Why no mirror telephotos for DSLR Canon?

Started Jan 25, 2010 | Discussions thread
jpr2 Forum Pro • Posts: 15,410
re: it would be quite a revolution

RobertSigmund wrote:

Wow - time to get one and either reactivate my minolta film slrs
or buy a sony dslr.

no doubt in-body IS must play a role here, but above all if we consider
how it is possible to AF a f/8 lens using standard PD sensors... it would
mean quite a revolution should Canon decide to build such a f/8 CAT.
There are f/5.6 500mm Rubinars but they are loosing all benefits of
being light and small (Minolta-Sony 600/8 is quite tiny).

I've old 500/8 mirror, bought over 20 yrs. ago - it is a typical no brand,
el-cheapo lens, and yet... when focused carefully it can hold it's own,
even with 2x and 1.4x teleconverters:

all shots taken with 40D, ISO 400 (focused with LV, 550EX sync.at
1/250 sec was used to freeze any motion)

top row (from the left):

  • 1) at the native 500mm f/8,

  • 2) for comparison purposes - EF 300/4L IS + 2x mkII TC (painted black, see just below),

  • 3) cat 500/8 + 1.4x pro300dg of Kenko.

bottom row (from the left):

  • 4) 100% crop of the native 500 f/8,

  • 5) how does 1000mm look like: 500/8 CAT with the 2x mkII and lens hood on 400D, (there is a 12mm ET together with M42 to EF-mount adapter equipped with a confirm chip between the cat, and 2x TC) - notice how small the cat is in comparison to this 2x TC,

  • 6) cat 500/8 + 2x mkII TC;

panels 1-3) and 6) are resized in the same way; so, they can be
compared between all four;
panel 4) is the actual 100% crop of the panel 1) - before resizing
of course

street candids (non-interactive):
music and dance:
wildlife & macro:
interactive street:

Comments and critique are always welcome!

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