Re: filmscanners: Pixels per inch vs DPI

[SKID Photography <skid@bway.net>]

Arthur Entlich wrote:

> SKID Photography wrote:
>
>  > Try taking 3 different photos (Poaloids will do), at a 60th, 125th
> and 250th of a second.  Will will see that
>  > there will be a significant exposrue difference between them.
>  >
>  > As far as 'spec' go, this would not b the first time that
> manufacturers fudged them.
>  >
>  >
>  > Harvey Ferdscneider
>  > partner, SKID Photography, NYC
>  >
>
> Are the faster shutter speed images in each case darker from the slower
> in your experience?

Yes

> If the factor is the flash, as you suggest, wouldn't that mean the
> duration is more in the order of 1/60th to 1/125th of a second or so, or
> that the output is otherwise being affected by the shutter speed
> timing/synching or whathaveyou?

Yes, this is what I have been saying.

> This seems like a very great
> discrepancy from the specs.  Since I do very little studio flash
> photography, preferring to work with static lighting for studio work,
> I've never tested my flashes under conditions which were well enough
> controlled to know for sure what is going on.

It is possible, with a dedicated camera/flash ttl auto thyristor system, that 
the flash unit will compensate
for the faster shutter speeds with more power output.

With a studio flash you can just use a flash meter and measure the difference 
in light capture at different
shutter speeds.

Harvey Ferdschneider
partner, SKID Photography, NYC