Hi EOSophiles,

I am trying to get hold of an �eyepiece� to put on my telephoto lenses, in 
place of the camera body so that I can use them as telescopes, in order to 
save weight (not to mention money) when out photographing & watching 
wildlife.

My first question is - does anyone know where I can come by such a device in 
a Canon EF fit? WJM has told me that he has seen such items advertised in 
the past but not recently.

I have obtained a �Minolta Lens/Monocular Converter� & found a company 
called SRB Film in Luton, England who are very helpfully prepared to convert 
the mount on it to Canon EF but I would also like to be able to take 
advantage of the image stabiliser on my 100-400. I found the lens contact 
pin-out details (below) on WJM�s site but I am not an electronics expert. 
Can anyone tell me what is likely to be needed to turn on the IS?

Martin Wiseman wrote the following on 10/8/98:

---------------------------------------------------------------------------------
�Looking at the front of the camera body and reading from left to right, the 
signals are:

1. VBAT
2. P-GND
3. P-GND
4. VDD
5. DCL
6. DLC
7. LCLK
8. D_GND

Pins 2 and 3 are combined into one large contact on the lens. My 
interpretation of these signal names is as follows:

VBAT    - Battery power for driving motors etc.
P_GND   - Power ground - the return path from motors to battery negative.
VDD     - Power for the logic circuitry
D_GND   - Digital ground for the logic circuits
DCL     - Data from Camera to Lens
DLC     - Data from Lens to Camera
LCLK    - Data clock

Other people have suggested that the data protocol is probably 8 bit serial 
at 62.5 kHz and possibly based on the Motorola SPI interface.�
-------------------------------------------------------------------------------------------

I have not tried simply putting 6 volts across pins 1 & 2 yet but I imagine 
that there will be something more complicated than that needed to activate 
the IS.

I have mailed MW who says that this may work however, especially if I add 
the correct data voltage across pins 4 & 8: Since early bodies were not 
aware of IS there can be no signal specifically sent to activate the IS but 
there may be a general �wake-up call� sent to the lens. Does anyone know 
what data voltage is used, to save me much effort with my multimeter & 
trying to fool my EOS 3 into believing the lens is on when it isn�t?

WJM has suggested using the Novoflex Lens Reversal Adapter (that maintains 
electrical contacts to the lens when it is detached from the camera body) & 
using the camera body itself to activate the IS. This would certainly do the 
trick, however it would be a bit cumbersome for bird watching to have the 
camera body suspended nearby all the time, & the eyepiece would have to be 
used with the Novoflex adapter even on non-IS lenses because it would have 
to be suitably shortened. I would far prefer to find out what signals need 
to be sent to the lens to switch the IS on, & try to incorporate a battery & 
a device to give these signals into the eyepiece, or mounted on it.

Anyway, this is all I have managed to find out so far & I would greatly 
appreciate it if someone can enlighten me further before I risk blowing up 
my treasured IS lenses! Can anybody help please?


_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp

*
****
*******
***********************************************************
*  For list instructions, including unsubscribe, see:
*    http://www.a1.nl/phomepag/markerink/eos_list.htm
***********************************************************

Reply via email to