Which ISO setting do you use for UW?

[BurBunny]

There are definitely times when a higher ISO underwater is necessary. Recently several friends went to Cocos and for their hammerhead shots they were taking the ISO up quite a ways. Yes, that is obviously without a strobe, but that type of shot and shooting condition isn't at all unusual.

 

[f3nikon]

Double post

 

[f3nikon]

There are definitely times when a higher ISO underwater is necessary. Recently several friends went to Cocos and for their hammerhead shots they were taking the ISO up quite a ways. Yes, that is obviously without a strobe, but that type of shot and shooting condition isn't at all unusual.

It may have helped your friends out if they seen Howard Hall's hammerhead shots with a strobe and shooting in an upward direction. Shooting upwards will give you more than enough light to properly expose an image at the lowest ISO, even without a strobe. Shooting upwards is another rule of U/W photography, keep that ISO setting low for the finest image possible.

Then one can argue that the higher ISO can give you better DOF or one f stop (smaller aperture openings) for every one increase in ISO setting...big deal! For what is the gain in DOF when the light from the strobe cannot travel far enough to properly expose the "back" in-focus part of the subject without burning up the "front" part of the subject?

http://www.howardhall.com/

 

[alcina]

Perhaps there is more than one way to skin a cat...

 

[HowardE]

ISO doesn't change the DOF either.

A properly exposed shot with a higher ISO will have less noise than a 'pushed' low ISO shot. Pushing exposure too much in post processing will pull grain out in the image as well. Areas overexposed or underexposed too much will not carry any detail information for post processing to work with...

Another words, if you can't properly expose a shot(or get close) at low ISO and any useable shutterspeed and aperture; you'll want to raise the ISO to retain detail - even if it costs a bit of noise.

ISO doesn't change DOF, but it allows you to set higher F stops.

Like Alcina says - there's no steadfast rule here. It's interesting to see what other people do.

Again - I think the cameras ability to use higer ISOs with little additional noise is also a factor. Canons have a reputation of being really good at higher ISOs than others (as I've been told by camera store owners) -

I did some test shots where I set the camera up (topside) and focused on a color image (a calendar on my wall) and shot in 100, 200, 400, and 800.

I could definitely notice a difference between all 4.

At 100 - there was no noise at all in the image.
200- noticible noise in some of the colors, but not all
400- noticible noise all around (but not too severe)
800 - noise.

So - really experimentation is probably your best friend in this situation.

 

[desiredbard]

Sure the last one was not shot at 800........
I will also try tomorrow, but ..... does it matter if you flash externally or not?

BTw out of the 26mm era.... 100 is slower than 400 due to smaller grains was it not
Or was it the other way around I used to do some B&W photofraphy which you do at a 100..

 

[HowardE]

Sure the last one was not shot at 800........
I will also try tomorrow, but ..... does it matter if you flash externally or not?

BTw out of the 26mm era.... 100 is slower than 400 due to smaller grains was it not
Or was it the other way around I used to do some B&W photofraphy which you do at a 100..

The ASA setting you would use on film cameras depends on the film. The FILM is what has the rating. For the internal light meter of your camera to get proper exposure, you have to set the ASA on the camera to match the film speed.

 

[MasterGoa]

OMG!!!

D-Rings on every ear!!!!

I had never though of that

Good hook up point for a backup light...:lol2:

 

[HowardE]

OMG!!!

D-Rings on every ear!!!!

I had never though of that

Good hook up point for a backup light...:lol2:

I think she wants to clip her octo off on one of those :rofl2:

 

[MasterGoa]

Hey, just noticed you are from Breckeinridge!

Could you recommend good place to dive in CO?

MG