Extension Tubes with the 400mm f/5.6 L

[Mike-DT6]

I have read that quite a few people use an extension tube with the 400mm f/5.6 L when photographing small birds in order to reduce the minimum focus distance and get closer, to fill the frame more effectively.

I'm not sure if this a common use, but I would like to use an extension tube simply to bring my subject closer, so not really the same as achieving a smaller minimum focus distance.

My favourite bird photography spot is exactly 30 feet from my hiding place, which for small birds is still too far away. A goldfinch-sized bird cropped nicely only uses about 10% of the original frame, using the 400mm on my 20D.

Do any of you use extension tubes with your 400mm f/5.6 L (or any other telephoto) for bringing your subjects closer?

I am interested in finding out how each particular extension tube affects the maximum focus distance too, as well as depth of field, so that I know how far past my subject distance I can focus my lens. I have no idea how to work out maximum focus distance when using extension tubes, but would depth of field simply be calculated using the focal length of the lens with the length of the extension tube added (e.g. 400mm + 20mm = 420mm)?

The only information I can find regarding the use of extension tubes relates to minimum focus distance, when I'm mainly interested in maximum focus
distance.

Thanks

Mike

:-)

[gasrocks]

If your subject is within the normal range of focus for that lens (i.e. beyond the MFD such as 30 feet for the 400/5.6) then do not use an y ext. tubes. You will not gain anything and you will lose some light. If you want longer lenses then TCs are your answer. The 1.4x TC on the 400/5.6 becomes a 560/8 lens that still can focus at 30 feet. Bigger image.

[Mike-DT6]

Okay, thanks. I have a 1.4x TC on my wish list, but they're quite expensive!

Surely I would gain magnification with an extension tube, and also lose light with a TC wouldn't I?

Mike

[gasrocks]

Do not think of it as gaining magnification, just get to focus closer with tubes. 1.4x TC loses 1 f/stop. Get a used TC to save money. Tamron SP 1.4x TC is my favorite. I have 2 of them. The fit all lenses and can be stacked.

[Roy C]

Attached is a table of min/max focus distances with various tubes and the 400mm f5.6. Nothing scientific about the test, I just attached the tubes and measured the distances with a tape rule but it gives you an idea.

[Mike-DT6]

That's very helpful Roy, thanks. :-)

Mike

[Netgarden]

What camera do you use?
I ask because my 40D had focus issues with knock off teleconverters. Autofocus worked great, but I dealt with the majority of the photos OOF. My Point and shoot was sharper. These were clearly miss-focuses from the autofocus. I noticed the 40D would 'jump focus' sometimes you could see it in the viewfinder. This was with the Tamron 1.4x and the Promaster 2x. [they worked great on my 20D, so it must be the camera focus system.] I finally gave in and bought the canon 1.4x and it works well. However I got tired of the 40D focus quirks and bought the MKIII which autofocus works effectively with all teleconverters, even stacked. And for more ISO ability. So it may depend on which camera you have. I'd try them in store before buying a tele.

The 12mm tube is excellent between 4 ft. and 15 ft. No extra glass. Autofocus works great. Sorry I do not use the 400 5.6 but my friend does w/1.4x canon tele and has excellent results, although she has also the MKIII which she claims is the only way to go with a 5.6 lens+tele autofocus. The 400 5.6 +tele was not dependable for autofocus on her 30D. She uses higher ISO to solve the darker/slower image[in fact uses auto ISO when her teleconverter is on.]

Most teleconverters work excellent in manual focus. The focus issues are more tuned with camera than the tele. Even cheaper lenses do well with them in manual. Auto-focus is the issue for clarity.

[Mike-DT6]

Thanks for your reply :-)

I'm using a 20D. I would like a 1.4x TC, but I would only consider the Canon one. The extension tubes I would like anyway for macro, so I'll still get myself a set when I can.

Mike

:-)

[Roy C]

Thanks for your reply :-)

I'm using a 20D. I would like a 1.4x TC, but I would only consider the Canon one. The extension tubes I would like anyway for macro, so I'll still get myself a set when I can.

Mike

:-)
I have both Canon 1.4 tc and Kenko Pro 1.4 and IMO there is nothing to choose between them in terms of IQ. You need to remember that the Canon tc will only fit certain Canon lenses whereas the Kenko will fit almost any lens. I use a tc with my Canon 100mm f2.8 macro sometimes and the canon will not fit so I use the Kenko.

[Mike-DT6]

I originally thought that sticking to the Canon 1.4x TC would be the only sensible choice, as I thought it was designed for L series lenses, so would be better than the alternatives for image quality. Am I wrong in thinking this?

I did some reading after what you said and have found that some people claim the Kenko to be as good as the Canon with regard to image quality. Also I have seen the Tamron SP model mentioned and some claims were that it is better than the Canon model. Surely that can't be true can it?

Considering that the alternatives cost half as much and have equal performance, what reasons are there for buying the Canon model?

Mike

:-)

[hollis_f]

Okay, thanks. I have a 1.4x TC on my wish list, but they're quite expensive!

Don't forget that you won't be able to autofocus with a 1.4x on your 400 f5.6. Not unless you do the pin-taping trick. Even then AF will be paifully slow in all but great light.

[Mike-DT6]

Thanks, yes I realize that. :-) I use manual focus a lot with this lens anyway, so it wouldn't be too much of a problem.

Mike

:-)

[Roy C]

I originally thought that sticking to the Canon 1.4x TC would be the only sensible choice, as I thought it was designed for L series lenses, so would be better than the alternatives for image quality. Am I wrong in thinking this?

I did some reading after what you said and have found that some people claim the Kenko to be as good as the Canon with regard to image quality. Also I have seen the Tamron SP model mentioned and some claims were that it is better than the Canon model. Surely that can't be true can it?

Considering that the alternatives cost half as much and have equal performance, what reasons are there for buying the Canon model?

Mike

:-)
Mike, I have done several test with both converters and the 400mm f5.6 and IMO there is little to chose between them as far as IQ goes (with this lens anyway). I bought my Kenko Pro direct from Hong Kong at less than a third of the price of the Canon.
I have heard of someone who says that the Canon is better than the Kenko Pro when used with 500mm f4 but I guess if you ever come to buy a 500 f4 you could afford a Canon tc as well :) Also the Canon has better weather sealing I believe.

As already stated I can use the Kenko with my 100mm macro lens whereas the Canon will not fit.

BTW I understand that the Kenko Pro and the Tamron SP are the same converter with different badges although I cannot confirm this myself.

[Mike-DT6]

Thanks Roy

I'll definitely be considering the Kenko or the Tamron now, although I must admit that my camera bag would look better with all-Canon inside it - if only for OCD reasons! :lol:

Yes, I read about the similarities with the Tamron. I was doing some reading and apparently Tokina, Hoya and Kenko are the same company (THK Group). I also read that Hoya supplies lens glass to Nikon, Canon, Sigma, Tamron, Tokina, Olympus, Sony and more.

Mike

:-)

[Netgarden]

You might get more focus attempts with the Tamron or the Kenko. I switched to the canon II 1.4x for the 40D amd MKIII because of autofocus issues with the 40D + teleconverters. I think you'll be ok with the 30D, and possibly the knockoffs will do better because they don't report aperture, so autofocus should work.

[Roy C]

and possibly the knockoffs will do better because they don't report aperture, so autofocus should work.
If you mean by 'knockoffs' the likes of Kenko pro or the Tamron Pro then they do report the aperture just like the Canon, it is only the cheap Kenko's that have not got the reporting pins.

[Mike-DT6]

It's strange that the non-Canon models should have the auto-focus functionality on the lower spec bodies and not the Canon model.

I wonder what Canon's reason was for effectively disabling it. Could it be that the loss of light makes the auto-focus too much of a hit-and-miss affair for Canon's liking?

Mike

[Roy C]

I wonder what Canon's reason was for effectively disabling it. Could it be that the loss of light makes the auto-focus too much of a hit-and-miss affair for Canon's liking?

Mike
As far as xxxD and xxD cameras are concerned I think you have hit the nail on the head Mike, they are designed to AF up to f5.6 so if canon allow AF over that then the AF may not be very effective. Having said that it is so easy to fool the camera into attempting to AF over f5.6 that is does not really matter that Canon has disabled it.
What we really want from Canon is a xxD camera with the same AF capabilities as the xD range (e,g, centre focus point AF up to f8 ) Cant see this happening though as they would lose a big chunk of their xD sales.

[gymell]

Yes, I've used extension tubes with the 400 to get quite close. The quick AF, and wider field of view than the 500, makes that a good lens for capturing hummingbirds in flight. The extension tube dramatically reduces DOF. For example:

http://www.pbase.com/gymell/image/84715946/original.jpg

And:
http://www.pbase.com/gymell/image/84769506/original.jpg

[BradM]

If your subject is within the normal range of focus for that lens (i.e. beyond the MFD such as 30 feet for the 400/5.6) then do not use an y ext. tubes. You will not gain anything and you will lose some light. If you want longer lenses then TCs are your answer. The 1.4x TC on the 400/5.6 becomes a 560/8 lens that still can focus at 30 feet. Bigger image.


I have to disagree, extension tubes will increase the image size on the sensor when using the same lens at the same distance vs. the lens without the tubes. The main issue that results is a loss of infinity focus, light loss does occur but is very minimal, is some cases with either the 100-400 or 400 is what something like a 1/3rd of a stop, compared to a full stop for the 1.4x. And there is very little loss of image quality compared to using a extender.

So if the subject can fall into the range of focus that the lens has with whatever length of tubes is one using then I find the results can be better than using an extender.

Got beat to it, but here is a shot of a hummer using 36mm of ext. tubes behind the 100-400mm. Somehwere I have shots as well of using them behind a 300-800mm of hummers, as well as some "test" shots of a tennis ball showing the level of magnification using a different series of extension tubes.

http://i7.photobucket.com/albums/y259/Bradklr/hummerflight.jpg

[Mike-DT6]

Thanks for the latest replies Roy, Liz and Brad. :-)

Some great photographs there. My subject distance of 30 feet is too far to use extension tubes to that effect, but I can think of other situations where I could use them on my 400mm, in addition to their use for macro.

Equally I can see that I could make good use of a 1.4x TC, so I suppose I'll end up getting both at some point! :lol:

Mike

[Bill Boehme]

Don't forget that you won't be able to autofocus with a 1.4x on your 400 f5.6. Not unless you do the pin-taping trick. Even then AF will be paifully slow in all but great light.

Can you tell me the pin taping trick? I don't know the secret handshake.

[hollis_f]

Can you tell me the pin taping trick? I don't know the secret handshake.
There's a description plus photo here (http://www.fredmiranda.com/TipsPage/).

It stops the TC telling the camera that it's attached, so it will try and AF even when it's not supposed to. However, you still have the problem of a small aperture (f8) which greatly reduces the amount of light that gets to the AF sensors. This can really screw up the AF in all but very good light.

[Bill Boehme]

There's a description plus photo here (http://www.fredmiranda.com/TipsPage/).

It stops the TC telling the camera that it's attached, so it will try and AF even when it's not supposed to. However, you still have the problem of a small aperture (f8) which greatly reduces the amount of light that gets to the AF sensors. This can really screw up the AF in all but very good light.

Thanks for the response, Hollis. I can appreciate the low light focusing issue since my XTi is not a stellar performer with respect to good focusing even in moderate lighting without a TC attached.

Just a rhetorical question: I wonder why Canon uses the term extender when almost everyone else uses teleconverter. It was confusing me for a while because I thought that they were referring to extension tubes.

[gmax]

Hi Mike,

my regular kit is: 20D + 400mm f/5.6 + Canon 1.4x TC (which I prefer to other brands) ... I'm overall quite satisfied with ;) , were it not for my faithful camera dying out :confused:

If you wish, check my pictures (98% are taken with a TC on) on Birdforum.net (username: gmax), or on my website (www.bataki.it (http://www.bataki.it)), or ask Roy C on here :D :lol:

Cheers,

Max

[Mike-DT6]

Thanks Max, I'll have a look. :-)

Mike

[Rich S]

Kenko Pro 300 is great . I used it on this shot......... http://i212.photobucket.com/albums/cc150/blackies_owner/_MG_4706_edited-1.jpg

[Mike-DT6]

Excellent capture! :-)

Mike

[canonloader]

With the 400/5.6, maximum focus distance with the 12mm is about 35 feet, and gets less, the longer the tube. The 20mm is a great all around tube, will keep AF, uses no light, doesn't change the f/stop and will magnify the frame a good deal. If you are not shooting over 30 feet, it's a win/win situation all around.

[Bill Boehme]

With the 400/5.6, maximum focus distance with the 12mm is about 35 feet, and gets less, the longer the tube. The 20mm is a great all around tube, will keep AF, uses no light, doesn't change the f/stop and will magnify the frame a good deal. If you are not shooting over 30 feet, it's a win/win situation all around.

Mitch, you are a storehouse of very useful information. Thanks for the great tip. Now, I just need to get the 400/5.6 that I have been wanting for months.

[Mike-DT6]

Thanks Mitch :-)

I have just got a set of extension tubes, so I'll be able to give it a try now. :-)

Mike

[canonloader]

Thanks Bill. I sold mine awhile back, thinking I needed the Bigma and extra 100mm. Now I am saving for another 400/5.6 and the Bigma has gone to a place with more light. :)

[Methodical]

Thanks Mitch :-)

I have just got a set of extension tubes, so I'll be able to give it a try now. :-)

Mike


Mike, you have any updates on this. I'm considering the extension tubes too also.

Thanks

[canonloader]

My new 400/5.6 was just delivered. I will be trying out the tubes again on it soon. :)

[CyberDyneSystems]

Thanks for the latest replies Roy, Liz and Brad. :-)

Some great photographs there. My subject distance of 30 feet is too far to use extension tubes to that effect, but I can think of other situations where I could use them on my 400mm, in addition to their use for macro.
...

I just want to make sure we are clear on what you hope to achieve,..
All an extension tube does is allow you to force an otherwise uncooperative lens to focus on subjects that are actually closer to you than the lens would otherwise be able to focus.
That is the only way an extension tube will allow you as a photographer to get "more magnification" using a tube. Adding a tube on it's own will do nothing but make the image darker,. to gain any benefit, you need to be able to get closer...

Forgive me if you grasp this , but some of your comments led me to believe there may be some confusion.

[Scottes]

Adding a tube on it's own will do nothing but make the image darker,. to gain any benefit, you need to be able to get closer...
Sorry, that's not true.

Here's a test I did - 5 years ago - with tubes on a 100-400 L.
http://photography-on-the.net/forum/showthread.php?t=28037

In a nutshell, without moving the camera:
A 12mm tube shows a 10% magnification over the tubeless version.
A 20mm tube shows a 15% magnification over the tubeless version.
A 36mm tube shows a 27% magnification over the tubeless version.


Here's a little more info, and examples, keying on the tube's effect on minimum focus:
http://photography-on-the.net/forum/showpost.php?p=170085&postcount=7

[canonloader]

I don't think that I'll ever leave the house without my tubes from now on.
I always have mine with me. I bought tubes right after getting my first DSLR, an old used D30. The Kenko tube set is the only thing I still have from those days, and I use them almost every day for birds. :)

[Roy C]

Sorry, that's not true.

Here's a test I did - 5 years ago - with tubes on a 100-400 L.
http://photography-on-the.net/forum/showthread.php?t=28037

In a nutshell, without moving the camera:
A 12mm tube shows a 10% magnification over the tubeless version.
A 20mm tube shows a 15% magnification over the tubeless version.
A 36mm tube shows a 27% magnification over the tubeless version.


Here's a little more info, and examples, keying on the tube's effect on minimum focus:
http://photography-on-the.net/forum/showpost.php?p=170085&postcount=7
You are quite right 'Scottes' extension tubes will give you some increased magnification also you do not lose a lot of light.

[Tom Reichner]

I'm not sure if this a common use, but I would like to use an extension tube simply to bring my subject closer, so not really the same as achieving a smaller minimum focus distance.
The use of an extension tube will not bring the subject any closer, or help it to fill the frame more.
All it will do is help you be able to focus when you're closer to the subject than the lens' minimum focus distance. It does not act like a teleconverter ("extender").
If you can re-create your setup so that you're about 10-15 feet from the birds instead of 30 feet, you will notice a dramatic improvement in the quality of your bird photos.

[Rich S]

Good explanation....Rich

[BradM]

The use of an extension tube will not bring the subject any closer, or help it to fill the frame more.
All it will do is help you be able to focus when you're closer to the subject than the lens' minimum focus distance. It does not act like a teleconverter ("extender").
If you can re-create your setup so that you're about 10-15 feet from the birds instead of 30 feet, you will notice a dramatic improvement in the quality of your bird photos.


This keeps going back forth, that it doesn't increase image size on the sensor or that it does. It is boring and there is only one correct answer.

It not only reduces a minimum focus distance but it will also slightly increase the subject size on the sensor.

There is no physical or optical rule that states you can use extension tubes with a 100mm lens to go larger than 1:1 but you cannot do so with a 500mm lens shooting birds or wildlife.

The primary and significant difference is that the effect when using a longer lens is much less than it is with the 100mm which is less than it with a shorter focal length (that is if the focus point does not move beyond the sensor plane) but the fact remains it does increase the subject size projected on to the sensor.

Here is two images both shot from 15' with the 1D3 & 500mm f/4, one with the lens straight up, the other with all exactly the same but with a 20mm extension tube I could have gone to 68mm and had a much more significant difference but I use this tube regularly to reduce my mfd to about 12' and still keep infinty at about 70', more than covers my usual ranges.

These were handheld and the focus point was roughly the center of the ruler so there is some slight difference in centering but the values are easily measurable. No post only resizing, these are as captured.

One of the rules, the straight 500mm measures (roughly) 10.3125 inches, 10 & 5/16th's

The other with the 20mm extension tube measures 9.8125, 9 & 13/16th's

An increase in magnification of 5%. Count it out and do the math, it works every time with almost any lens (that caveat was mentioned earlier) and any extension tube.

This is simple optics, you pull the light being gathered from the lens and projected onto the sensor away from the sensor and the area of the light increases, some of which will now fall outside the bounds of the sensor. The light that does fall onto the sensor now has a larger projected image.

Similar to using a slide or overhead projector, push the projector closer to the screen and the image projected gets smaller, puull it away and it get larger.

http://i7.photobucket.com/albums/y259/Bradklr/9_13_16th.jpg


http://i7.photobucket.com/albums/y259/Bradklr/9_5_16.jpg

[Mike-DT6]

Thanks for the latest replies everyone. I hadn't been receiving e-mail notifications up until the last post, so I missed a lot of the newer posts.

I must say that I'm a little confused. I have forgotten most of the details, but as a child I used to use extension tubes with a lens on my camera to magnify the subject and it used to work well. This was at a fixed point (next to the track at the bike racing) and with the tubes it used to magnify what I was seeing. I didn't need to get closer to take advantage of the shorter minimum focus distance, it just magnified the view from where I was standing.

This experience was the basis for my question regarding my 400mm and wanting to bring my subjects closer from a fixed position. I appreciate the theory regarding minimum focus distance and how that is applied, but my question regarded a fixed distance from the subject, which happens to be the distance from my usual vantage point to the bird bath in my back garden!

I wish I could remember what lens I used to use and what tubes I was using, but it was so long ago I can't remember. All I can remember is that it wasn't a particularly short lens and I remember the tubes being quite long - and that the effect was quite pronounced. A lot of the quoted theory on this is telling me that I couldn't have done this, but I did!

I still haven't tried my extension tubes on my 400mm, so have nothing to report yet!

Mike

:-)

[canonloader]

Sorry Tom, can't agree. Kenko tubes makes it "appear" to bring it closer, by magnifying what hits the sensor. By moving the rear element of the lens further from the sensor, it moves the actual focus point further away, and in doing that, the old focus point is made bigger.

[Bill Boehme]

Sorry Tom, can't agree. Kenko tubes makes it "appear" to bring it closer, by magnifying what hits the sensor. By moving the rear element of the lens further from the sensor, it moves the actual focus point further away, and in doing that, the old focus point is made bigger.

You have angered the Series 800 Model 101 Admin Droid.

"I see your point, sir. I suggest a new strategy, R2: let the Wookie win" ... C3PO.

[canonloader]

Ah well, can't win them all. I even went though my old archive shots of when I tested my first 400/5.6 with the tubes. From a tripod, same camera, same distance, the object got bigger in the frame, however else you want to describe it. :)

Not very dramatic, but here is another test, shot just now;

12mm...
http://www.picturelacrosse.com/test/1dmk2n/12mm-1d2n7517-052609.jpg

20mm...
http://www.picturelacrosse.com/test/1dmk2n/20mm-1d2n7518-052609.jpg

36mm...
http://www.picturelacrosse.com/test/1dmk2n/36mm-1d2n7519-052609.jpg