Taped Teleconverter Question

[Roy C]

I have always assumed that the occasional hunting when using say a 1.4 taped tc on a non series 1 camera and f5.6 lens was due to the fact that you are pushing the cameras AF sytem by trying to AF at f8 when the camera what not designed for it. But now I am not so sure as I recently put my taped 1.4 tc on a 70-200 f4 lens and it hunted like mad :eek!: I Took the tape off the tc and the lens AF'd sweetly as you would expect as it is still only f5.6.
So what exactly causes this hunting ?

[GYRob]

i think its to do with the light when your at f8 but when at f5.6 with the tape on the camera is NOT getting the info on what lens/ apeture is on so henc the hunting.
Rob.

[postcardcv]

I'm not sure what the cause of this is but have had similar experiences... I use a 1.4x (with pins taped) on my Sigma 500 f4.5, it works very well and almost never hunts. However when I put the tc on a Sigma 100-300 f4 it hunted wildly, when I took the tape of it worked fine. I did wonder why, so I hope someone comes up with the answer.

[David Smith]

What I can't my head around (and I'm sure there is a very obvious answer) is
If the pins have to be taped for the af to work-what are the pins actually for i.e. if it doens't work with the pins open and it does with the pins taped then why have them at all ?

[CORVUS1]

I have a Canon D20 with a 100-400 Canon lens, with the 2xTC I have the same prob with hunting. Any ideas ???

[postcardcv]

What I can't my head around (and I'm sure there is a very obvious answer) is
If the pins have to be taped for the af to work-what are the pins actually for i.e. if it doens't work with the pins open and it does with the pins taped then why have them at all ?

from what I can gather the pins that are taped are the ones that 'tell' the camera that you are using a tc. By taping them the camera cannot 'see' the tc so it does not reduce the max aperture, which is handy as Canon bodies (exclusing 1 series) will not even attempt to AF with a max ap smaller than f5.6.

[Roy C]

What I can't my head around (and I'm sure there is a very obvious answer) is
If the pins have to be taped for the af to work-what are the pins actually for i.e. if it doens't work with the pins open and it does with the pins taped then why have them at all ?
David, You will note that when you tape the pins the apperture showing on your Camera and in the Exif data is still f5.6 BUT it is not f5.6 it is really f8, you have fooled the camera into not knowing a tc was present. Had you not taped the pins then there is no way that the Camera will AF - it is impossible because your Camera will not AF at f8 (series 1 Canons will, which is why you have not got to tape the pins with these).

Update : Pete beat me to it.

[GYRob]

something to bere in mind is IF your getting a LOT of hunting it's not doing the lens much good as it's making it work to hard.
Rob.

[Roy C]

I have a Canon D20 with a 100-400 Canon lens, with the 2xTC I have the same prob with hunting. Any ideas ???
With a 2x tc you are effectively shooting at f11 - with your Camera AF will be near impossible at f11 (it is not meant to AF at f8, but you can just about get away with it by fooling the Camera).

[Roy C]

I'm not sure what the cause of this is but have had similar experiences... I use a 1.4x (with pins taped) on my Sigma 500 f4.5, it works very well and almost never hunts. However when I put the tc on a Sigma 100-300 f4 it hunted wildly, when I took the tape of it worked fine. I did wonder why, so I hope someone comes up with the answer.
This is Exactly my point Pete - this cannot be anything to do with light as the f4 with a 1.4 tc is letting in the same amount of light regardless of if the pins are taped or not.

[Keith Reeder]

Roy,

you use the Canon TC, yeah?

I've been discussing a very similar issue on POTN and it would appear that the Canon TC is much more prone to hunting than the Kenko.

I'll say again that hunting isn't an issue for me with the Kenko on my 100-400 - in fact, just last weekend I was shooting stonechats (the most recent ones in my galley).

Light was awful (I was on 800 ISO and had the lens wide open) and yet noticed several times that AF lock-on was literally instant, so I can only assume that - bizarrely - the problem lies in the design of the Canon TC.

Of course, male stoneys aren't bad for contrast, so maybe that helped?

David,

the pins are what the lens communicates aperture (and other stuff, presumably) to the camera through.

xxD Canon bodies are designed to switch off AF when the wide-open aperture of a lens is less than f/5.6 (an f/5.6 lens is f/8 when a 1.4x TC is in place), and that information goes through those pins.

By preventing the pins from contacting the camera, it doesn't know that the lens is at f/8 and tries to AF - with varying dgrees of success, it would seem!

;)

Corvus,

I don't think I've read of anyone being able to successfully AF with a 2x on a 100-400 - maybe that's simply a step too far.

[stevo]

Am I right in saying though that on a Kenko pro 1.4tc the pin that communicates aperture value is missing?Thus allowing the camera to AF above f5.6

Steve.

[Roy C]

Am I right in saying though that on a Kenko pro 1.4tc the pin that communicates aperture value is missing?Thus allowing the camera to AF above f5.6

Steve.
No - the pins are there and need taping (but it depends on what lens you are using of course).

[Roy C]

Roy,

you use the Canon TC, yeah?

I've been discussing a very similar issue on POTN and it would appear that the Canon TC is much more prone to hunting than the Kenko.

.
Hi Keith, It may well be that the Kenko hunts less than the Canon but I have no real problem or concern as I do not find hunting is to bad with my 400mm prime and the 1.4. Only last evening I was shooting Raven's on ISO 1600 at 1/250 sec with virtually no hunting at all. What I cannot understand is why my 70-200 f4 hunts like mad with a tc (a darn sight more than the 400mm lens) and yet without the tape works great with a tc.

[Keith Reeder]

Errrk, I went off at a tangent there!

I still wonder though if the way the Canon TC does things is the problem...

[Roy C]

Errrk, I went off at a tangent there!

I still wonder though if the way the Canon TC does things is the problem...
Just read the thread on POTN Keith. I look forward to seeing the results the guy gets with the Kenko which he is swapping with a friend this weekend. If he is suitable impressed I will get a Kenko Pro (and keep my Canon 1.4 for when I get my 600mm f4 ;) ;) ;) ;) ;) )

[Keith Reeder]

To be fair Roy, if he does report back favourably he'll only be confirming what I'd told him about the Kenko..!


;) ;) ;)

[Roy C]

To be fair Roy, if he does report back favourably he'll only be confirming what I'd told him about the Kenko..!


;) ;) ;)
True Keith but he will have tried both converters as a direct comparison whereas people who have only got one of the tc's tend to vary in their experiences.

[Keith Reeder]

Just having a bit of fun there, Roy..!

;)

[mjmw]

If a lens is f4 or faster (i.e. more light) I think the camera's AF works faster (i.e. tries to focus faster) so if the camera does not know that there is a teleconvertor there, it will still try to focus as if it had f4 of light not f5.6 - hence increased hunting.

If I am correct, then I don't think that the Kenko will solve your problem Roy. It is how the camera's AF responds to the reported aperture (the AF is seperate to the meter which measures actual light).

With regard to the Canon convertors hunting but not Kenko (POTN thread) - I wonder if they send extra data to the camera AF?

[Roy C]

If a lens is f4 or faster (i.e. more light) I think the camera's AF works faster (i.e. tries to focus faster) so if the camera does not know that there is a teleconvertor there, it will still try to focus as if it had f4 of light not f5.6 - hence increased hunting.

If I am correct, then I don't think that the Kenko will solve your problem Roy. It is how the camera's AF responds to the reported aperture (the AF is seperate to the meter which measures actual light).

With regard to the Canon convertors hunting but not Kenko (POTN thread) - I wonder if they send extra data to the camera AF?
All sounds reasonable to me Mark, you could be right about the f4.

[Roy C]

To be fair Roy, if he does report back favourably he'll only be confirming what I'd told him about the Kenko..!


;) ;) ;)
Just read the feedback on POTN Keith - seems fairly positive. Although he has a different lens to me I guess it would still have the same effect on the prime. The one thing I cannot do very well with the Canon tc is BIF and if a Kenko could help me with this it would be worth it to me.
I have a few questions about the Kenko.
Is the Teleplus Pro 300 DG the same animal ?
I have seen both black and white ones - are they both the same tc?
Best price I can see is £99, anyone know of any better deals at the moment?

Cheers
Roy C

[tdodd]

I placed an order for a "KENKO Pro 300 1.4X 1.4 DG Teleconverter Converter(CANON)" with UR-Galaxy in Hong Kong last week. I'm hoping for delivery on Monday. Price was £69 including delivery and with a "no VAT" guarantee stated in the item descripton (but not the item title). I've bought from them once in the past with no problem.

http://cgi.ebay.co.uk/KENKO-Pro-300-1-4X-1-4-DG-Teleconverter-Converter-CANON_W0QQitemZ230143363997QQihZ013QQcategoryZ4687 QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

There's a guy called "Lightrules" on POTN and pbase, who has performed several back to back lens reviews and he rates the Kenko 1.4X highly. Apparently the DG one is the newer version, and black, while the non-DG is older and white (nice with "L" glass). In terms of performance there is supposed to be nothing to chose between them. Have a look at this thread - http://photography-on-the.net/forum/showthread.php?t=313294 - complete with a nice picture of the white finish.

[Keith Reeder]

I still struggle with BIFs when the Kenko is on, Roy - but I'm happy enough with the trade-off because I'm not addicted to BIFs.

I still get it right sometimes though..!

Yep, the Teleplus Pro 300 DG is the kiddy. I believe the colour difference is purely cosmetic (mine's black).

£99 is as good as any UK price I've seen, Roy - I paid £130 from Fotosense: it was in stock with them, and I needed it quickly.

Maybe worth asking Ian Kerr for a quote?

[Roy C]

I still struggle with BIFs when the Kenko is on, Roy - but I'm happy enough with the trade-off because I'm not addicted to BIFs.

I still get it right sometimes though..!

Yep, the Teleplus Pro 300 DG is the kiddy. I believe the colour difference is purely cosmetic (mine's black).

£99 is as good as any UK price I've seen, Roy - I paid £130 from Fotosense: it was in stock with them, and I needed it quickly.

Maybe worth asking Ian Kerr for a quote?
Just read on another site of a guy who has the 400mm f5.6 and Kenko Pro 300 and this is his comment:
"I use the Kenko with my 400mm Roy and the AF hunts a lot, although I've never tried the Canon converter. It needs a very contrasty subject and a bit of patience."
Now I am totally confused :eek!: :eek!: :eek!:

[Keith Reeder]

Hmmm...

What body is he using, Roy?

Maybe (and I'm just putting this out there - not looking for another "zoom vs prime" argument) the 100-400 is simply better than the prime with the Kenko TC?

I think you're going to have to borrow a Kenko from someone and have a go yourself, Roy.

[Roy C]

Hmmm...

What body is he using, Roy?

Good point Keith, I will find out (I know the 30D is much better than the 350D with the tc on board).

[Roy C]

Hmmm...

What body is he using, Roy?


He is using a 400D Keith - is this the same AF system as the 30D?

[Keith Reeder]

Same sensor set up, according to DPReview:

Nine point Auto Focus sensor (same as EOS 30D) with F2.8 support

But then you have to wonder if the 30D delivers more current to the lens than the 400D - that might explain differences in performance...

[Keith Reeder]

Roy,

seen "Nicksan's" comment now that he's got the Kenko?

I can tell you that with the Kenko, it's infinitely better [than the Canon]... it'll hunt on occasion, especially when it cannot find enough contrast. But then the 100-400 w/o TC would also hunt...albeit more mildly.

[Roy C]

Roy,

seen "Nicksan's" comment now that he's got the Kenko?

I can tell you that with the Kenko, it's infinitely better [than the Canon]... it'll hunt on occasion, especially when it cannot find enough contrast. But then the 100-400 w/o TC would also hunt...albeit more mildly.
Yes Keith - I told you that I had seen it this morning :t:
Only problem I have is that from the sound of it "Nicksan" had far more problems with the Canon and 100-400 than I have ever had with the 400 prime so maybe he is now back up to the same level of hunting that I get with the Canon (certainly sounds like it). I would love to hear from a user who has the same set-up as me (Lens and Camera) and has tried both converters.
There seems to be a lot of conflicting reports on these f5.6 lenses with converters - Some people get on fine and yet others with exactly the same set-up say it is almost unusable. Like you say Keith, I don't think I will find out until I get hold of a Kenko and try for myself.

[Keith Reeder]

Lost me there, Roy - Nick seems happy with the performance of the lens, with and without the Kenko...

Are we looking at different threads?

;)

Oh, and he only posted the comment I quoted at 6pm, so unless you've recently upgraded to an "L" glass crystal ball, you can't have referred to it this morning..!

http://photography-on-the.net/forum/showpost.php?p=3387577&postcount=41

;) ;) ;)

[Roy C]

Lost me there, Roy - Nick seems happy with the performance of the lens, with and without the Kenko...

Are we looking at different threads?

;)

Oh, and he only posted the comment I quoted at 6pm, so unless you've recently upgraded to an "L" glass crystal ball, you can't have referred to it this morning..!

http://photography-on-the.net/forum/showpost.php?p=3387577&postcount=41

;) ;) ;)
Looks like I must have been looking at a different thread this morning then Keith - I will take another Gander.

[Roy C]

Lost me there, Roy - Nick seems happy with the performance of the lens, with and without the Kenko...

Are we looking at different threads?

;)

Oh, and he only posted the comment I quoted at 6pm, so unless you've recently upgraded to an "L" glass crystal ball, you can't have referred to it this morning..!

http://photography-on-the.net/forum/showpost.php?p=3387577&postcount=41

;) ;) ;)
You had me worried for a while Keith, I thought I had really lost the plot:'D . I was referring to his post of 02.40 am this morning (post #24). Don't tell me you actually went to bed last night and missed it ;) ;) ;)

[Roy C]

As Keith says the only way I will know how the Kenko works with my set-up is to try one so I have ordered one from UR-Galaxy (£69 inc postage - thanks to 'tdodd').
It will be no big deal if it turns out to be no better than the Canon - I could always stack the two 1.4's and my teleplus 2x ;) ;) ;) ;)

[shoshone]

Roy,

seen "Nicksan's" comment now that he's got the Kenko?

I can tell you that with the Kenko, it's infinitely better [than the Canon]... it'll hunt on occasion, especially when it cannot find enough contrast. But then the 100-400 w/o TC would also hunt...albeit more mildly.

Well I bought the Canon 1.4x TC and on my first trip out with it yesterday it was terrible. I missed so many shots because it was hunting so much and it never locked on before the bird was gone.

Granted the sky was overcast however I don't consider I was exactly trying to push its limits. Take the heron at 50ft...hardly rocket propelled eh....lock on nada. If I listen and watch you can see it focussing either side of dead on and after about 6-8 diminishing movements it makes it...this of course is not panning with a bird in flight. It seems worst at 400mm the end I need :C

Without this TC on my 5D and 100-400 IS L zoom locks on almost immediately.

I tried 'one shot' and 'AI Focus' various ISOs etc no difference. No tripod, all hand held with both IS1 & 2.

This is a big disappointment. Any tips folks? Or is it going to be 'I told you so' :-C

Jamie

[Roy C]

Well I bought the Canon 1.4x TC and on my first trip out with it yesterday it was terrible. I missed so many shots because it was hunting so much and it never locked on before the bird was gone.

Granted the sky was overcast however I don't consider I was exactly trying to push its limits. Take the heron at 50ft...hardly rocket propelled eh....lock on nada. If I listen and watch you can see it focussing either side of dead on and after about 6-8 diminishing movements it makes it...this of course is not panning with a bird in flight. It seems worst at 400mm the end I need :C

Without this TC on my 5D and 100-400 IS L zoom locks on almost immediately.

I tried 'one shot' and 'AI Focus' various ISOs etc no difference. No tripod, all hand held with both IS1 & 2.

This is a big disappointment. Any tips folks? Or is it going to be 'I told you so' :-C

Jamie
Jamie, I am convinced that the Canon 1.4 tc (taped) effects zooms more than primes. My 70-200 f4 is absolutely terrible with the taped tc (not that I need to tape on a f4) but my 400mm f5.6 prime locks on 90% of the time with no problems.
But to be fair you do need good light to test your set-up because your Camera (and all other non 1 series) was only meant to AF at f5.6.
Having said that there are a few things that I use to good effect:
1. Use the full time manual focus to get roughly in focus and then let the AF finish the job.

2. When the hunting starts, release the shutter button and depress again - sometime it will lock right on using this method.

[shoshone]

Jamie, I am convinced that the Canon 1.4 tc (taped) effects zooms more than primes. My 70-200 f4 is absolutely terrible with the taped tc (not that I need to tape on a f4) but my 400mm f5.6 prime locks on 90% of the time with no problems.
But to be fair you do need good light to test your set-up because your Camera (and all other non 1 series) was only meant to AF at f5.6.
Having said that there are a few things that I use to good effect:
1. Use the full time manual focus to get roughly in focus and then let the AF finish the job.

2. When the hunting starts, release the shutter button and depress again - sometime it will lock right on using this method.

Thanks Roy, Looks like your method 2 is an automated method 1 and could be quicker at getting nearly there. I'll try releasing the shutter button and see if I get any success..I'll let you know.

Jamie

[Keith Reeder]

I reckon we need to organise The Great BF Converter Test-In!

How about Salthouse at the beginning of September? Many of us will probably be there anyway..!

;) ;) ;)

[postcardcv]

I reckon we need to organise The Great BF Converter Test-In!

How about Salthouse at the beginning of September? Many of us will probably be there anyway..!

not the best place for the test, if you're at Salthouse in September you will have better things to do then test one tc against another...

I think one important thing to remember is that when using a 1.4x tc (with pins taped) with either the 100-400 or the 400 f5.6 on a non 1 series body, you are trying to make the camera do something it's not designed to do. So I guess we shoud lbe pleases when it works, not annoyed when it doesn't. There really is little reason to it (as far as I can see), just seems to be a matter of buying one and trusting to luck! I have seen identical set ups side by side where one works fine with a tc and the other doesn't.

[shoshone]

Jamie, I am convinced that the Canon 1.4 tc (taped) effects zooms more than primes. My 70-200 f4 is absolutely terrible with the taped tc (not that I need to tape on a f4) but my 400mm f5.6 prime locks on 90% of the time with no problems.
But to be fair you do need good light to test your set-up because your Camera (and all other non 1 series) was only meant to AF at f5.6.
Having said that there are a few things that I use to good effect:
1. Use the full time manual focus to get roughly in focus and then let the AF finish the job.

2. When the hunting starts, release the shutter button and depress again - sometime it will lock right on using this method.

Roy, Today was a better day for testing (brighter and sunnier than yesterday). I tried your ideas and I don't think I got method 2 right...though I will keep trying. Method 1 seemed to work better. However abject failure when trying to focus on a moving bird whilst panning. I have to say that today the AF locked on to stationary objects almost first time but on the wing nope.

Any ideas on the following please? Previously without the 1.4x TC on, I often had to focus on the bird at say 200mm and then pull it in whilst trying to stay on the bird. Now that I'm viewing at 560mm instead of 400mm I'm beginning to think it unreasonable of me to try to lock on to the subject with the 100-400 fully extended (as I have been trying to do since I got the TC --expecting miracles?...maybe) and maybe starting at 200mm each and every time then pulling it in to 400 (560mm) might work.

Today in my rather unscientific tests however I didn't have enough sky available to lock on and pull the bird in trying this. The point is that working at effectively 560mm could perhaps take a lot more practise perhaps? If so then I'm starting to realise that folks with a 1.6 crop factor and a 1.4x TC on a 100-400mm lens @ 400mm (effectively 896mm) would have one heluva job to track and focus on anything? Anyone in this situation find this easy??

cheers
Jamie

[Roy C]

Roy, Today was a better day for testing (brighter and sunnier than yesterday). I tried your ideas and I don't think I got method 2 right...though I will keep trying. Method 1 seemed to work better. However abject failure when trying to focus on a moving bird whilst panning. I have to say that today the AF locked on to stationary objects almost first time but on the wing nope.

Any ideas on the following please? Previously without the 1.4x TC on, I often had to focus on the bird at say 200mm and then pull it in whilst trying to stay on the bird. Now that I'm viewing at 560mm instead of 400mm I'm beginning to think it unreasonable of me to try to lock on to the subject with the 100-400 fully extended (as I have been trying to do since I got the TC --expecting miracles?...maybe) and maybe starting at 200mm each and every time then pulling it in to 400 (560mm) might work.

Today in my rather unscientific tests however I didn't have enough sky available to lock on and pull the bird in trying this. The point is that working at effectively 560mm could perhaps take a lot more practise perhaps? If so then I'm starting to realise that folks with a 1.6 crop factor and a 1.4x TC on a 100-400mm lens @ 400mm (effectively 896mm) would have one heluva job to track and focus on anything? Anyone in this situation find this easy??

cheers
Jamie

Good to see you had a better day Jamie. Birds in flight are always going to be most difficult with taped converter on board. I have not got the 100-400 zoom so cannot give any advise on techniques with this lens but from the method you give I assume that you use A1Servo mode !.
Even with my 400mm f5.6 prime which has got lightening fast AF on the bare lens and is know as a superb In-Flight lens I find this very difficult with a taped converter (this is the reason why I want to try a Kenko pro ).

[shoshone]

Good to see you had a better day Jamie. Birds in flight are always going to be most difficult with taped converter on board. I have not got the 100-400 zoom so cannot give any advise on techniques with this lens but from the method you give I assume that you use A1Servo mode !.
Even with my 400mm f5.6 prime which has got lightening fast AF on the bare lens and is know as a superb In-Flight lens I find this very difficult with a taped converter (this is the reason why I want to try a Kenko pro ).

Hmmn...I'll look avidly for your opinion on the Kenko then.....I thought that was coffee B (:

Keep us posted won't you, as I guess with 20:20 hindsight if it works great I could still probably come away with some change as the Canon 1.4x seems to have a high resale value ;)

[Keith Reeder]

BIFs with the 100-400 + Kenko are very hard work.

[paul goode]

BIFs with the 100-400 + Kenko are very hard work.

I'd add a couple more 'verys' to that Keith. Tried planes in flight with the tc at an Airshow at the weekend and very quickly abandoned that idea!

Paul

[tdodd]

I placed an order for a "KENKO Pro 300 1.4X 1.4 DG Teleconverter Converter(CANON)" with UR-Galaxy in Hong Kong last week. I'm hoping for delivery on Monday. Price was £69 including delivery and with a "no VAT" guarantee stated in the item descripton (but not the item title). I've bought from them once in the past with no problem.
I'm pleased to say that my Kenko 1.4X converter arrived this morning, safe and sound, along with Kenko extension tubes and an EF 10-22 lens with extended warranty, and no hit for VAT :)

[tdodd]

I'm afraid I don't have any birds in shot but here is a quick series of test shots with the 1.4X teleconverter and my EF 50mm f/1.8 MKII lens. This is the only EF lens I have at the moment. My EF-S lenses will not fit due to the protruding rear of the lens. I'm hoping for some long EF glass to arrive tomorrow.

These are 100% crops from photos taken on a braced (but not completely steady) monopod. The subject is about 250-300m away. Exif data is included. The shots are at f/1.8, f/2.8, f/4.0, f/5.6, f/8.0. I also shot at f/11 and f/16 but can't attach those shots due to the 5 attachment limit. f/11 still looks pretty good, although a little soft, while at f/16 there is a noteable softening, possibly due to slowish shutter but more likely through diffraction. I didn't tape any pins, yet there was no change to the perceived aperture when adding the telecon - f/1.8 appeared still to be available, even though it wasn't. The f/stops quoted are thus the uncorrected f/stops. The images were shot in raw and cropped and converted using Lightroom. I did not apply any sharpening or other processing beyond the standard defaults for Lightroom.

Autofocus took a couple of wriggles in single shot mode before locking in OK most of the time. On AI Servo the lens would chatter away, sometime locking but mostly not. Mind you, the EF 50mm f/1.8 is hardly reknowned for its great AF performance.

[shoshone]

I'd add a couple more 'verys' to that Keith. Tried planes in flight with the tc at an Airshow at the weekend and very quickly abandoned that idea!

Paul

Ouch! No GIFs of BIFs or PIFs :-C

kinda severely impales the ideas I had for using my new Canon TC 1.4x :eek!:

So TC's are relegated to BARs then? (Birds @ Rest)

Jamie
:C

[Roy C]

I'm afraid I don't have any birds in shot but here is a quick series of test shots with the 1.4X teleconverter and my EF 50mm f/1.8 MKII lens. This is the only EF lens I have at the moment. My EF-S lenses will not fit due to the protruding rear of the lens. I'm hoping for some long EF glass to arrive tomorrow.

These are 100% crops from photos taken on a braced (but not completely steady) monopod. The subject is about 250-300m away. Exif data is included. The shots are at f/1.8, f/2.8, f/4.0, f/5.6, f/8.0. I also shot at f/11 and f/16 but can't attach those shots due to the 5 attachment limit. f/11 still looks pretty good, although a little soft, while at f/16 there is a noteable softening, possibly due to slowish shutter but more likely through diffraction. I didn't tape any pins, yet there was no change to the perceived aperture when adding the telecon - f/1.8 appeared still to be available, even though it wasn't. The f/stops quoted are thus the uncorrected f/stops. The images were shot in raw and cropped and converted using Lightroom. I did not apply any sharpening or other processing beyond the standard defaults for Lightroom.

Autofocus took a couple of wriggles in single shot mode before locking in OK most of the time. On AI Servo the lens would chatter away, sometime locking but mostly not. Mind you, the EF 50mm f/1.8 is hardly reknowned for its great AF performance.
The test will come if you try to use the tc with a f5.6 lens - then you will have to tape the pins to achieve AF as your Camera will not AF at f8.

[tdodd]

The test will come if you try to use the tc with a f5.6 lens - then you will have to tape the pins to achieve AF as your Camera will not AF at f8.

My 100-400 arrived this afternoon :-O

AF is as dead as a dodo with the pins untaped as aperture goes from f6.3 and smaller and, like you say, will not work wth my 30D. With the pins taped the AF comes in just fine. I can't get any BIF shots where I am at the moment as the little blighters are far too quick for me to even swing the lens into position, much less acquire focus and track them.

What I have done is shoot another series of shots of my long distance sharpness test target at 400mm without the teleconverter added. I have included the full image, albeit resized, and a 100% crop at each f/stop from f/5.6, f/8, f/11, f/16, f22. I've then repeated the shots with the teleconverter, at the same aperture openings, but of course, adjusted by the addition of the telecon to become f/8, f/11, f/16, f/22, f/32. I should add that with the tecon attached I was using MF rathe than AF as I had not yet taped the pins. Maybe AF would have done a better job of focusing.

As there are 20 images in all I have put them in a little web album, here....

http://picasaweb.google.co.uk/EezyTiger/CanonEF100400PlusKenko14XTeleconverter?authkey=8lg kcIyuGQE

[tdodd]

I still haven't been out to hunt down BIFs but here are a couple of static shots with the 100-400 at 400mm and the Kenko 1.4X extender with taped pins. Factoring in the 1.6 crop factor of the 30D that's equivalent to 896mm !!!

Both shots were hand held at 1/60 second, f/5.6 (= f/8 with the teleconverter), with flash, at 800 ISO. Due to the height of the bird I could not brace my arms against my body so it was very hard to grab perfectly sharp shots and the focus was sometimes stubborn. Stiil, I think the results are not too bad. Thank heavens for IS :) These photos are uncropped and unedited, just resized....

[gmax]

They look good, given the conditions

[mjmw]

This same question came up on another thread - I have just written a long post there which covers many of the questions asked on this thread...in case anyone is interested ;)

Rather than repeat the post here it is #30 on this following thread.

http://www.birdforum.net/showthread.php?t=89438&page=2

[tdodd]

At long last I have secured some BIF shots with my Canon 30D and EF 100-400 with Kenko 1.4X teleconverter. I have posted several examples here....

http://picasaweb.google.co.uk/EezyTiger/BIFWithCanon30DEF100400Kenko14XTeleconverter?authk ey=jGvbGyOyklE

I have very little experience at BIF shots and I have to say I am pretty unimpressed with the results. It could be the equipment combination but it is probably something I was doing wrong. For reference I have included two benchmark test shots (100% crops) of a TV aeriel, first shot with a tripod and secondly hand held.

The bird photos are crops taken at 1169*780 from the original 3504*2336 image, simply because the birds were often quite small in the frame, and then reproduced at 50% magnification to produce 584*389 pixel 50% crops. I have not applied any sharpening.

I was using IS mode 1 for all the shots, which is not the panning mode. I wonder if this was part of the problem. I could only get focus lock and tracking with the centre AF point and this was only successful on the gulls. When I tried it a a rook/crow flying past I could not get a lock. Using multi-point AF the camera would not lock at all and left the image completely blurred - not even close.

Any advice or comments would be gratefully received.

Here's a couple of the better samples....

[tdodd]

For completeness I've also uploaded an album of the uncropped and unedited photos here....

http://picasaweb.google.co.uk/EezyTiger/BIFUncroppedFullSizeFilesConvertedFromRawAt70Quali ty?authkey=YSvtoI1ymKo

Click a thumbnail to see a larger image and then click "Download Photo" to get a full sized jpeg file.

[Paul Jarvis]

As a newbe to the dslr world I have been reading this thread with great interest, and now become completely confused. Is taping the pins recommended and if so how do you do it without causing damage?

I have the 400d, 70-300 IS and 1.4 kenko tc, I have been expriencing alot of violent shaking when I try to focus on a bird with the tc. Is this the hunting as some refer to or something else?

I have attached 2 pics the one on the left is without the tc and the right one is with. I have come to a conclusion that a tc should only be added for say a record shot where the lens on its own is'nt long enough due to the degrade in image quality. (This is just my own oppion as well).

To me they both seem acceptable but the one on the left looks to have the edge. They are both resized to 100%.

Thanks for your patience in advance if anyone might have a solution for my problem.

[Keith Reeder]

T,

it is very hard to get really sharp BIFs with the 100-400 and and TC - it is just very hit-and-miss.

[tdodd]

A Canon 1 series camera will autofocus with lenses of f/8 or faster. A non 1 series camera will only autofocus with a lens of f/5.6 or faster. If you add a 1.4X teleconverter it effectively reduces the speed of the lens by 1 stop, so an f/5.6 lens effectively becomes f/8 as far as the autofocus is concerned. When you add the teleconverter the pins tell the camera that the lens speed has been reduced and the camera will refuse to autofocus. By taping three of the pins you break the connection and the camera is unaware that a teleconverter is attached. Thus the camera will still attempt to autofocus, even though it is operating outside its designed parameters.

For some people/camera/lens combinations this trick works more or less OK, in ideal lighting conditions. If the light/contrast is poor or you are simply one of the unlucky ones the AF will hunt like mad and probably fail to focus accurately. Whether you can damage your equipment like this I do not know but it is probably better to accept the equipment limitations if it does not work properly for you.

If taping the pins works for you then leave them taped. If it doesn't work then you are better off removing the tape and using the kit as it was designed. This will give the added advantage that your exif data will be reported correctly with adjustments to f-stop and focal length.

[Roy C]

As a newbe to the dslr world I have been reading this thread with great interest, and now become completely confused. Is taping the pins recommended and if so how do you do it without causing damage?

I have the 400d, 70-300 IS and 1.4 kenko tc, I have been expriencing alot of violent shaking when I try to focus on a bird with the tc. Is this the hunting as some refer to or something else?
.

Paul, you do not need to tape the tc with your lens because your lens has not got the pins to pass the info to the tc anyway. Converters are more suited to some lenses than others and canon do not think your lens is ideally suited to a teleconverter which is why you can AF (of a sort) without taping the pins (double dutch I know). The violent shaking you refer to is 'hunting' and taping the pins would not make any difference to you.
On Canon lenses that are recommended for use with a tc they have extra pins on the lens which sends a signal to the camera to tell it there is a tc present, with a non 1 series body you have to tape the pins in order to AF if the max aperture is f5.6 as it becomes f8 with a 1.4 tc.
P.S If you had a Canon converter it would not even fit your lens

[Paul Jarvis]

Thanks guys your help is much appriecated.

[Keith Reeder]

Paul, taping the pins isn't so much "recommended" as required to maintain AF with some lenses/cameras.

The shaking you mention does sound like hunting.

There doesn't seem to be a huge difference in IQ between the two pictures, but it has to be borne in mind that TCs just don't perform brilliantly with some lenses and some cameras - I've seen reports on here that the 400D can really struggle with a TC; and your lens might not really suit a TC - although this seems pretty positive: http://www.bobatkins.com/photography/reviews/ef_70_300is_review.html

With a Tamron 1.4x TC, there's good news and there's bad news.

The good news is that image quality with the TC attached to the new 70-300 lens at 300mm (=420mm with TC) is pretty good - significantly better than with the old lens - but not as good as with the 300/4L of course.

The bad news is that the faster focus of the new lens results in focus hunting and oscillation with the Tamron TC attached. The lens isn't supposed to AF at all at f8 on an EOS 20D of course, so you can't really complain, but the old lens would actually AF quite well with the Tamron 1.4x attached (due, presumably, to the slower AF).

All is not lost though since the electronic focus confirmation (beep and green dot) does work, so you don't have to depend 100% on your eyesight in MF with the TC. The Canon TCs, of course, do not physically fit on this lens.

[Paul Jarvis]

Thanks Keith interesting reading from that reveiw and explains a great deal to me.