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Home: Inactive Forums: Underwater Video:
Newbie Question- Focus - manual or auto?

 
 


RickSp
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Feb 18, 2005, 7:17 AM

Post #1 of 5 (2056 views)
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Newbie Question- Focus - manual or auto? Can't Post
Last night I tried out my PD150 in an Ikelite housing in a swimming pool prior to a trip to Bonaire in March. Overall, I am pleased. I am also aware that I need to learn a whole new style of shooting. I have read with interest the comments about manual white balancing underwater. I'll have to give that a try.

What is the concensus on staying in focus. Should I manually focus relatively close and then rely on small CCDs and the wide angle lens to give me sufficeint depth of field for most purposes or should I just say the Hell with it and put the camera in autofocus? I do not think that I can rely on my eyes to accurately focus the camera but I would like to avoid the "pumping " effect of autofocus which can really screw up tough shots.

Any and all wisdom greatly appreciated.

Rick Spilman
Meridian Multimedia
www.meridianmultimedia.com


bubblevision
Novice


Feb 19, 2005, 8:13 PM

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Re: [RickSp] Newbie Question- Focus - manual or auto? [In reply to] Can't Post
Hi Rick,

I shoot with a VX2000 in a Gates housing with the standard port. I almost always shoot in auto-focus and the resulting picture is nice and sharp. If we have bad visibility it sometimes pumps, but this is pretty rare here in Thailand/Burma. I guess you'll have good vis in Bonaire although I haven't been myself.

If I'm shooting close-up with still or slow-moving subjects I sometimes manually focus if I can see the camera is obviously focussing on the wrong thing. For example the other night I wanted to video a sleeping parrotfish but the camera was auto-focussing on it's mucous cocoon, so I manually focussed on its eye instead.

A colleague of mine was shooting with a VX2000 in an Ikelite housing and I seem to remember he was getting more pumping/hunting that I was with the Gates, so bear that in mind.

Let us know your experiences and which way you end up doing it.

Nick
_________________________________________
Bubble Vision underwater video & marine life DVD, Phuket, Thailand
Sony VX2000, Gates housing, L&M Sunray lights
Sony Vegas


sjspeck
Novice


Feb 21, 2005, 10:55 AM

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Re: [RickSp] Newbie Question- Focus - manual or auto? [In reply to] Can't Post
Leave the A/F on for most filming, mine works fine while gliding over the reef etc. I sometimes manually focus on small objects when shooting closeups.

Speaking of Bonaire, that's one time the A/F was fooled. We filmed last summer at Salt Pier. As I'd pan off the pier supports, it would pick up the sun reflecting at the surface, change focus, and then pick up the blue in the water and change focus again until I panned back across a pier structure which would pop back into focus. If you've never dove it, I recommend it. It's shallow, the light is good and there's lots of coral and macro stuff clinging to the pilings shallower than 40'. We filmed some 12-15" Angelfish there who live at the base of one of the structures doing their normal routine. Dive it in the morning and you'll get the same results as the photo in this months ScubaDiving, the sun streams through the pilings if you catch it just right. One of the structures was only in about 25fsw so there's a lot of filming time.

Steve


(This post was edited by sjspeck on Feb 21, 2005, 10:57 AM)


realfish
Novice

Feb 21, 2005, 3:16 PM

Post #4 of 5 (1963 views)
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Re: [sjspeck] Newbie Question- Focus - manual or auto? [In reply to] Can't Post
I like manual on all the time. With a flat port and a wide angle lens(or not)on the camera, focus in auto in air about 20' away in telephoto and zoom in. Wait until the camera finds sharp focus, hit manual, locking the focus. Then go back to wide angle...everything from close to far is now in focus u/w.
With a wide angle lens/dome on the housing however, go to auto while in full wide, select an item(in air)about 30" away. Let it find focus, then hit manual.Everything should be in focus u/w.You may need to play with the set-up focus distance on this one(24"-36"?), however.
PRACTICE, PRACTICE! Art Nelson
an


RickSp
User

Feb 22, 2005, 8:08 AM

Post #5 of 5 (1934 views)
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Re: [realfish] Newbie Question- Focus - manual or auto? [In reply to] Can't Post
Thanks for the replies. Very interesting. I am leaning toward setting the focus in manual and leaving it alone. This is one time when small CCDs are an advantage. Depending on the light with a wide angle lens, and 1/3" CCDs the depth of field is close to infinite. I will have to play around to see what works best.

Rick Spilman
Meridian Multimedia
www.meridianmultimedia.com