Ah, forensics is QUITE a different matter! ;-)

I reasonably assumed from your post that you taught

"ordinary" photography...;-) For most, the common

impression that many commonly-used weak-colored

filters will aid image-making enough to buy and

bother to use them is false - but obviously for

your purposes (and the purposes of many other

photography-users), the effects of the

strong-colored filters can be useful. For most

others, though, the effects are generally confined

to adjusting the relative brightness of the sky

tones, since clear sky-blue is the only common

important highly-saturated color (that one might

wish to modify) likely to be in photographs...

 

On Thu, 30 Jan 2003 21:46:59 GMT, "McLeod" <wmcleoa910@rogers.com> wrote:

 

>Actually, shooting the fire hydrant against the lawn is an exercise we use

>to explain the use of filters, colour wavelengths, processing film, and

>printing.  All of which lead into how the use of panchromatic black and

>white film can record certain forensic evidence better than colour film.

>What sort of "real-world" shooting are you referring to?

 

>> This was my point: for most average subjects, under

>> most conditions, the differences with most filters

>> will be minor; with high-saturation colors (mainly

>> the sky in nature, though flowers, hydrants, etc.

>> are also notable) the differences *are* noticeable,

>> but why would you want to modify the tonality of

>> a hydrant, car, flower, etc. (with the exception of

>> the sky...)? Otherwise, you are just doing meaningless

>> exercises, like using inappropriate color-correction

>> filters with slide film...;-) Sure, I can shoot a color

>> chart with B&W film using various filters and "prove"

>> their effects - but in MOST "real-world" shooting, it

>> is useful to know that the effects of most filters are

>> too subtle to worry about (or spend the money on, or

>> lose the effective sensitivity for, etc.). This is a

>> more useful lesson for students than finding the

>> few exceptions, I think...;-)

>>   David Ruether