AF with Canon 400mm f5.6 and extension tube

[gatafrancesca]

Hi again everybody!
Having finally decided wich lens, tripod and head I will buy, now I want more!!
I think if I can afford it I will buy a Tamron 1.4X TC, but I also thought about buying a 12mm extension tube to help me with small birds photography. I have read some threads about this and I see that there are some folks using the same lens with extension tubes, but I still have some doubts.
First of all, as long as I have correctly understood the info published here, I will lose some light if I attach an extension tube to the lens, so my question is: if I lose an f stop or so, will I still be able to autofocus? I had a look at both the Kenko and Canon ET. The Canon Extension Tube EF 12 II, is said to be better used with manual focus, however, I think I have seen some pictures here in BF that were taken with this setup and AF. Then there is the Kenko 12mm UniplusTube DG, wich is much cheaper, but it comes with this info: "Retains AF function when effective aperture stays at f/5.6 or brighter(f/8 or brighter on EOS 3, 1V & 1D cameras)". So I am a little bit confused here...If I lose an f stop by putting on the extension tube, I will not be shooting at f5.6, so I should lose autofocus, is that so? Is the Canon version any better?
For reference, I had a look at this site:

http://www.birdimages.co.uk/

Most of the great photos I found there have been taken with the 12mm Canon ET and they seem to be AF mode.
So please, I know that there are quite a bunch of people out there using the Canon 400mm f5.6 , can any of you please help me out?
Thank you

Francesca Albini
San Cristóbal de Las Casas
Chiapas, Mexico
gatafrancesca@yahoo.com

[tirc83]

The 1.4x converter would be handy as it would give you greater range, albeit with a stop less exposure. The 12mm tube would have the opposite effect, letting you focus closer than the minimum focusing distance of the lens.

There are 2 kinds of extension tube, one that allows auto-focus to continue working and the cheaper variety which needs manual focusing and doesn't stop down the lens.

[Roy C]

I have used extension tubes with this lens to reduce the minimum focusing distance. With a 25mm tube the min focusing distance is around 2.5 mtrs (3.5 mtrs without tubes) the maximum focusing distance with a 25mm tube is around 12 mtrs. There is no problems with auofocus.

[jiminlondon99]

Having seen the great results of others in this forum I bought a set of Jessops extension tubes to use with my 400mm prime and I am delighted with the results. I find them ideal for close focus for slow moving butterflys. A rough guide to the depth of field using the various combination of the 3 tubes is;
65mm = 3-4 paces
52mm = 3-5 paces
31mm = 3-7
21mm = 3-9
12mm not measured


I also have the 60mm macro lens but find the 400+tubes is far easier on my knees and neck! The picture below was taken with my 30d+400 prime & 3 tubes.
See my gallery for a recent shot using all 3 tubes and full AF.

Jim

[IanF]

Same here - extension tubes are a real boon for this lens. I wouldn't bother with the Canon ones though as they're way over priced. Extension tubes are simply hollow metal tubes - no glass at all which makes you wonder why the Canon ones are so expensive.

Life is a lot easier though if you use auto-extension tubes - as these retain autofocus with no problem at all. There is light loss using them but only an f-stop or two depending on the length of the tubes.

I've been using them with the 400mm f5,6 and 100-400mm zoom - just a cheap set of auto extension tubes.

I'm not sure I'd bother with the 12mm though. I always reach for the 30mm tube as it gives a decent reduction in focus distance without too much light loss. You can use them for very close birds, but really it's butterflies and other insects I find them most useful for. It's seldom I get the opportunity of photographing birds less than the minimum focus distance of the lens alone.

As regards teleconverters then I use the Canon 1.4x which with the 400mm f5,6 there is very little loss is optical quality. Be aware though that with the 350D, 20D or 30D you lose autofocus unless you tape the three pins and even then it can be very slow to operate.

[gatafrancesca]

Thanks everyone for your comments. Maybe a reason to go for a Canon extension tube and not for a Kenko is that the last one appears to be "Not compatible with the Canon Digital-only EF-S lenses, 18-55 f/3.5-5.6, 17-85 f/4-5.6, 60 f/2.8 macro" according to the info form the manufacturer. So I wouldn't be able to use it with the lens that came with my 350d, the EF-S 18-55mm. No problems with the 400mm EF lens anyway.
Unfortulately no cheap Jessops here :-(

Francesca Albini
San cristóbal de Las Casas
Chiapas, Mexico
gatafrancesca@yahoo.com

[gmax]

I have used extension tubes with this lens to reduce the minimum focusing distance. With a 25mm tube the min focusing distance is around 2.5 mtrs (3.5 mtrs without tubes) the maximum focusing distance with a 25mm tube is around 12 mtrs. There is no problems with auofocus.

Correct, but much depends on what types of birds you are going to shoot at ... if birds aren't tame in your area (as aren't in mine), there will be very few chances where the lens's MFD is an obstacle (BTW even though the 400mm f/5.6's MFD is 3.5m, by manual focussing it you can bypass this limit: I'll post asap a couple of shots in MF taken at ca. 2.5-3m without tube, but with a 1.4x TC).
I mainly go shooting in wetlands, ponds, etc, where a long range lens is mostly needed; at times, I go walking in woods or on the mountains, yet birds don't usually come that close. Therefore, I personally would not bother buying extension tubes just for birding, unless you want to use them also with other subjects (butterflies, dragonflies etc); sometimes a step back is just what you need to get in-focus subjects.
As for TCs, my only experience is with the Canon Extender 1.4x and I agree with Ian that there's just a little loss in image quality, although AF hunts at times (you just have to get used to it)
Cheers,
Max

[Roy C]

Correct, but much depends on what types of birds you are going to shoot at ... if birds aren't tame in your area (as aren't in mine), there will be very few chances where the lens's MFD is an obstacle (BTW even though the 400mm f/5.6's MFD is 3.5m, by manual focussing it you can bypass this limit: I'll post asap a couple of shots in MF taken at ca. 2.5-3m without tube, but with a 1.4x TC).
I mainly go shooting in wetlands, ponds, etc, where a long range lens is mostly needed; at times, I go walking in woods or on the mountains, yet birds don't usually come that close. Therefore, I personally would not bother buying extension tubes just for birding, unless you want to use them also with other subjects (butterflies, dragonflies etc); sometimes a step back is just what you need to get in-focus subjects.
As for TCs, my only experience is with the Canon Extender 1.4x and I agree with Ian that there's just a little loss in image quality, although AF hunts at times (you just have to get used to it)
Cheers,
Max

I never said I used tubes for bird shots, but was just pointing out the focusing range that you will get with a 25mm tube.
I have used tubes for butterflies and dragonfles as 3.5 mtrs can be a bit restrictive.

[gmax]

I never said I used tubes for bird shots, but was just pointing out the focusing range that you will get with a 25mm tube.
I have used tubes for butterflies and dragonfles as 3.5 mtrs can be a bit restrictive.
Hi Roy,
I was just adding my thoughts on usage of tubes to what seemed to me the most relevant technical comment on their features: in this way I just wanted to put the two things together in order to give an overall understanding of these tools and to ease reading
Sorry if in any way I hijacked your comment ... 'twas not intentional |:$|
Cheers,
Max

[Roy C]

Hi Roy,
I was just adding my thoughts on usage of tubes to what seemed to me the most relevant technical comment on their features: in this way I just wanted to put the two things together in order to give an overall understanding of these tools and to ease reading
Sorry if in any way I hijacked your comment ... 'twas not intentional |:$|
Cheers,
Max

No problem Max, I agree with you that Extension tubes with the 400mm f5.6 is of little use when photographing birds, I am lucky if I can get within 5 metres.

[bpw]

I use the 12mm tube a lot. The birds aren’t tame in my area either, but I use reserve hides and have my own bag and dome hides that I often carry with me. I also use the tube when photographing garden birds. Before I got the tubes there were many occasions when the bird was too close to focus.

I rarely use the 25mm tube because of the maximum focusing distance of only 6.6m. If the Sparrowhawk lands at the bottom of my garden I can’t reach him with this tube in place.

So, lots of varied opinions about the use of tubes with birds! I suppose it depends on your individual approach to bird photography.

[Ragna]

I regularly use the Canon 12mm extension tube on the 400 5.6L there is no loss of light it still aytofocuses and still maintains auto exposure.Also i am sure that i read somwhere that with the 12mm tube fitted it gives you another 16% magnification.

[bpw]

My understanding is (correct me if I’m wrong) that there is some loss of light with tubes, I think in the region of 1/3 stop with the 12mm tube and 2/3 stop with the 25mm tube (from memory). Unlike with tele-converters, however, the maximum aperture is not affected, but the loss of light is reflected in a change in shutter speed (assuming aperture priority).

[gatafrancesca]

Thanks everybody for your help!
I think that Paul is right: every photographer's technique is different, so different people will use (or not) extension tubes according to their needs. Although I like flowers and insect shots, my main interest is in birds, but I don't think I will be using a hide. Probably the birds won't get that close to me, and if they do, I can always move one step backwards. :) That's why I thought I will begin with the lens alone first, and then decide if I really need an extension tube, based on my own experience.
Still have to wait a few weeks in order to go to the photography equipment dealer and buy the lens, tripod and head. By the way, I decided to go for a Manfrotto 055CLB (cheaper than the NAT3) and a 128RC head. I will also buy a remote shutter release and a 1GB CF card (I only have a 512MB one). I think I will have a lot to learn about my lens when I finally get it!
I'll keep on reading more BF photography threads meanwhile... ;)
Cheers

Francesca Albini
San Cristóbal de Las Casas
Chiapas, Mexico
gatafrancesca@yahoo.com