41 replies to this topic

[CamDiver]

Hi Guys,
Thanks for the positive feedback:

- Drew -
I took all of the information regarding kelvin and CRI from the different web sites of the mentioned manufacturers. There are variances even within a specific lighting characteristic such as HMI from one manufacturer to the next, same with CRI. Nothing is created exactly identical. Thanks for 'correcting' my mistakes.

- Jules -
Is that an achromatic diopter or single element diopter? Century? Made for the Z1?

- shawnh -
The great thing about macro is that you can shuffle into position, take a while doing it and for the most time the critters stay in place. There's only so much of a magnification you can get away with when hand holding the rig, after that you need some kinda stability. This is where your own ideas come in to play. Rather than look around for a manufactured and ready made piece I'd suggest rooting around for some old articulated strobe arms or other bits and try looking at 'McGyvering' something together that will allow you greater stability with reduced environmental impact etc.

Cheers,
Mark.

[Drew]

Mark
It is I who made a mistake. The 200W on the Halcyon uses the Osram HMI W/SE bulb which is 90 CRI.
Xenophots are halogen incandescent bulbs from Osram/Sylvania. Incandescent/halogen bulbs all have 100 CRI. There is no variation as they are used as the reference source for CRI.
I'm merely trying to add to what you have written and not correcting you in any way.

[videodan]

Good writeup Mark. I have been looking into gyro stabilization for macro and general shooting. I know many of you may also be interested in this. Kenyon Laboratories makes gyro stabilizers for broadcast cameras for helicopter and boat shoots, and general shooting where a stabilizer is needed. I spoke to Ron at Kenyon about underwater video shooting, and he told me there are many users of their products underwater already. He told me the gyro itself is waterproof and has been used in the Mariana Trench, and in outer space. The powerpack is the only thing that needs to be waterproofed, and he said many have done this already. I will probably rent their smallest unit to see how effective it is and report back. It should work great, as my housing is near neutral. The gyro should easily mount to the tripod mount on our housings. The only thing I'm uncomfortable with is that they are all 115v.AC powered. Maybe the inverter has a breaker built in, will have to find out before I kill myself. Check out: http://www.ken-lab.com/index.html
Dan

[MikeVeitch]

come on Dan.. whats a little death when contributing to the greater good..

[videodan]

Oh all right, I'll be the guniea pig.
Dan

[CamDiver]

- Hey Drew -
You still ain't gotten used to my directness huh? It'll come. I wasn't reacting to your comments negatively. Thanks for the input.

- Mike -
Right on mate. Hey are those Mandarins still in place since I stapled them to the reef to make that short? Maybe they decomposed already eh? If so I found it best to get 'em behind the ear, almost painless.....

- videodan -
Great find! I'm looking into it......cheers for the heads up.

Best,
Mark.

[Jules (Helioxfilm)]

It is a B+W designed, single element 72 mm diopter

http://www.schneider...iten/filter.htm

("Nahlinse", look at the bottom of the page).

[CamDiver]

Jules,
Single element. I'll never go back to using these. If you ever get the chance to use an achromatic diopter take it. I stack a 3.5 and a 2 these days with hardly any real image degradation, there's some but not discernible to the untrained eye.

Cheers,
Mark.

[Drew]

Dan, stabilization is a nice idea but there are a few things to consider.
I've used those things in aerial shots and they make some noise due to the motors. Underwater, it would be very loud and may scare marine life. On the other hand, it'll attract all the sharks (inverter and and motor noise) if there are any around where you're shooting.

[videodan]

Drew, did you use the Kenyon Labs gyro or another brand? Also, do you think it would work well underwater, especially for macro? Last question, how loud and what kind of noise did it make? I'm still kind of leary about 115v.AC anywhere near me in the water, so I'm not ready to order one yet.
Dan

[Drew]

I believe the one used for the aerial shot in FL was a Kenyon, looked like it.
The sound is a whirring of the motors, I can't give you decibels but I could definitely hear it (well before the chopper started that is) and in water the vibrations will come through.
I'm not familiar enough with the accelerometers and how sensitive they are to movement in water to guess if it is effective. I will say that even with a gyro stabilizer correcting for the X and Y axis, there will be variances in the Z. You will also get the perspective change as camera moves anyhow. I was having lunch last week with a guy who built his own stabilization device for an Arri 435 using a few parts from Sachtler to shoot breaching great whites and even he say there's no cheap way to adjust for perspective changes, just XY axis changes. For extreme macro underwater, if you must shoot in natural environment vs setup stage/fishtank, the tripod is the best option. If it's in an area that would cause too much damage to coral... well... find another place that won't!
115v won't kill you... you may however soil your wetsuit somewhat.

[CamDiver]

Response back from some film peeps in Hollywood was that this unit, or units from the same company, were used for some of the Star Wars trilogy 'flight simulation' shots. Also it was used on some other big movie. One of the operators told me that it takes a few minutes for the gyro to get up to speed and then can be disconnected from the battery and will need a zap to maintain its speed possibly every 5 minutes or so. It still means carrying around a pretty substantial battery for this even if it could be adapted for underwater use. I think after all is said an done the hassle, expense and weight alone outweigh its possible benefit. Better stick with a good tripod. IMHO.

Cheers,
Mark.

[Brumpy]

Mark,

This is really intresting.
I have won Antibes in 2005 with a film full of macro shots "Disguise and Deceit on the reef", this is done with a PDX10 in a bluefin housing from LMI with a special External Macro lens.
Now i am filming with the FX1 with again a housing from LMI, the housing have a internal macro filter that is really nice, but i like to go a litle closer and closer ofcourse :-)
So what i like to now if the diopters going to do the job better? what do you think? they cost almost 500 euro each so if i buy the 2 that is 1000 euro before i know if the result is better.
I will be in between Ambon and Raja Ampat for 3 weeks in Oktober (full of all kinds of Pygmee's etc).

[CamDiver]

Take a look at my Blog which is linked in my signature below or on my flickr page. There are lots of stills posted from macro subjects. Take a look at the edges to see the huge difference in chromatic aberration between using single and multiple element diopters.

Cheers,
Mark.

[Jules (Helioxfilm)]

Hi Mark,

I was checking the Century Optics website. These diopters seems to be quite large (in depth). Are they fit to the housing? Is there enough space? Or you have to use the dome port?

Jules


Update: Just reading back to your original thread. So it is 'hardware' dependent...

Edited by Jules (Helioxfilm), 11 August 2007 - 11:19 PM.

[CamDiver]

Hi Jules,
Having a big computer clear out at the mo so I don't have the images I took of the camera rigged up with the Diopters inside the flat port.

Here's a shot with the two diopters stacked. They each have a profile depth of 18mm. The front edge of the front diopter must be pretty much touching the glass inside my flat port but it fits, just. So yes it is a hardware issue. The image is to show the difference in size between the achromatic and single element close up filters / diopters.

Cheers,
Mark.

[Cathay Stray]

Well I guess it was long overdue,

I've often been asked about my filming techniques (.........................)

Hope this helps,
Cheers,
Mark.
P.S Check out my flickr page (link below) as I'll be constantly adding new video stills from this recent trip.

Mark thanks a lot for an extremely interesting and useful story. Now, how do you do the lighting at macro settings? I mean, the distance between the port glass and the subject is nearly zero, "keep it dark" rule hardly works in such a situation, not everyone has a ring strobe... any advice?

I am a complete novice and this is not the last naive and silly question I'm going to nag you with

thank you

Mark

[CamDiver]

Hi Cathay,
No problem, the pleasure is mine. With lighting, seeing as this is video and not photography I don't use any kind of circular or ring strobe. I'm using HID underwater lighting supplied by Green Force, in fact the Squid 250 HID's. The light itself is way too severe for direct light onto the subjects so I have both light heads in a position so as to bathe the subject in the peripheral light of the respective beams. By making slight adjustments, with the camera settings and light angles, the subject can appear as bright or as shadowed as required.

Cheers,
Mark.

[wagsy]

Speaking of macro.....I had to use macro +4 and +1 diopters together last night as Kelly got a tick stuck in her leg from camping in the scrub.

[jonny shaw]

I'm sure Kelly loves you posting her ticks on the internet!!!!!