film speed

[BrianM]

For shallow underwater photography, is there any advantage in using a
high speed film? By shallow I mean a max depth of 5 metres.
I would be using a flash anyway, for distances from 2 metres to macro.
For land photos with same camera I use Kodak 200ASA. Would this be
adequate underwater?. Camera has 32mm lens f/3.5
I want to mainly film closeups of corals and reef fish rather than
seascapes/silhouettes.
What would be an example of needing a high speed film.

cheers and safe diving

Brian

[DavidM]

Post by BrianM
For shallow underwater photography, is there any advantage in using a
high speed film? By shallow I mean a max depth of 5 metres.
I would be using a flash anyway, for distances from 2 metres to macro.
For land photos with same camera I use Kodak 200ASA. Would this be
adequate underwater?. Camera has 32mm lens f/3.5
I want to mainly film closeups of corals and reef fish rather than
seascapes/silhouettes.
What would be an example of needing a high speed film.

I use a housed Nikon SLR so it's not really *exactly* the same (yours is a
point and shoot?) but for general "reefscape" with a 20mm Nikkor lens and
dome port and without using the strobes, start at f8 (and bracket up or down
as per the internal lightmeter), 1/60th sec shutter speed, and I get a good
result on either 64 or 100 ASA Fuji slide film. Sensia is fine, and to my
eye gived the same results as Provia. I've always forund Kodak films are
slightly too green in cast, even when exposed correctly, and there's not
really enough light to go higher than 100ASA. Going higher you can lose
colour and get very grainy (esp print film) but maybe this might be what you
want for a certain shot? High speed black and white films can give a good
"grainy" result which I think can be very evocative for wrecks and other
"unnatural" subject matter... For macro I'd definitely keep the film as slow
as possible and stay to slide film rather than negative film. Even try
taking 100ASA at 64ASA (or lower) and pull-processing it...but I haven't
really done a lot of macro.

HTH
David M

[BrianM]

Post by DavidM

Post by BrianM
For shallow underwater photography, is there any advantage in using a
high speed film? By shallow I mean a max depth of 5 metres. I would be
using a flash anyway, for distances from 2 metres to macro. For land
photos with same camera I use Kodak 200ASA. Would this be adequate
underwater?. Camera has 32mm lens f/3.5 I want to mainly film closeups
of corals and reef fish rather than seascapes/silhouettes. What would
be an example of needing a high speed film.

I use a housed Nikon SLR so it's not really *exactly* the same (yours is
a point and shoot?) but for general "reefscape" with a 20mm Nikkor lens
and dome port and without using the strobes, start at f8 (and bracket up
or down as per the internal lightmeter), 1/60th sec shutter speed, and I
get a good result on either 64 or 100 ASA Fuji slide film. Sensia is
fine, and to my eye gived the same results as Provia. I've always
forund Kodak films are slightly too green in cast, even when exposed
correctly, and there's not really enough light to go higher than 100ASA.
Going higher you can lose colour and get very grainy (esp print film)
but maybe this might be what you want for a certain shot? High speed
black and white films can give a good "grainy" result which I think can
be very evocative for wrecks and other "unnatural" subject matter... For
macro I'd definitely keep the film as slow as possible and stay to slide
film rather than negative film. Even try taking 100ASA at 64ASA (or
lower) and pull-processing it...but I haven't really done a lot of
macro.
HTH
David M

thanks David.
Yes the camera is a simple compact auto point and shoot with fixed focus
underwater, so there's not a lot I can do about exposure but you've reminded
me of the benefit of using slide film. IIRC I've used Agfa 25ASA with very good
results. As a flash will be used for virtually every shot, I think I'll
follow your advice and stay at or below 100ASA. For black and white, I think a
medium format camera would be OK, but the housing would need to
be as big as a divers hard hat.
Also have a digital camera which I get a lot of use out of above the tide
mark. There are a few recent pics of Rarotonga on my hobby website
http://linuxguide.co.nz Next trip there I hope to get some Moorish Idols
in the 35mm viewfinder

cheers
Brian