I've actually tested this out. DOF is a function of the absolute
magnification of the image on the sensor. So a 3-4mm long subject fills
the frame on a Q at 1:1. You'd need 5.6x lifesized to get that on a full
frame sensor. I do work at 5-10 lifesized with snowflakes and the DOF is
much shallower than at 1:1. So taking a very small subject with a Q or
other small sensor camera can make a lot of sense under some
circumstances. In the field a Q with 100mm macro at 1:1 magnification
would be much easier to work with than any lens on a FF camera set up to
get a 5.6:1 image (which would be pretty impractical.) But a 5.6:1 setup
is pretty easy to do in studio or semi-studio settings.
I tried using the Q for snow crystals but had problems with flare on the
reverse mounted lens. I need to try again with a better optic.
Mark
On 9/2/2014 4:05 PM, P.J. Alling wrote:
I'm not sure that you would get greater DOF. DOF is pretty much
defined by the diameter of the aperture, the distance to the target,
and reproduction size. I think I'd actually have to work out the math
of a 100mm f2.8 vs an 560mm (assume f5.6) for a particular distance
and reproduction size to know for sure. I don't think I want to do
that, because I'm basically lazy.
On 9/2/2014 1:48 PM, Boris Liberman wrote:
The additional property here would be the bigger dof that may prove
useful for this kind of photography...
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On September 2, 2014 8:36:21 PM Eric Weir <eew...@bellsouth.net> wrote:
Thanks, P.J.
On Sep 2, 2014, at 1:02 PM, P.J. Alling <webstertwenty...@gmail.com>
wrote:
> The Q is 12mp camera with a 5.6 crop factor. 100 x 5.6 so you'd
have the AOV of a 560mm lens on 35mm using that lens with the Q.
Which is super telephoto by any definition. You could also get the
same effect by using that lens on a ff sensor with 72mp and cropping
to 12mp from the center of the frame. (I know of no manufacture
making a 72mp ff sensor so don't ask, I just multiplied in my head
which is less sure than it used to be so if I'm wrong tough).
>
> On 9/2/2014 6:18 AM, Eric Weir wrote:
>> On Sep 2, 2014, at 12:27 AM, Boris Liberman <bori...@gmail.com>
wrote:
>>
>>> I would probably leave Sigma 135-400 behind... Instead, you
could bring Q, K to Q adapter, and get by DFA 100 macro for extreme
telephoto…
>> I don’t understand this. How would a 100mm macro on a Q be
provide extreme telephoto capability? (Not doubting, just would like
to know.)
>>
>>
------------------------------------------------------------------------------------------
>> Eric Weir
>> Decatur, GA USA
>> eew...@bellsouth.net
>>
>> "You keep on learning and learning, and pretty soon
>> you learn something no one has learned before."
>>
>> - Richard Feynman
>>
>>
>
>
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> -- Woody Allen
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eew...@bellsouth.net
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