Stacked 1.4x and 2.0x TC III for astrophotography

Started 8 months ago | Discussions thread
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Rey66 Senior Member • Posts: 1,428
Stacked 1.4x and 2.0x TC III for astrophotography

So, I did some test for the heck of it between Sony body and Canon Body.
1.4xTC III + 2.0x TC III + 400mm F4 DO II = 11200mm F11.2?

Sony A7R3 with MC-11: It will NOT acquire focus at all even though the aperture shows F5.6(1.4x first closer to the body). So we are stuck with manual focus.
Canon 5D IV:
Will not focus when using optical viewfinder BUT when I switched to live view it quickly focused! So I think I am going to try to use this combo for astrophotography and will test infinity focus, I read it somewhere that it is possible to focus at infinity even there is a 12mm ext tube. Will see if its true. Sony looks more longer due to the adapter. BTW, the live view tracking on the 5D IV works flawlessly and it is like no TC attached to it.

 Rey66's gear list:Rey66's gear list
Canon EOS 5D Mark IV Sony a7R III Canon EF 200mm f/2L IS USM Canon MP-E 65mm f/2.5 1-5x Macro Canon Extender EF 1.4x III +4 more
Canon EOS 5D Mark IV
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