R3 with EF400mm F2.8+ 2x extender

[justashooter]

As an aside to this conversation, I bought a ProMaster EF - RF mount adapter and filed it out so the R Series Canon extenders would mount. I took my EF 300mm 2.8 II, mounted a EF 1.4x II to it, mounted the adapter, then mounted a RF 2x, then attached it to a R3. The exif data shows both of the extenders, but the math is wrong. It displays as a 420mm. Anything EF attached to the lens is read correctly. It appears as: EF300mm f/2.8L IS II USM +1.4x III + EXTENDER RF2x = 420mm

 

[jo6466]

My last tests
I tried this combinations :
400mm + 2x + Kenko + 1,4x + EF/RF + R3 .... exif = 800mm F/5.6 in reality 1120mm F/8 ... autofocus OK until middle distance
400mm + 1.4x + kenko + 2x + EF/RF + R3 .... exif = 560mm F/4 in reality 1120mm F/8 ... autofocus NOT USEABLE at middle and long distance

Can you explain this difference of autofocus behavior.

 

[neuroanatomist]

My last tests
I tried this combinations :
400mm + 2x + Kenko + 1,4x + EF/RF + R3 .... exif = 800mm F/5.6 in reality 1120mm F/8 ... autofocus OK until middle distance
400mm + 1.4x + kenko + 2x + EF/RF + R3 .... exif = 560mm F/4 in reality 1120mm F/8 ... autofocus NOT USEABLE at middle and long distance

Can you explain this difference of autofocus behavior.

@AlanF made the point above that stacking order matters.

From discussions of 10-15 years ago, which are no longer searchable, I recall vaguely it was said it made a difference to focussing of whether the 1.4x was stacked before or after the 2x.

 

[jo6466]

Pictures test:
I took the same flours at the same distance with the same ISO800 and 1/1000
After this i croped the same partial picture

Here's the results :
400mm only
400mm + 1,4x
400mm + 2x
400mm + 2x + 1,4x

 

[koenkooi]

Pictures test:
I took the same flours at the same distance with the same ISO800 and 1/1000
After this i crop the same partial picture

Here's the results :
400mm only
400mm + 1,4x
400mm + 2x
400mm + 2x + 1,4x

The 400+2x shot seems to have focussed on the flower on the right, not the one in the center.

 

[Frodo]

In a post on the EF 400 DO, I reported on testing the EF 1.4x iii and RF 1.4x (the latter with a modified adapter).
- The EF teleconverter images are a bit sharper and more contrasty than the RF
- DXO PureRaw4 has a profile for the EF 400 DO with EF 1.4x iii teleconverter, but not for the RF teleconverter. PR4 significantly increases contrast and apparent detail of the EF 1.4x image, lifting it well above the RF.
- Both teleconverters report the correct focal length, but only the EF converter corrects the aperture (at least as is visible in Lightroom).

 

[jo6466]

To know if we have today a limit in iso capacity i take this picture in the night at 22h at ISO 102400 - 1/30 ... F/5.6 .. with my R3 + EF400mm F2,8 + EF2xIII ...and denoising after by ON1 RAW IA last version in mode AUTO one click

 

[AlanF]

To know if we have today a limit in iso capacity i take this picture in the night at 22h at ISO 102400 - 1/30 ... F/5.6 .. with my R3 + EF400mm F2,8 + EF2xIII ...and denoising after by ON1 RAW IA last version in mode AUTO one clickView attachment 224298

The R3 has a dynamic range of 2.63 at iso 102,000. So, if you are happy with minimal colour and tonal range and not needing to resolve fine detail, then fine.

 

[jo6466]

The R3 has a dynamic range of 2.63 at iso 102,000. So, if you are happy with minimal colour and tonal range and not needing to resolve fine detail, then fine.

It was only a performance test of R3 and denoise tools
ISO 102400 isn't of course a current use for pictures of quality

 

[jo6466]

An another test :
The same subject take with a R3 and an EF400mm F2,8 alone and an EF400mm F2,8 + EF 2x-III
- same speed 1:2400
- same aperture : F/5,6
- same ISO 320
- same cropping

Left picture = 800mm
Right picture = 400mm

Its clear that the result is better with the EF 2X-III
The EF400mm F2,8 is not dead ... with his EF 2x-III we have a very good 800mm F5,6

 

[jo6466]

Left : the originals 800mm picture
Right : the original 400mm picture

 

[TexPhoto]

Are you guys having a conversation about crazy teleconverter combinations without me?

 

[jo6466]

Are you guys having a conversation about crazy teleconverter combinations without me?


View attachment 224740

I don't understand what you asked?

 

[jo6466]

Last try : EF400mm-F2.8 + EF2xIII + EF1.4xIII + R3
With this assembly we have a 1120mm - F7.1

Left : The cropping result is very good
Right : original picture

 

[kaihp]

Are you guys having a conversation about crazy teleconverter combinations without me?


View attachment 224740

Been there, done that, got the T-shirt: EF200-400mm f/4L 1.4x + EF 2xTC + Commlite + RF 2xTC = 2240mm.

 

[jo6466]

Been there, done that, got the T-shirt: EF200-400mm f/4L 1.4x + EF 2xTC + Commlite + RF 2xTC = 2240mm.

And the result quality?

 

[neuroanatomist]

And the result quality?

Here are mine (with the EF 600/4 II):

RF and EF extenders on the EF 600/4L IS II

After getting both the RF extenders to use with my RF 100-500L, I became curious about whether they would perform better than my EF MkIII extenders when used with my EF 600/4L IS II on my EOS R3. As most will know, the protruding elements of the RF extenders do not fit into the Canon EF-RF mount...

www.canonrumors.com

 

[TexPhoto]

Been there, done that, got the T-shirt: EF200-400mm f/4L 1.4x + EF 2xTC + Commlite + RF 2xTC = 2240mm.

Don't make me whip out the Kenko 3X Teleplus Pro 300. Because I will.

 

[kaihp]

And the result quality?

The EF 200-400mm doesn't seem to like the EF 2xTC together with the internal 1.4x TC.
Combining the two 2xTCs yields good results, but adding the 1.4x TC deteriorates the IQ so I'm not sure if it is worth the trouble to do so, or just upscale/uprez in post.

I happened to take a picture of Saturn, and there would want as long a focal length you can get, due to the "pixels per duck" point (the rings were like 42 px wide at ~800mm)

 

[AlanF]

Don't make me whip out the Kenko 3X Teleplus Pro 300. Because I will.

View attachment 224846

I had an unchipped one of those that worked well. Went quite nicely with the 2xTC to give a 6xTC.