can one use extenders together

I believe I know the answer, but I wanted to check before I jump on a local deal.

Is it physically possible to directly stack extenders e.g. canon X1.4 III AND canon x2 III
I think I read somewhere that someone added a spacer.... but I can't find that notation again

I understand that there are negative consequences of doing so, but I just wanted to understand if it is possible - and how - if so.

Many thanks

You can stack as many 1.4x and 2x extenders as your tolerance for deteriorating IQ will allow. There is no physical limit, but a 1600mm f/45 lens isn't very useful. OK, maybe for solar eclipses.

Incorrect, as outlined by more knowledgeable folks. Acknowledged.

thanks geokras!
you have a way of putting things that is quite funny.
Many thanks again

and I will be posting my 1600 f45 pictures of complete blur in the artistic blur section...
we have one of thse sections, right?

You can't stack Canon mk III extenders, it's physically impossible.

They are also not compatible with all lenses. Google Canon extender lens compatibility.

i don't think geokras is right in this situation...there are many extenders that don't mount on just any EF mount...so it will actually depend on what extenders your trying to mount to each other

I once stacked 3 M42 2X converters on a M42 200mm, even the slightest wind would sway it so much. I had it on a great tripod and a lens collar and still it had crazy movement. Having it on a crop body didnt help either.

JWdlft wrote in post #17648344
You can't stack Canon mk III extenders, it's physically impossible.

They are also not compatible with all lenses. Google Canon extender lens compatibility.

thanks for this. I am planning to use them potentially with the 100-400 and the 70-200. All the lists mention lenses - but not if they are compatible with each other. Someone mentioned using an extension ring 12mm between the 2 - do you know if that works?

DreDaze wrote in post #17648351
i don't think geokras is right in this situation...there are many extenders that don't mount on just any EF mount...so it will actually depend on what extenders your trying to mount to each other

i am planning the x1.4 and the x2 of canon version 3.

JWdlft wrote in post #17648344
You can't stack Canon mk III extenders, it's physically impossible.

They are also not compatible with all lenses. Google Canon extender lens compatibility.

INCORRECT!

You can stack all Canon EF tele converters. Use a 12mm extension tube between the converters, as I did with my Sigma 2x and Canon 1.4X, the Sigma has protruding elements just like the Canon. Infinity focus is not lost as when using an extension tube between lens and camera.

IMAGE LINK: https://www.flickr.com …323/in/datepost​ed-public/

D43_7740_1280

This is a 3411 pixel crop (of original 4896) with same 1.4x and 2x combo.

ceriltheblade wrote in post #17648372
thanks for this. I am planning to use them potentially with the 100-400 and the 70-200. All the lists mention lenses - but not if they are compatible with each other. Someone mentioned using an extension ring 12mm between the 2 - do you know if that works?

i am planning the x1.4 and the x2 of canon version 3.

Yea, they won't stack - the protrusion from one won't fit into the other. A short extension ring will work, but you lose infinity focus.

Choderboy wrote in post #17648385
Infinity focus is not lost as when using an extension tube between lens and camera.

Are you sure about that? Extension is extension is extension. Certainly on a 70-200 with stacked extenders (either way round) and a tube you'll lose infinity focus. You can focus a long distance away, but you won't get a moon shot for example.

Kenkos will stack without spacers, but that won't help here I guess.

sploo wrote in post #17648391
Are you sure about that? Extension is extension is extension. Certainly on a 70-200 with stacked extenders (either way round) and a tube you'll lose infinity focus. You can focus a long distance away, but you won't get a moon shot for example.

Absolutely, beyond doubt, no question, 100%.

So extension is not extension is not extension in this case.

Google Romy Ocon or Liquidstone (same person). See his results shooting the moon, among other things, with up to 3 Canon TCs, or search POTN for x_tan who has posted examples. etc etc etc

JWdlft wrote in post #17648344
You can't stack Canon mk III extenders, it's physically impossible.

They are also not compatible with all lenses. Google Canon extender lens compatibility.

Choderboy wrote in post #17648385
INCORRECT!

You can stack all Canon EF tele converters. Use a 12mm extension tube between the converters, as I did...

My answer was correct, as in it answered the question:

ceriltheblade wrote in post #17648235
...Is it physically possible to directly stack extenders e.g. canon X1.4 III AND canon x2 III...

That looks really interesting!

Can you tell us a bit more? What lens did you use?
And, what was the rest of your setup? How did you steady the lens?