Thanks Anthony.
I took a few before reading this but i think i'm ok.
I used the 10mm tube for some red sunflower and yellow/purple iris's.I used
a handheld meter to which i added 1 stop.
After i put the tubes back into their box,i noticed a piece of onion skin paper folded
up
and
stuffed tightly to the top of the box. I unfolded it and lo and behold,instructions.
lol
I looked at what combo i had and was pretty close.As this is C41 and B&W film used, i
think i;ll
be ok.
Thanks all for the help.
Back to flower hunting.I borrowed works Manfrotto 028 tripod.Makes a BIG difference.<g>
Dave
> Dave,
>
> Firstly, if you're metering TTL, and/or using OTF flash automation with the
> Super Program you won't need to compensate for anything, the internal meter
> will be affected by the extensions exactly the same as the film will be.
>
> If you're transferring exposure values from an external meter, or using a
> non-TTL/OTF auto flash, then you will need exposure compensation. I'll
> write the formula longhand because I'm sure that the autowrap of one of our
> email clients would mangle any multiline formula I try to write. It is:
>
> The corrected aperture (the one you actually set the lens to) is equal to
> the indicated aperture (what the external meter indicates) times the lens's
> focal length divided by the extended focal length (FL plus extension).
>
> Don't forget to include the extension of the focusing helical, either.
>
> A rough guide could be that a tube of 1/4 the objective's focal length adds
> about 1/2 stop. A tube of half the objective's focal length adds about a
> stop. A tube equal to the focal length adds 2 stops. These are when the
> lens itself is at infinity focus, any helical extension adds a little more.
> However, non-macro lenses rarely extend more than about 1/3 stop's worth on
> their own helical.
>
> Happy (flower) hunting.
>
> regards,
> Anthony Farr
>
> ----- Original Message -----
> From: <[EMAIL PROTECTED]>
>
> >
> > Hi all.
> > First off,got an email from Aaron.Hes on holidays for the next two weeks.
> That will buy me
> > some time
> > to take some more photos.lol
> >
> > Second,i ts a lovely day today,i have it off and plan to shoot some
> closeup flowers.I want
> > to use the SP
> > with the K adaptor and screw in some M42 tubes.I realize some exposure
> factors will be
> > needed.Is
> > there a rule of thumb.Probably only the first and or second tube.Is 0ne
> stop per tube a
> > good starting
> > place??
> >
> > I'll check back this afternoon.
> >
> > Dave
> >
> >
> >
>
