Look Ma, No Flash

Dan Bracuk wrote:
> Dan Bracuk <bracuk@pathcom.com> pounded away at his keyboard resulting
> in:
> :WRT lightening images, Microsoft Digital Image Pro, which I use has a
> :Add Flash feature. It works really well with underwater shots in that
> :not only does it add light, it also brings out the colours. I'll show
> :you guys a before and after example in a little while.
>
> Here is a photo enhanced 3 times. Two of the enhancements were done
> using techniques mentioned in this thread.
>
> http://www.pathcom.com/~u1072675/x/
>
> Dan Bracuk
> If we don't succeed, we run the risk of failure.
>
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There is a pretty reasonable improvement with the levels fix. You might
want to have a go at some more complex colour correction. If you have
photoshop then there are loads of resources on the subject. If not you
can download GIMP free of charge and most of the techniques can be used
but you might have to figure out what the photoshop term for a function
is in GIMP. Here is a link to a fairly comprehensive colour correction
resource http://www.scubaboard.com/cms/article18-doc5.html. The
Mandrake method is one that I have found particularly useful in the
past. I had a go using it on a couple of your shots and in my eyes it
gives them another boost to what I imagine the scene looked like when
you pushed the shutter.

jon

Dan Bracuk wrote:
> "Dave C" <dcalderbank@top.monad.net> pounded away at his keyboard
> resulting in:
> :Otherwise, how about setting your shutter fast enough to freeze motion
> :and correcting underexposure later? That's just a thought, as I haven't
> :done much lightening of images and don't know how much would be lost.
>
> That's what I had in mind all the time. Has anyone done this before?
> What shutter speed did you use? Did you also keep a constant f-stop
> or did you keep that on automatic? How were the results.

The minimum shutter speed required to adequately reduce blur will vary,
of course, but I would try 1/60 or faster.

You apparently were talking about 70' in tropical water, so perhaps you
were only missing by a stop or two.

Any idea what your camera chose for shutter and aperture for those
blurry shots you talked about?

You might as well use shutter priority and let the camera choose
aperture automatically. This will mean that the dimly lit moving
subjects will be less blurred, but may be underexposed to varying
degree.

Try a few shots at home in dim light and then try to correct the
underexposure after the fact. Your dog's wagging tail might be a good
test subject. 8^)

If we're only talking about a couple of stops of underexposure, maybe
the correction will look okay to you.

If I were to use shutter priority set at 1/60th in my local waters, as
I get below 40', the diminished ambient light would give me at least a
4-stop degree of underexposure. I think that's a lot to correct, but I
might check that out next time I dive. Can't be much worse than getting
a blurry image!

Dave C

Dan Bracuk wrote:
> "Dave C" <dcalderbank@top.monad.net> pounded away at his keyboard
> resulting in:
> :Otherwise, how about setting your shutter fast enough to freeze motion
> :and correcting underexposure later? That's just a thought, as I haven't
> :done much lightening of images and don't know how much would be lost.
>
> That's what I had in mind all the time. Has anyone done this before?
> What shutter speed did you use? Did you also keep a constant f-stop
> or did you keep that on automatic? How were the results.

The minimum shutter speed required to adequately reduce blur will vary,
of course, but I would try 1/60 or faster.

You apparently were talking about 70' in tropical water, so perhaps you
were only missing by a stop or two.

Any idea what your camera chose for shutter and aperture for those
blurry shots you talked about?

You might as well use shutter priority and let the camera choose
aperture automatically. This will mean that the dimly lit moving
subjects will be less blurred, but may be underexposed to varying
degree.

Try a few shots at home in dim light and then try to correct the
underexposure after the fact. Your dog's wagging tail might be a good
test subject. 8^)

If we're only talking about a couple of stops of underexposure, maybe
the correction will look okay to you.

If I were to use shutter priority set at 1/60th in my local waters, as
I get below 40', the diminished ambient light would give me at least a
4-stop degree of underexposure. I think that's a lot to correct, but I
might check that out next time I dive. Can't be much worse than getting
a blurry image!

Dave C

Dan Bracuk wrote:
> "Dave C" <dcalderbank@top.monad.net> pounded away at his keyboard
> resulting in:
> :Otherwise, how about setting your shutter fast enough to freeze motion
> :and correcting underexposure later? That's just a thought, as I haven't
> :done much lightening of images and don't know how much would be lost.
>
> That's what I had in mind all the time. Has anyone done this before?
> What shutter speed did you use? Did you also keep a constant f-stop
> or did you keep that on automatic? How were the results.

The minimum shutter speed required to adequately reduce blur will vary,
of course, but I would try 1/60 or faster.

You apparently were talking about 70' in tropical water, so perhaps you
were only missing by a stop or two.

Any idea what your camera chose for shutter and aperture for those
blurry shots you talked about?

You might as well use shutter priority and let the camera choose
aperture automatically. This will mean that the dimly lit moving
subjects will be less blurred, but may be underexposed to varying
degree.

Try a few shots at home in dim light and then try to correct the
underexposure after the fact. Your dog's wagging tail might be a good
test subject. 8^)

If we're only talking about a couple of stops of underexposure, maybe
the correction will look okay to you.

If I were to use shutter priority set at 1/60th in my local waters, as
I get below 40', the diminished ambient light would give me at least a
4-stop degree of underexposure. I think that's a lot to correct, but I
might check that out next time I dive. Can't be much worse than getting
a blurry image!

Dave C

"Zen Diver" <spicedhamme@yahoo.com> wrote in message
news:S9udnXZEMKsVERnYnZ2dnUVZ8tOmnZ2d@pipex.net...
>
> I had a go using it on a couple of your shots and in my eyes it gives them
> another boost to what I imagine the scene looked like when you pushed the
> shutter.

Can you send a link so we can see them? Thanks for the link to the
photoshop information.

"Zen Diver" <spicedhamme@yahoo.com> wrote in message
news:S9udnXZEMKsVERnYnZ2dnUVZ8tOmnZ2d@pipex.net...
>
> I had a go using it on a couple of your shots and in my eyes it gives them
> another boost to what I imagine the scene looked like when you pushed the
> shutter.

Can you send a link so we can see them? Thanks for the link to the
photoshop information.

"Zen Diver" <spicedhamme@yahoo.com> wrote in message
news:S9udnXZEMKsVERnYnZ2dnUVZ8tOmnZ2d@pipex.net...
>
> I had a go using it on a couple of your shots and in my eyes it gives them
> another boost to what I imagine the scene looked like when you pushed the
> shutter.

Can you send a link so we can see them? Thanks for the link to the
photoshop information.

"Dave C" <dcalderbank@top.monad.net> pounded away at his keyboard
resulting in:
:
:The minimum shutter speed required to adequately reduce blur will vary,
:of course, but I would try 1/60 or faster.
:
:You apparently were talking about 70' in tropical water, so perhaps you
:were only missing by a stop or two.
:
:Any idea what your camera chose for shutter and aperture for those
:blurry shots you talked about?
:
:You might as well use shutter priority and let the camera choose
:aperture automatically. This will mean that the dimly lit moving
:subjects will be less blurred, but may be underexposed to varying
:degree.
:
:Try a few shots at home in dim light and then try to correct the
:underexposure after the fact. Your dog's wagging tail might be a good
:test subject. 8^)

I just tried a couple of shots in a room with the lights on. With no
flash, I could not get enough light. It was almost a completely dark
picture.

All is not lost though. While I prefer to not have to, I can always
switch back and forth in the water. My filter is a slide-on so
putting it on and off is easy. Plus it's on a lanyard so I might not
lose it.

The tough part will be knowing whether or not the flash is on or off.
It's a small display and I'm old and blind. I guess I'll have to
photograph my hand or something and see if the flash goes off. Nice
to not have to worry about wasting film.

In any event, thank you for your thoughts.

Dan Bracuk
If we don't succeed, we run the risk of failure.

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"Dave C" <dcalderbank@top.monad.net> pounded away at his keyboard
resulting in:
:
:The minimum shutter speed required to adequately reduce blur will vary,
:of course, but I would try 1/60 or faster.
:
:You apparently were talking about 70' in tropical water, so perhaps you
:were only missing by a stop or two.
:
:Any idea what your camera chose for shutter and aperture for those
:blurry shots you talked about?
:
:You might as well use shutter priority and let the camera choose
:aperture automatically. This will mean that the dimly lit moving
:subjects will be less blurred, but may be underexposed to varying
:degree.
:
:Try a few shots at home in dim light and then try to correct the
:underexposure after the fact. Your dog's wagging tail might be a good
:test subject. 8^)

I just tried a couple of shots in a room with the lights on. With no
flash, I could not get enough light. It was almost a completely dark
picture.

All is not lost though. While I prefer to not have to, I can always
switch back and forth in the water. My filter is a slide-on so
putting it on and off is easy. Plus it's on a lanyard so I might not
lose it.

The tough part will be knowing whether or not the flash is on or off.
It's a small display and I'm old and blind. I guess I'll have to
photograph my hand or something and see if the flash goes off. Nice
to not have to worry about wasting film.

In any event, thank you for your thoughts.

Dan Bracuk
If we don't succeed, we run the risk of failure.

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

"Dave C" <dcalderbank@top.monad.net> pounded away at his keyboard
resulting in:
:
:The minimum shutter speed required to adequately reduce blur will vary,
:of course, but I would try 1/60 or faster.
:
:You apparently were talking about 70' in tropical water, so perhaps you
:were only missing by a stop or two.
:
:Any idea what your camera chose for shutter and aperture for those
:blurry shots you talked about?
:
:You might as well use shutter priority and let the camera choose
:aperture automatically. This will mean that the dimly lit moving
:subjects will be less blurred, but may be underexposed to varying
:degree.
:
:Try a few shots at home in dim light and then try to correct the
:underexposure after the fact. Your dog's wagging tail might be a good
:test subject. 8^)

I just tried a couple of shots in a room with the lights on. With no
flash, I could not get enough light. It was almost a completely dark
picture.

All is not lost though. While I prefer to not have to, I can always
switch back and forth in the water. My filter is a slide-on so
putting it on and off is easy. Plus it's on a lanyard so I might not
lose it.

The tough part will be knowing whether or not the flash is on or off.
It's a small display and I'm old and blind. I guess I'll have to
photograph my hand or something and see if the flash goes off. Nice
to not have to worry about wasting film.

In any event, thank you for your thoughts.

Dan Bracuk
If we don't succeed, we run the risk of failure.

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----= East and West-Coast Server Farms - Total Privacy via Encryption =----