Close-up lens vs extension tube for EF70-300 F4.5-5.6 DO IS USM

[hauskurz]

I hate to change lenses while hiking because of dust, etc. and time to do it (The bird will have flown if I want to use max telephoto).  In addition to birds and critters, I also like to photograph flowers.  So there are two ways to allow me to get close-ups with this lens.  I have read that with a telephoto lens a close-up lens screwed on the lens is better than an extension tube.  Is this true?  If so, which ones would be suitable to use with this lens?

If the extension tube option is better, what would be the effect of leaving it on the camera with regard to ability to use max telephoto?  (Remember, on the trail, changing lenses is a pain).

[trulandphoto]

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@hauskurz wrote:

I hate to change lenses while hiking because of dust, etc. and time to do it (The bird will have flown if I want to use max telephoto).  In addition to birds and critters, I also like to photograph flowers.  So there are two ways to allow me to get close-ups with this lens.  I have read that with a telephoto lens a close-up lens screwed on the lens is better than an extension tube.  Is this true?  If so, which ones would be suitable to use with this lens?

If the extension tube option is better, what would be the effect of leaving it on the camera with regard to ability to use max telephoto?  (Remember, on the trail, changing lenses is a pain).

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Both close up lenses and extension tubes have their advantages and drawbacks.

Specifically with a zoom lens like yours, the advantage of the 500D closeup lens is that it doesn't lose any light and you don't have to reposition or refocus as much if you zoom in or out after focusing as you would with an extension tube. And it's easier to screw the lens on and off than removing an extension tube.

Advantages of the extension tube are that it doesn't add any glass which will degrade the image somewhat. And with multiple size tubes there's more flexibility.

I use both, preferring the closeup lens with zooms and extension tubes with prime lenses.

[Bill-Emmett]

With both of these setups there are difinate reasons not to use either.  First extension tube add mm of lenth to your lens, which allow the minimal working distance of the to be reduced.  You may find yourself within the comfort zone of the bird you are going to photograph, and before you can set up, the bird gets scared and flys off.  Second, you have bought a expensive piece of glass to photograph the bird, in the form of Canon "L" quality glass.  Why do you want to place a cheap lens infront of the "L" glass.  Why not just get a 1.6, or 2X extender to place between the body, and lens?  These extender are available in 1.6, 2X, and even 3X, and can be stacked.  (although I don't recommed it, and don't recommend a 3X extender either.)  Be sure when you shoot using a extender the light is bright, since you will loose some f stops depending on the quality of the extender.  Check with Canon if the Canon extender is compatable with your 70-300mm lens.  It may not be, since the rear element of the extender protrudes into the cameras sensor chamber.  Other extenders will work since they do not have the protruding lens.  Using a extender will give you good image quality, but not as good as without the extender.  There is always a trade off.  

[hauskurz]

I have read that telephoto lenses work better with a close-up lens just as you imply. However, i can find no information as to what are the advantages of a 1 or 2 element lens and how much these will reduce the minimum focusing distance of my lens.

[amfoto1]

For several reasons, I prefer to use extension tubes instead of close-up lenses. One is the inevitable image degradation that adding any form of glass in front of a lens will cause. That loss of IQ might be slight under ideal conditions and with top quality close-up lenses... or it might be pretty significant in more difficult lighting, etc. Another reason is the price... a large, good quality close-up lens costs nearly as much as a set of high quality extension tubes, which offer more flexibility because they can be used on any lens and in a variety of ways. The close-up lens is largely dedicated to use on a particular lens (or other lenses that use the same size and match the same magnification. There are no optics in extension tubes, so they effect image quality less.

If you choose to use a close-up lens, beware of cheap. ones... the $20-25 sets of four are terrible and will ruin your images. Spend more for quality, two-element close-up

The Canon close-up lenses 250D and 500D are high quality, two-element diopters.

The 250D is designed for shorter focal length telephotos, is only available in smaller diameter sizes and is the stronger of the two. It reduces working distance to around 250mm.

The 500D is designed for longer focal length telephotos and reduces working distance to around 500mm.

I've got a 77mm 500D that I occasionally use on 70-200/2.8. But, frankly, it costs some image quality... there's some loss of resolution and overall increase in veiling flare that tends to reduce contrast and color saturation. It does not appear to be multi-coated, so plan to use a lens hood to keep oblique light off of the lens.

Now, I believe your lens uses a 67mm filter... and I don't see the 500D close-up lens offered in that size. You'd have to use a 72mm size and step ring... which would preclude using a lens hood. The 72mm 500D alone sells for $125 US.

Personally I'd go with extension tubes, instead. For 25 or 30 years shooting with various systems I always have a set of ext. tubes with me... they are so handy to have for a quick macro shot or just to improve the closest focusing of a longer tele. A set such as the Kenko costs right at $200 (incl. 12mm, 20mm and 36mm tubes). It's much more flexible, I've used them on lenses from 20mm to 500mm, zooms and primes, and even on macro lenses when I wanted higher than 1:1 magnification.

There is some light fall off in extension tubes, but if relying upon the camera's built-in metering system, that will compensate. Some lenses tend to vignette a bit when an extension tube is added, but that's usually strongest with shorter focal lengths and the lens' largest apertures, can be controlled a bit by stopping down. Also, shorter focal length might show some softening in the corners, with extension tubes.

Adding tubes slows autofocus, a little more with each additional connection. Also, using a lot of extension, stacking a lot of tubes, such as might be needed with a longer focal length lens, you have to be a bit cautious about the weight of camera and lens, though the Canon tubes (only sold singly in 12mm and 25mm lengths) and the Kenko (set of three, or individually sold) are pretty sturdy with strong latching mechanisms. Some of the less expensive tubes (Zeikos, which are rebranded under many names, and Opteka) are more plasticky and don't appear to have as strong latching mechanisms. For a relatively large lens like the 70-300L, I think I'd recommend sticking with the better quality tubes from Kenko or Canon.

Someone suggested using a teleconverter instead of extension tubes or close-up lens...  Canon calls their teleconverters "Extenders", not to be confused with macro extension tubes. Yes, a high quality teleconverter does offer greater magnification, because the lens' minimum focus distance remains the same when the TC is added. However, a quality TC is more expensive, and with an f4.5-5.6 zoom you will lose autofocus even with a 1.4X. A TC reduces light... One stop with a 1.4X and two stops for a 2X TC. Adding a 1.4X to an f4.5-5.6 lens makes it an effective f6.3-8.0. Adding a 2X would make that lens an effective f9.0-11. Most Canon cameras will stop AFing beyond f5.6. Some can do f8 at center AF point only. There are work-arounds that trick the camera into trying to focus... but AF will be noticeably slowed, at best, is likely to hunt and fail depending upon lighting conditions. Also note that all the Canon 1.4X and 2X teleconverters have a protruding front element that physically prevent them from being used on quite a few lenses. Canon recommends them only on primes 135mm and longer, and only the 70-200mm zooms.

Oh, and stop worrying about changing lenses. That's really silly. I shoot a lot in extremely dusty conditions - rodeos, gymkhanas, off-road motorsports & cycling, etc. - and have shot in the Mojave, Sonoran and Arabian deserts. (A dusty example: http://www.flickr.com/photos/amfoto1/8982944000/) I change lenses all the time with normal precautions, rarely carry less than three lenses see very little problem changing them, with dust or anything else.

Today's cameras with self-cleaning sensors are pretty effective dealing with dust. One of my 7Ds has been in use for four years, taken close to 100,000 images, and has never required cleaning. The other (same age and usage) has been cleaned once. I think I've cleaned my 5DII once, too, and have had that longer than the 7Ds. Prior to self-cleaning sensors, I did have to clean 30D and 10D once a year at least, sometimes more often. I never owned a 5D classic, in part out of "fear of dust", but now that I know how easy cleaning is... and how seldom it's really needed...  I think I was just being silly.

So just use some common sense and change your lenses. Besides, dust isn't anything new... we had problems with it when shooting film and developing prints in darkrooms, too... in fact it is generally less damaging and much more easily dealt with now, shooting digital.