siggy 1.4 extender + 100-400

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Bob
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does anyone know if this combination would work, have you tried it?
siggy 1.4 extender + Canon 100-400

sigma and canon sites no good as they obviously only recomend their own product

the reason i am asking is because i have a sigma convertor already and am thinking about changing my sigma lens
 
I *think* Cosmix3 used my Sigma x1.4 with his 100-400 & it fitted / worked :)
 
One thing to beware of when using Sigma T/C's on Canon lenses is a colourcast on the images which is likely due to an interaction between the two different types of spectral coatings used on the elements.

Bob
 
it will fit but you'll lose AF unless you want to tape the pins - from what I've seen how well this combo works can be very variable.

:plusone: manual focus only on your 40D with the 100-400mm + 1.4x TC. You would need a 1D series body to retain single point autofocus upto f8.

although wouldn't recommend taping the contacts, you might get autofocus back, but it will damage you lenses mechanics
 
Apologies for hijaking the thread, but will Sigma lenses work with Kenko extenders on a Canon body?
 
:plusone: manual focus only on your 40D with the 100-400mm + 1.4x TC. You would need a 1D series body to retain single point autofocus upto f8.

although wouldn't recommend taping the contacts, you might get autofocus back, but it will damage you lenses mechanics

Hi Pete

Can you expand on this:thinking: I've been using a canon 1.4 with the pins taped for a while now. You've got me worried:shake:

Cheers
 
thanks all for input

not really sounding to promising, colour cast, variable results

it sounds like if i swap siggy 100-300f4 then the extender just as well go and replace it if i need one
 
These shots were taken two days ago, all shots taken hand held but must admit it was a struggle!

this is at 100mm

1/500th
f6.3
ISO 640

100mm.jpg


This is at 560mm using the Sigma 1.4 plus the 100-400mm
1/500th
f8
ISO 640

100400web.jpg


This is 100% crop of the last image,
1/500th
f8
ISO 640

Hope this helps you. :)


100400zoom.jpg
 
My 100-400L with Kenko Pro 1.4x will not AF on a 40D, even when you tape the pins. It's okay up to about 200mm but then the f/number gets too high and it hunts and shunts and won't lock on. It's hopeless.

However, it will AF on my old 350D - poorly, but it works. I know others have found similar with the 40D being unusually intolerant when the f/number goes above f/6.3 or so.
 
Hoppy, have you been on the sherry?

The OP is refering to a Sigma convertor!
 
Hoppy, have you been on the sherry?

The OP is refering to a Sigma convertor!

The Sigma will behave in exactly the same way, as it's a camera function :)
 
I would stay with the Sigma 100-300 and use the TC as you do now as you have at least the option for use it as an f4 lens in low light.

The Canon 100-400 is not a better solution than the Sigma 100-300 and the TC IMHO
 
These shots were taken two days ago, all shots taken hand held but must admit it was a struggle!

this is at 100mm

1/500th
f6.3
ISO 640

100mm.jpg


This is at 560mm using the Sigma 1.4 plus the 100-400mm
1/500th
f8
ISO 640

100400web.jpg


This is 100% crop of the last image,
1/500th
f8
ISO 640

Hope this helps you. :)


100400zoom.jpg

thank you Jim, thats pretty impressive handheld, the main reason for considering the change is for the IS handheld i am struggling, if i put the convertor on then i would use monopod or tripod as i do now.
physically they will combine then which was what i wanted to know
 
I would stay with the Sigma 100-300 and use the TC as you do now as you have at least the option for use it as an f4 lens in low light.

The Canon 100-400 is not a better solution than the Sigma 100-300 and the TC IMHO

its a tough choice to which i have not decided, hand help without the convertor i struggle but then again its more than likely my technique

two reasons for considering 100-400....IS and secondary that little bit of extra length
 
Hi Pete

Can you expand on this:thinking: I've been using a canon 1.4 with the pins taped for a while now. You've got me worried:shake:

Cheers

When a teleconvertor is a 'reporting' type design, it tells the body it is mounted, so that body knows an f/4 lens is really f/5.6. A non-reporting convertor simply is invisble to the body, so that the body merely thinks there is less light coming thru an f/4 lens.

Taping the contacts turns a reporting convertor into a non-reporting convertor.

All that really does is that the body tries to AF, but it is not assurance that the body can actually focus successfully!

It might hunt continuously and burn out the AF motor in the lens, instead.
 
Just to remove any ambiguity from Pete's post above....

The teleconverter switches a contact back to the lens reporting either 1.4 or 2x. The lens then modifies the focal length and maximum aperture that it reports to the body.

The amount of light lost has no real bearing on the ability to AF normally. The difficulty arises at smaller apertures as the angle between the AF sensor pairs becomes too acute for the processor to calculate accurately.

Bob
 
Just to remove any ambiguity from Pete's post above....

The teleconverter switches a contact back to the lens reporting either 1.4 or 2x. The lens then modifies the focal length and maximum aperture that it reports to the body.

The amount of light lost has no real bearing on the ability to AF normally. The difficulty arises at smaller apertures as the angle between the AF sensor pairs becomes too acute for the processor to calculate accurately.

Bob

Good comment from Bob :thumbs:

Basically, taping the pins doesn't mean you will retain AF. It just means the camera will still try to AF, and might manage it, or might not. For the reason Bob says.

As I said earlier, my 40D doesn't have much headroom above f/5.6 and the older 350D has a bit more. Others have found the same and I have no idea why the 40D behaves like this. I wonder what the 7D is like?

In practice, f/6.3 seems to be the limit for AF systems on non-pro bodies. Canon officially says f/5.6 and the system switches off at this level unless it is tricked. However, numerous third party lenses run to f/6.3 at the long end and seem to get away with it by telling porkies to the camera. I'm not sure how good they are at that level though.

The accuracy of phase-detect AF systems (all DSLRs) is more dependent on the physical diameter of the lens aperture than the light level. Contrast-detect systems (all compacts and DSLRs in live view mode) work just as well at any lens aperture, but need good light and an image with some detail in it.
 
As I said earlier, my 40D doesn't have much headroom above f/5.6 and the older 350D has a bit more. Others have found the same and I have no idea why the 40D behaves like this.

It's very possible that, having fewer AF points to fit in, Canon spaced the respected pairs a little further apart....only a guess

Bob
 
Good thought Bob :thumbs:

It would be interesting to see how your 30D, 40D, 50D and 7D compare ;)
 
Good thought Bob :thumbs:

It would be interesting to see how your 30D, 40D, 50D and 7D compare ;)

Perhaps I'll have a play with the first three....the 7D's lying on it's back with the body cap off and being used as a pencil holder :(

Bob
 
Perhaps I'll have a play with the first three....the 7D's lying on it's back with the body cap off and being used as a pencil holder :(

Bob

:eek:

I'm sure that's not what it is supposed to be used for Bob. Are these new 7D's being temperamental? Wassup wiv it?
 
:eek:

I'm sure that's not what it is supposed to be used for Bob. Are these new 7D's being temperamental? Wassup wiv it?

Noise :gag:

I'm trying to figure out why but it seems to be primarily on the red channel. By the time I get the noise cleaned up then cropping is a big no no as too much detail is lost. Test are showing me that the 1D3 will crop to 7D size and have more usable detail ATM. I think there's some underlying issue that affects some but not all 7D's as the reviews from users are very mixed...hero or zero. Maybe sensor batches...optics or amplifier?

I'll report back elsewhere when I suss it out properly.

Bob
 
Noise :gag:

I'm trying to figure out why but it seems to be primarily on the red channel. By the time I get the noise cleaned up then cropping is a big no no as too much detail is lost. Test are showing me that the 1D3 will crop to 7D size and have more usable detail ATM. I think there's some underlying issue that affects some but not all 7D's as the reviews from users are very mixed...hero or zero. Maybe sensor batches...optics or amplifier?

I'll report back elsewhere when I suss it out properly.

Bob

Bob dont know if this is any use but Sara (Swag) sent hers back to Canon because of noise and they are sending her a new one as hers was faulty and had a 'software fault'. :shrug:
 
Bob dont know if this is any use but Sara (Swag) sent hers back to Canon because of noise and they are sending her a new one as hers was faulty and had a 'software fault'. :shrug:

I'm keeping my eye on the outcome of that one Paul although there are many more Sara's in a very similar position. Some sort of announcement from Canon wouldn't surprise me in the least.

Bob
 
I'm keeping my eye on the outcome of that one Paul although there are many more Sara's in a very similar position. Some sort of announcement from Canon wouldn't surprise me in the least.

Bob

I was thinking about Sara too. It'll be interesting to see if her confidence in the 7D is fully restored when her replacement camera arrives.

I'm sure they'll sort it but meanwhile I'm glad I'm not in a rush to get one just yet.
 
Hi Pete

Can you expand on this:thinking: I've been using a canon 1.4 with the pins taped for a while now. You've got me worried:shake:

Cheers

Pete, CanonBob, Hoppy,

Thanks for the clarification:thumbs: The 1.4x (taped) worked OK with my 100-400 and Siggy 500mm with my old 30D. Now thats died prehaps best not to use with the 50D:(
 
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