Charlie,
I tried finding information on "Hoya doublet +10 diopter " in both
google.com and in Lap.com search engins, with zero results. where would I
look to read up on what it is? I went to the 2 links you so kindly provided
and find it a bit over my head ( I do have a BS in Physics and Math 1963
grad) I would love to fully understand, and don't mind additional reading to
fill me in so I can make full use of your valuable input :)


"Charlie" <cdilks@bellatlantic.net> wrote in message
news:cdilks-0EA184.07540529062003@news.fu-berlin.de...
> I like to use diopters with my 5050.
> The super macro specifies a focal length of 59mm (equiv to 35mm), has a
> very short lens to subject distance of 1 inch and has barrel distortion.
> I have a Hoya doublet +10 diopter which gives around 1.4 times the
> magnification of the "super macro" at a lens to subject distance of
> 2 3/8 inches with no distortion. Being a doublet, it has excellent
> quality.
>
> Here's a comparison picture.
> http://tinyurl.com/7voc
>
> Here's a picture showing the super macro compared to +4 and +2 single
> element diopters. That combination equals the magnification of the SM
> with a lens to subject distance of 3.2"
> http://tinyurl.com/6qjb
>
> -- 
> Charlie Dilks
> Newark, DE  USA