BUG RIDERS LOVE THE 20D !!!

"Annika1980" writes:
Here's one taken with the 65mm MP-E Macro by itself
without and extension tubes or teleconverter:
http://www.pbase.com/bret/image/42936051

Must be nice and convenient and it's a high quality shot. The MP-E is
a little too rich for my blood but it makes me want to get one of
those 640x480 USB microscopes.

And here's a full-frame shot (reduced about 25%)
of the back of a US $20 dollar bill.
http://www.pbase.com/bret/image/42936052

Oh cool! I'd have never recognized it.

In message ,
wrote:

In message ,
Paul Furman wrote:

I guess that lens
ain't too bad if it does so well at 5x magnification wide open.

It wasn't wide open. The camera was set to 5.6, but it acknowledges the
2x, but not the 1.4x, so the real f-stop was 8 (and the real focal
length 252mm.

Sorry, I had that backwards. The camera saw the 1.4x, and not the 2x.
The lowest f-stop as far as the camera was concerned was f4, and I had
it a stop down at 5.6.
--


John P Sheehy

wrote:

In message ,
Paul Furman wrote:


JPS's is really nice but has some of that over-active
highlight stuff that I was seeing wide open (sparkles on black ink),


Well, that was a first attempt, and I didn't really optimize a few
things. I used direct flash (believe it or not, the lens was about 4
inches from the subject), and it was too dark in the viewfinder (no
modelling light) to perfect focus. I didn't try the two TCs stacked
right on top of each other; they were separated by the extension tubes.

You must say, this 90mm Tamron goes *way* beyond the call of duty.
Without the TCs, the original pixels would be at least this good with a
64MP, 1.6x crop sensor, or the center of a 164MP full-(35mm)frame
sensor!

This may be one of the sharpest lenses available for the EOS mount.


LOL 164MP?!?!?, I don't know, I'm not the expert. It's all good to me!!
Thanks for the tests.


--
Paul Furman
http://www.edgehill.net/1
san francisco native plants

In message ,
Paul Furman wrote:

wrote:

You must say, this 90mm Tamron goes *way* beyond the call of duty.
Without the TCs, the original pixels would be at least this good with a
64MP, 1.6x crop sensor, or the center of a 164MP full-(35mm)frame
sensor!

This may be one of the sharpest lenses available for the EOS mount.


LOL 164MP?!?!?, I don't know, I'm not the expert. It's all good to me!!
Thanks for the tests.

It has to be. The TCs don't make the main lens any sharper; they just
use what the main lens can resolve more efficiently given a fixed pixel
pitch. It is logical that if there was a sensor of the same size that
had 2.8x as many pixels per linear mm as my 8.2MP camera, that the lens
would be able to resolve the same way it did with the TCs, without them,
or better (air instead of TCs).

8.2MP * 2.8 * 2.8 = 64.288MP

For full-frame, that would be

64.288MP * 1.6 * 1.6 = 164.577MP.

Of course, such sensors would only be quiet up to about ISO 200, and
would have limited use.
--


John P Sheehy

Try using it to take a shot of a sharp Velvia slide and compare that to
what
your Minolta 5400 produces.

(At 5x, that's 2400 x 5 dpi or so, which is a lot more magnification
than
the 5400 provides. Of course, you don't get the whole frame without a
_lot_
of workg.)
----------------------------------

I tried it an got pretty good results. As you mentioned, the
magnification
increase is huge, at least 4x what I get from the 5400. Of course that

doesn't mean you're getting 4x the amount of detail, but there does
seem
to be a slight increase.

David J. Littleboy wrote:

Try using it to take a shot of a sharp Velvia slide and compare that to what
your Minolta 5400 produces.

(At 5x, that's 2400 x 5 dpi or so, which is a lot more magnification than
the 5400 provides. Of course, you don't get the whole frame without a _lot_
of workg.)


Lots of stitching eh?

I've been playing with slide duplicating at about 1:1 with 6MP to get
the whole slide & it's not too bad.

--
Paul Furman
http://www.edgehill.net/1
san francisco native plants