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Tom_Kline

Member Since 07 Nov 2004
Offline Last Active Today, 11:34 AM
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Posts I've Made

In Topic: Custom white balance and noise

18 January 2017 - 10:45 AM

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Your pix are not too bad. I grabbed the jpegs you posted and imported them into Lightroom to do the tweaking. The second shot that you AWB got only a tint adjustment (green-magenta slider) in the way of color balance change from me so color temp may have been OK via AWB. AWB may ONLY do color temp and no tint adjustment - ask Sony not me!!


In Topic: Performance of Sigma 12-24mm ART underwater?

16 January 2017 - 05:25 PM

I guess this is such a new lens that nobody has tried it yet....

It has a large diameter which makes a quick test with a rented unit not possible for many. One needs a port with a large throat diameter as well as a large radius of curvature (superdome class). That said I am very curious about its performance as well ;->>


In Topic: Advice for a beginner?

16 January 2017 - 01:32 PM

I agree with what Tim says in post (#13), however, I prefer to use a straight finder for most dives but prefer a 45 degree finder when snorkeling as they are easiest used while in a prone position. Similarly for a dedicated muck dive (just off the bottom).

 

I have used them (45) as well for very shallow pix such as semi-submerged at the edge of a stream but it can be tricky positioning the housing so the finder can be used (dry in my case). I dug up some pix from 2011 showing this. One housing has a 45 finder on it the other the standard finder. I used the 45 finder to better aim the camera and to make sure none of the focusing points were on a nearby rock. I was just able to lie behind the camera to look through it. Actual photography was done using remote control via the cables you see in one of the pix. I was on a wider "beach" just downstream of where the cameras were to do the shooting.

 

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These finders are generally made to fit specific housings. Some such as the Seacam's are easily swapped out (think camera lenses). You will have to research your particular housing model.


In Topic: Distance from dome port to lens? Can I get away with being 20mm out?

16 January 2017 - 01:24 PM

My friend Eiko Jones in BC made some great over unders with a... ready for it... macro lens. He shot them in a swamp and got some amazing shots of little frogs sitting on lily pads. I suspect that he has them posted on his website someplace...

 

Once I saw those, I realized that just because "they" say it can't be done, it doesn't mean it can't be done...

It would be nice to be able to actually see these pix. Getting both the air and underwater parts in focus at the same time (not using Photoshop!) is not that easy. To use longer focal length lenses one can use a split diopter lens - like a regular diopter but only covers one half of the lens so that one can focus at two distances. It is possible this is what your friend used. There is a bit of trial and error using split diopter lens with getting the subject to match the two distances. I failed the last time I tried.


In Topic: Distance from dome port to lens? Can I get away with being 20mm out?

15 January 2017 - 04:36 PM

Getting the best fit behind a dome port is often a matter of trial and error. Maybe starting with the recommendations of the housing manufacturer and varying the amount of port extension (it helps to have several port extension tubes on hand). Most successful over-under shots have been done with fisheye lenses. I am not familiar with your gear so cannot provide more specific directions. Keep in mind that if the lens is squat very little if any port extension is needed. It is the longer zoom wide angles such as the more recent Nikon and Canon 16-35 lenses that are quite long and require a lot of port extension. The older primes used hardly any. The old Nikon 20D lens requires none (Seacam) for example.