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rcolman

Diopter Choices

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I am going to attempt some "macro videography" for the first time with a Canon HV30 behind a dome port on an Equinox housing. I know most use wet diopters in front of flat ports, but, what the heck.

 

I am planning to use dry diopters, attempting to get some nudibranch footage. The set consist of the usual +1 +2 and +4. Since I can't manual focus and the little inboard monitor wont really show focus too well and since there is no autofocus lock indicator, etc. etc.

 

What combination of dry diopters would you recommend, and where shall I place the lens in its zoom range?

 

Sage advice appreciated.

 

Rick Colman

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I think I would probably start with the +2, zoom all the way in, then pull back until (if) the subject comes into focus.

 

I would probably forget the +1 or any stacked combination and try the +4 if the +2 works.

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I think I would probably start with the +2, zoom all the way in, then pull back until (if) the subject comes into focus.

 

I would probably forget the +1 or any stacked combination and try the +4 if the +2 works.

 

 

Well, I tried a stacked combination of +6 (2+4) in the bathtub, and it seemed to give me nice coverage of a 3 inch simulated nudibranch - using the zoom cranked all the way out to full wideangle. Keep in mind that this is behind a dome port.

 

Not aure about exposure ... whether to leave it in full automatic. My still photography sense tells me to pu into aperature priority, crank it down to about F4 (half way in between f.18 and f8 and shoot it that way.

 

---> I am concerned that I will not have enough natural light at depth (no video lights yet).

 

rick.

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I'm wondering how you simulated (stimulated?) that 3 inch nudi in the bathtub :lol:

 

Re exposure, video is different from stills. If there's any significant movement you'll most of the time want to fix the shutter at 1/60 if you're shooting 60i, 1/50 if you're shooting 50i, or 1/48 if you're shooting 24p. But if the camera is locked down and there's little movement (e.g. nudi) you might be able to use slower shutter speed to give you more light, instead of using too much gain which would introduce noise. If there's movement (e.g. juvenile reef fish) then slower shutter speeds give you a "strobey" effect (try that in the bathtub). Faster shutter speeds miss some of the action and you'll get a slightly steppy effect, so I prefer to reduce light with ND filters if I need to. But again if there's little movement then a faster shutter speed is not a problem.

 

F4 is a nice sweet spot to aim for. Much bigger iris would give you a shallow depth of field, which can be nice for making your subject stand out against a blurred background. But with diopters the DOF can be just too shallow, like just a few mm sometimes. Smaller iris like >f6.8 can start to make the image degrade.

 

With lights I generally shoot macro by locking off the shutter at 1/50 (I currently shoot 1080-50i), the gain at 0dB, put the iris in auto to let it do it's thing, then put it back into manual and perhaps stop it up or down a bit depending on how the image and zebras look.

 

Would be interested to see a still of how the image looks with your stronger diopters behind a dome port.

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Would be interested to see a still of how the image looks with your stronger diopters behind a dome port.

 

I tried a +6 dry diopter combination and it worked out well behind the dome port. I was able to fill most of the frame with a 3" nudibranch with good focus. I left the lens at full-wideangle behind the dome port. The combination seemed to work ok. I then tried a +2 diopter on the second dive, and this did not have much effect. I can't recommend this low diopter as being much good.

 

Exposure is still a problem. I decided to go back to automatic "cine"mode on the HV30 which is full autoexposre with low gain with the shutter locked at 1/60. Unfortunately, I was deep in cold southern california waters with littel light. The footage is viewable, but undereposed a bit.

 

Next time I will try locking the exposure at f4 in aperature priority, or, better yet, mabe bring some lights.

 

rick colman

laguna hills, ca

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I had the century +1, +2, +4 kit for my previous camera (JVC HD10US) and I thought the +4 and +2 stacked was good. I bought a similar kit for my Sony HDR-HC7 but have since switched to using a +10 diopter (made in India I think??). You can see my recent macro shots here www.mydivinglife.com/ScubaBob. You can scroll through the different dive reports, but several of my last dives were Nudi-dives - and all were using the +10.

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How is the macro hunting going Rick?

 

Also - does anyone have experience using the Raynox MSN-200 or MSN-505 macro lenses with the HC7 or other HDV camera? Results?

Edited by ScubaBob

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How is the macro hunting going Rick?

 

We do a lot of macro photography in southern california, because, dive conditions are often too poor for wide angle, and fish or other larger scale marine life is scarce.

 

I have been doing some video macro, but, unless the nudi is actually doing something, it is like trying to do a video of a pretty rock or something. Not really much action and, to my taste, still photography is better suited to nudibranchs, etc.

 

I have, however, invested in some dive lights, so may take it up again soon

 

Rick Colman

Laguna Hills, CA

www.colmanphoto.com

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I definately like photography for macro to be able to see the detail - but I really do like shooting video of nudi's and other macro subjects. Even just a moving rhinophore can be make the shot interesting. I just finished compiling footage from my last macro dive (a little shaky, and forgot to deinterlace...)

 

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