Manual exposure, manual focus

I'm interested to know how many of you are actually using manual exposure and manual focus during your dives.

As far as focus is concerned, personally I only ever use manual when I can see that my camera is focussing on the wrong thing. Which is usually when I'm shooting something small and the camera is picking up on the background. Otherwise it's a handful and anyway I don't trust my eyes to get it right, especially underwater. Many a time when I have tried it I've come out and found that my subject's not sharp.

As for exposure, yes, on night dives or in dark places (when I have time) I generally use manual to stop my subjects getting over-exposed against the black background. But during the day I've usually got my hands so full with white balancing, zooming, framing, holding the camera steady, following the VX2K's neutral density filter prompts, and just getting the damn shot that I run on auto nearly the whole time.

I just can't imagine handling manual exposure as well as all this, not to mention manual focus. I keep telling myself that I really ought to be doing everything on manual, but in reality it's just too much to do and I would just miss too many shots while I was faffing about.

Admittedly though, the controls on the Gates are not as convenient as controls on the handles of an electronic housing.

For those of you who are routinely using manual exposure, some questions...

- How are you judging it? Just eyeballing it or using zebra stripes? If so do you run with 70% or 100% for the zebra (those are my Sony's options)?

- Are you judging exposure (and focus) on a monitor or through the viewfinder?

- Do you adjust exposure during a take or just set it up before you record? What happens when your sweetlips swims out of the cave and into bright sunshine.

- How often are you changing exposure during a dive?

- Do you miss shots that you would otherwise have got if you were running on auto?

Nick

Hey Nick

I am a half and half sort of person on that stuff. On a nice clear viz dive i usually leave it on auto focus/auto exposure.

But i dive a lot in crap viz and then i am always in Infinity for WA and then back to auto focus for anything where i have to zoom ie: macro stuff.

On the exposure again i leave it on auto a lot but in wierd lighting conditions or when looking for a special effect i will go to manual. I find the auto exposure on the Z1 is pretty darn good to tell you the truth...

Night dive? whazzat?

Well auto focus with pelagics in plankton rich water is a challenge. Nothing like having that school of hammerheads going in and out of focus just as they turn broadside. I've set manually on infinity with some success in those conditions. A better trick is to autofocus and hold focus at that distance if your camera can do that, as 'infinity' can focus past the subject unless you have fantastic DoF (and fantastic viz). Truth is in those really wild moments when stuff is flying around I usually stick with auto and edit out the blurs in post prod.

I use the auto and hold technique for macro a lot. Some 'pros' tell me they do everything on manual focus, but it seems I'm too uncoordinated and too blind to do it much when the action starts...

Re exposure, I definitely used to go manual to avoid burn out on nights dives, and I know divers who swear by zebra control at all times. Unfortunately it looks like I can't access manual exposure (except for backlight - which is v useful to open up a stop on those darker subjects) with my new A1 set up.

Changing settings during a take is too much like changing wheels on a moving car; for me anyhow....

learning learning learning

The jury is stil out for me on manual vs auto focus. For good vis and conditions and wide angle, i find focusing:) my efforts on framing the shot, positioning the subject and capturing the motion is a better use of my time then managing the manual focus. When the image pops in and out, i just edit this footage out. I am delighted with with the quality of focus of my FX1. Whereas my 950 would lose focus frequently, the FX1 has been rock solid.

In low vis environments, I tend to use the 1 push manual focus. When i can lock on a subject of desired distance, I lock the focus. I find the process to be annoying however when the subject suddenly turns toward me and goes out of focus. Seems like i need to keep my thumb on the focus trigger at tall times in manual mode.

I am lazy with the exposure during day dives for the most part. When i shoot up into the light, i use the ND filters or iris sometimes. ON night dives, i always adjust exposure as the dark backgrounds always open the exposure too high. i step this down to avoid burn out of the subject. This is especially important for subjects such as squid or cuttle fish that are swimming in the open blue (black at night). i use the visual feedback in the monitor to determine the level. be careful however because the monitor tends to be brighter than real life so you run the risk of underexposing. trial and error will help get this right.

Overall I focus most of my energy on capturing stable footage with great composition and subject matter (that is the goal at least:)). Focus techniques and exposure are secondary. You can fix many of these things in post but it is really hard/impossible to fix the composition and remove obvious camera shake.

Gotta say i am shocked with two of you and problems with infinity. I have never had a problem with infinity and mantas. believe me, Miil channel can at times remind me of BC, freakin green!!! have never had a focus problem on infinity with either Z or 950..

Interesting

Mike, to clarify...no problem with infinity and focus. just when the manta swims comes in from 50 feet way and swims straight over you...i have not found that infinity cuts it...it is fuzzy on both ends of the shot....otherwise we would all shoot infinity all the time:) The focus issue is with auto in low vis.

Wow, much of this if very surprising to me. I have used Gates housings since the old TR101 hi 8 days. I love them as they are as dependable as you can ever hope for. I learned long ago never to use auto focus, especially when shooting wide angle. Manual focus keeps everything nice and tight for me. Very surprised to hear that so many of you do not shoot in manual. There is nothing worse in my book to have a great shot ruined because the auto forgets what it is focusing on. Actually, the only time I ever use auto focus is if I am in someplace like Lembeh Straits where shooting is really all super macro. Then, and really only then, is when I use auto focus. Well, each to their own I always say.

Hope you are all planning to submit a film or two to this years San Diego UnderSea Film Festival. Look forward to seeing your work.

Steve

Well I suppose I should put my 2 cents in.

Full wide on manual-infinity focus the subject will go soft/unsharp if the aperture is very low (to dark). The more light the higher the fstop is the closer the subject can be to the lens on infinity/ full wide and still be sharp. I hate camera hunting with auto focus on wide shots.

The subject will also go unsharp/soft if you are on a manual shutter and the fstop has reached it's max f11 and there is still to much light comming in. Either turn on a ND filter or spin the shutter up.

Macro is good with auto focus and so is tight shots and the subject is moving abit. Also sometimes I will lock the focus if on macro and zoomed max in and move the housing in and out with the subject to keep it in focus.

Exposure mostly on auto but with lights,night,shallow sand, macro, upside down manta, big animals comming past the still camera or tight shots I will lock it and fine tune. The camera's generally over cook things.

I'll send a film in this year Steve, if I can make a NTSC HDV tape. Have not worked it out 100% yet. A Z1 only records in NTSC or PAL when filming. It will not convert.

Wags...great input. Seems like we use manual exposure in similar circumstances...though I often mess up some of the footage trying to get it right in the moment.

Regarding infinity in full wide, what depth of field do you feel you are getting and how close to the subject before you consistenly lose focus?

Hey Wagsy,

NTSC HDV tapes are just fine for submissions. The problem with HDV is that now I have got to go back to everywhere in the world I've been and reshoot a rather sizable library of footage all in DV. Headed to the Phillipines this summer and then Bali here I come in 2007. Anyone interested in joining us?

Everyone is allowed to enter up to 3 submissions. For those experienced with festivals and competitions one thing you learn is that one never knows what a judge will pick. Even myself and the other 6 organizers of the San Diego Film Festival have to submit our films to the independent judges and you never know which ones they will go for. I've seen Howard Hall rate a film highly and Marty Snyderman rate the same film low. It is odd but thats the way it is. In 2005 my film Nocturnal Nebulous won the Stan Waterman Award and Best of Show at the International Beneath the Sea Competition and that same film didn't even merit an honerable merit at the Ohio Film Festival. You just can't allow yourself to get discouraged or to take things personally.

Everyone has a different way of setting their system up. Since I shoot always in manual, I will usually zoom into something, focus, and zoom back out. Now everything between the distance I zoomed into and where I back out will be in focus. Works practically every time.

Steve

You mean you guys don't have your finger on the manual focus knob to track your subject?

Infinity manual focus works for WA shots that are shot in constant distant to subject shoots. But once you have a subject moving toward or away from you...well... it does lack precision.

One of the biggest problems is the AF point is in the center. So for those shots with off center subjects... well AF will search abit. I tend to use AF 40% of the time. MF with my finger on the dial to track is also about 30%

As for manual exposure, I go by zebra 100% and then 1/3 or1/2 stop down from there. Obviously with WA changing light scenes, you're really stuck with auto.

Surely the 'no issue with infinity' and manual situation is a measure of your available light and depth of field - and also movement of your subject. It seems to me the conditions that Mike and Steve are shooting in (as described) are relativeley clear water, good light, and doubtless with good wide angle domes (with great DoF).

In the Galapagos last year I gave up on infinity and manual as the water was pretty dark (big aperture, low DoF), not particularly great viz (around 12-14m) I was using a w/a converter, not a dome (again lower DoF, lower light), and the hammers were everywhere from 20m away to touchable, and moving very fast. I wasted good footage struggling with manual; in the end WTF - changed to auto and shot my best stuff ...

Under different circumstances manual is definitely the better choice. I'd certainly use infinity on those long shots of mantas with good light, especially as there is normally plankton in the water with mantas around ...

What it comes down to is that a good and knowledgeable shooter is really prepared for all kinds of conditions and knows the ins and outs of his/her cam. So many simply point and shoot and don't bother to learn all there really is about filming, lighting or exposure and focus.

The boy scouts say" Be Prepared"

Steve

Hi Shawn

"Regarding infinity in full wide, what depth of field do you feel you are getting and how close to the subject before you consistenly lose focus?"

All depends on what fstop the camera is at, but in ideal conditions full wide infinity to about 1.5 meter infront of the lens I suppose. What can happen is if you are on auto exposure and a big aninmal comes closer, the camera thinks it is getting darker so will open up the aperture therefore making the DOV less, making the image softer/unsharp....

From 1.5m etc I will go to auto or zoom in, focus and pull back. With the #2 macro lens in you can really zoom alot further in from full wide on a subject like 1 meter away to it's eyeball, it's really cool.

STEVE..I have PAL FX1 HDV & A1 camera's so PAL HDV tapes....I ran the FX1 PAL camera out through my hardware composite converter to see if the PAL A1 will record the NTSC signal as a NTSC a DV one and vise versa. No go in fact the A1 cannot even record in unless it's firewire. The FX1 can record in but not a NTSC signal. This NTSC/PAL thing is so stupid in this day and age....... I can make a NTSC HDV file and send it back to the FX1 as NTSC but it's playback is jumpy due to the 50i/60i thing. I will convert the 50i to progressive then to 60i and try making a NTSC 60i file and send that back to the camera.

Great discussion. Just what I was looking for.

I would say that during the course of a typical Similans or Burma liveaboard my camera will only actually "hunt" say once or twice on auto-focus. The rest of the time it keeps mantas or whatever nice and sharp, even in less-than-great viz. Top marks to the VX2K/Gates port in this respect. I'll be totally screwed if I get hired with another camera that doesn't behave itself so well.

I reckon all this manual stuff must be a lot easier on the Amphibicos. The controls are all there on the Gates but it's always fiddly and time-consuming engaging one correctly amongst that little cluster of controls behind the left handle. After 1000 dives with this housing I still almost always need to look through the little window to get ND/focus/iris control right.

Scubadru, how do you adjust exposure by only 1/3 or 1/2 of a stop? My VX2K jumps from stop to stop (e.g. F4 to F4.8)... or is that not a full stop? I can't remember.

Wags I'm a bit concerned that the FX1 will not record to NTSC HDV through firewire. I was hoping to offer tape output of edited NTSC HDV as one of my services. I wonder if the Z1 is the same? I was puzzled why there were different PAL and NTSC versions of the Z1, and maybe this input restriction is the key difference, not just what format it defaults to for recording through the lens.

Nick

Nick, you can set up the Z to record either PAL or NTSC, the FX you need to purchase as one or the other.

What Wags and Stever are discussing is a little something from an older thread about submitting NTSC to a contest as Wags has a PAL FX.

Mike, Nick and others.

I was messing around today with some encoding.

From a HDV 50i PAL timeline I encoded out a NTSC 60i m2t file using Procoder then Aspect HD and then firewired it back to my PAL FX1 camera and also the PAL A1.

I then play it on my PAL/NTSC TV and indeed it was NTSC comming out of the camera.

It played back smoth this time but maybe abit down in quality but it was not jumpy so getting abit closer now to nailing it. It's interesting to see the PAL camera's kicking into NTSC mode as the 60i m2t file gets sent to it.

I also found that encoding out a NTSC mini DV file from the HDV PAL 50i timeline with procoder worked rather well and I was able to import the NTSC mini DV file and edit it no probs. From that I suppose one could encode out to NTSC DVD specs.

One of these days I'm going to investigate Twixtor software, which apparently can give the very smoothest results in converting between specs such as PAL and NTSC. Even better than Procoder apparently. I think you need something like After Effects to plug it into however.

Nick