exposures).

For higher magnification with a telezoom, a close-up lens is usually a better choice.  With a Canon 77mm 500D Close-Up Lens screwed onto the front of a 70-200mm f/2.8L IS II, magnification will range from 0.14x at 70mm to 0.60x at 200mm.  The downside to the close up lens is a fixed working distance - in the case of the 500D, that means you'd need to be about 15-20" from the butterfly - no more and no less.

I have not used an extension tube with my 70-200mm f/2.8L IS II, however, I have used a 500D close-up lens and gotten nice results.  I did some informal testing in the available magnification range of the 70-200 II + 500D, and when shooting the same subjects the IQ came impressively close to my 100mm f/2.8L Macro IS.

Thanks for the info!
It seems like the 500D is a much better route, however, I might just use my 300mm f/4 IS for butterflies since it has a magnification of .24 at 300mm, and the AF is still much faster than the 180mm f/3.5 L. For large butterflies .24  might be all that I'll need when I'm capturing the whole butterfly. The 15-20" working distance of the 500D might be too close for butterflies.

I assume the maximum magnification of .21 for the 70-200mm is at 70mm (without tubes or close-up filters). What is the max magnification at 200mm (without tubes & filters)?


mindPlant

  • Guest
Re: 70-200mm f/2.8L IS II with a 25mm extension tube
« Reply #3 on: June 03, 2011, 07:18:41 PM »
the-digital-picture.com has the nubers:
http://www.the-digital-picture.com/Reviews/Canon-EF-70-200mm-f-2.8-L-IS-II-USM-Lens-Review.aspx

I would not recomend the 500D Filter. You have a limited focus area and that would nullifie your fast focus idear.
About the tubes: the AF will be crippled by it a tube.

Ever thought about the new 100mm L IS? The focus is pretty fast on it. The 300mm F4 isn´t so great for "macro" use I tyed it on some butterflys last summer and the fixed 300mmm was often too long.


gene_can_sing

  • Guest
Re: 70-200mm f/2.8L IS II with a 25mm extension tube
« Reply #4 on: June 04, 2011, 02:32:24 AM »
Extension tubes are very, very limiting. I would just shell out the money and get a real macro. Trust me, it will save you a LOT of frustration.

When you use an extension tube, you Minimum and Maximum focus range is extremely, extremely limited. For example, I tried to used an extension on the Canon 50mm f1.4. I can't remember the exact distance, but basically, the camera could only be about 7 to 9 inches from the subject to be in focus. If you veer from the 2 inch range of focus, it is absolutely impossible to get correct focus.

To put that into perspective, on the 50mm without the Extension tube, the camera can be anywhere from 15 inch to as far back as you want to go to achieve focus (Infinity). Now imagine, that you only move 2 inch forward and backward. If you move more than 2 inches, it's impossible to get anything approaching correct focus.

So yes, just buy a real macro. You will be much happier and less frustrated.

Flake

  • Guest
Re: 70-200mm f/2.8L IS II with a 25mm extension tube
« Reply #5 on: June 04, 2011, 03:04:08 AM »
You say you have a 180mm Macro (Either Canon or Sigma?)  Both lenses have focus limiting switches which will greatly speed up focus, on the Canon lens the switch stops the focus going closer than 1.5 Metres, on the Sigma .82 Metres to infinity.

A 180mm Macro lens is difficult to get good shots from and although I have one I do also have the 100mm L which is much easier to use, again it has a focus limit switch to speed things up which is .5 Metre to infinity.

The closer you get with a macro lens the further the focus has to travel, which is why they appear slow when they hunt over the entire focus, cutting the close end out will make your lens much much quicker to attain focus, and you can help it with some manual input.

dr croubie

  • 1D X
  • *******
  • Posts: 1397
  • Too many photos, too little time.
    • View Profile
Re: 70-200mm f/2.8L IS II with a 25mm extension tube
« Reply #6 on: June 04, 2011, 03:57:00 AM »
a) how big are the butterflies you want to get?
b) do you want them to fill the screen, or have a nice background?
c) which camera?

I took my 7D + 70-300 non-L to a butterfly house recently, and my 12/20/36mm kenko tubes.
http://www.canonrumors.com/forum/index.php/topic,307.0.html for a sample (there's better ones i haven't uploaded yet). i started out with longer tubes, ended up with just the 12mm, and gave up on autofocus altogether by the end of it. (ok, so the 70-200L will beat it in autofocus speed, but like everyone's said, with tubes they just *hunt* all the time). one finger on zoom ring, one of focus ring, one on cpl (damn non-L rotating element) and jumping around everywhere. i accidentally stepped on a lot of feet that day.


so, looking at the specs, the MM of the 70-200L 2.8 ii is 0.21x. on a 7d sensor, that means your framing width is 22.3x14.9mm / 0.21x = 10.6cm x 7.09cm, at max. mag.
on a 5D, you get 17.1cm x 11.4cm.

so either way, yeah, you'd need a big butterfly to fully fill those images. cf the image i linked above, that's uncropped, and the butterfly is about 4-5cm across, the whole image is maybe 7x5cm. so you can get the same scaling on a 7D with your lens. with a 5d you'll get a bit more space on the edges.


adding the +12mm ring gets you .28x or +25mm gives you .36x.
firstly, my advice is get the kenko tubes. 3 rings gives you +12/20/32/36/48/56/68 combinations. and all for the price of less than one canon ring (aside, are the canon rings sealed? that'd be the only reason i'd pay a premium for a bit of air-spacing)

secondly, my advice is to skip the rings, if you want the 70-200 2.8 for other things, get it and crop. if you only want to take insects, get the 100LIS macro. (with the money saved, get a teleconverter too?)

thirdly, it is possible to get used to MF using rings. your zoom ring also acts as a sort of focus ring once you put the tubes on, every focal length will only have a small focussing range, it can be easier to zoom in/out than move forward/back.

lastly (if you don't already do this). High Speed Continuous is your friend. crappy shots can be deleted later, memory is cheap, and you can always crop something good out of a wider shot. if you spend too long framing and getting closer to fill the frame, it'll just fly away eventually and you get nothing...
Too much gear, too little space.
Gear Photos

canon rumors FORUM

Re: 70-200mm f/2.8L IS II with a 25mm extension tube
« Reply #6 on: June 04, 2011, 03:57:00 AM »