Jump to content


Member Since 25 Oct 2013
Offline Last Active Today, 03:46 AM

Topics I've Started

Color Correcting Purple Water

20 October 2016 - 08:31 AM

I've noticed that a number of cameras, including my current Sony A7RII and former GH4 tend to turn water an ugly purple color when custom white balancing at depth, with or without filters for assistance.


As best as I understand it, this is because they push the red channel a bit too much in order to give a pleasing appearance to the foreground objects and make the white balance slate actually white.


One approach to combat this might be to introduce some red/magenta into the white balance slate itself.


But it seems it's possible to adjust the magenta in post as well. Here's the results of my initial test using ColorFinalePro in FCPX and playing around with the blue slider is the 6 vectors. The footage comes from Backscatter's review of the Sony A7RII and was initially exposed using a orange filter and custom white balance, I believe. 




If anyone else has insight on how to improve on this, please share!

Tokina 12-28mm f/4.0 AT-X Pro DX Lens

07 September 2016 - 10:52 PM

Has anyone used this underwater? What are it's characteristics behind a 170mm, 200mm or 230mm dome?


On paper, the range seems perfect for 4k video on the Canon 1dx II, which has a roughly 1.3x crop -- effectively making this a 15.6mm-35.6mm equivalent lens.


Canon's own EF-S lenses can't be mounted on the full frame bodies, and the full frame wide angle lenses are too narrow (other than the 11-24mm, I suppose, but that's a beast!

Nauticam 180mm/Zen 170mm domes with fisheye lenses

03 June 2016 - 09:06 PM

Has anyone used either of these two domes with fisheye lenses on a full frame or APS-C camera? How was the performance and image quality if so?



My understanding is that both these domes are designed for wide angle lenses rather than fisheyes, so the angle of curvature is different -- they're slices from much wider diameter domes. How would this impact their use with fisheye lenses? Am I going to get better image quality with a smaller fully-circular dome like the Nauticam 140mm dome or the Zen 100mm dome?


Use case -- Canon 8-15mm lens w/ or w/o 1.4x teleconverter an a Sony A7RII camera. Potentially the Tokina 10-17 with a Nikon D500 in the future. I'm trying to find a dome that's a good balance in terms of image quality, price and size for travel.


I'm currently using the Nauticam 8.5" dome and I'm happy with the image quality at F8 or narrower (usually shoot around F11). But the size of the dome is a little inconvenient for travel, not to mention that it makes the camera a little too positive at the front (have to counteract by strapping a 1kg weight on a weight belt around the dome port extension). One further advantage I see to the 170mm/180mm domes vs a 140mm or 100mm dome is that they would make shooting over-unders a bit easier. 

2x Seacam Seaflash 150 (Nikon) For Sale

10 February 2016 - 02:44 PM

I have two Seacam Seaflash 150s for sale.


Made with Nikon and come with two Nikonos 5 style electrical sync cables. 


Looking for $1300 each + shipping.

Back to full frame -- A7RII vs. D810

25 November 2015 - 06:11 AM

I bought a GH4 last August intending to do 4k video after flooding my old D800. Found out I prefer photography. After using the GH4 for a year (Nauticam system), I find that most of the time I take stills. Currently, I shoot underwater every day. I'm based in Thailand and I work on a day boat where I shoot, and sell images to, tourists trying out scuba diving for the first time, doing courses, or just fun diving on our boat. You can see some of my stills at www.andreiv.com to give you an idea of what I like to shoot.


I'm 90% convinced that I should get a full frame camera again to address some of the shortcomings of the GH4. For the past couple of months, I've been mulling about whether to go with a D810 or A7RII setup. I would probably buy two bodies down the line -- one to stay inside the housing, and one as a backup/for topside use.


I'm hoping for some wise guidance to sway my decision. I've highlighted questions in bold/italics. Please also correct any mistaken assumptions I have.  


1.  Gear I Currently Own

  • Panasonic GH4; Nauticam GH4 Housing; Panasonic 8mm Fisheye (w/ Zen 100mm glass dome); Panasonic 7-14mmF4 (w/ Zen 170mm glass dome); Panasonic 14-42mmPZ (w/ 35mm port); Olympus 60mm macro; Nauticam SMC and Inon +6 Diopter.
  • Nauticam D800 housing; Sigma 15mm lens (Nikon Mount) (w/ Nauticam 8.5" Acrylic dome -- needs new acrylic element).; Nikon 16-35mmF4 (w/ port extension for use with 8.5" dome); Nauticam port for Nikon 105mm macro. But no body or 105mm macro -- both were lost in the flood. 
  • Nauticam 45* Magnifying Viewfinder
  • Nauticam Flip Adaptor
  • 4x Sea & Sea YS-D2 strobes with CM Diffusers; Retra LSD Prime Snoot
  • 2x Archon 5000 Lumen Video Lights


2. Limitations of Current GH4 Setup Driving Desire to Upgrade (in order of importance, roughly)

  • No ability to use a large dome with the 8mm fisheye for split shots. (Action) split shots are hard with the Zen 100mm dome. 
  • 8mm fisheye is too wide at times for environmental portraits of divers. Ideally, I would like a fisheye (zoom) option that covers the 180* to 100* or even 80* FOV range. Or at least a wide angle option with less corner distortion. 
  • Distortion on the 7-14mm in Zen 170mm dome is unpleasant, especially the way it stretches objects towards the corners at 14mm, so I don't like shooting with the lens. Looking back at my old pictures with the  Nikon 16-35mmF4 doesn't show the same problem. Is this because of actual distortion of the lens, or perspective distortion because 7mm is so wide?
  • Not able to use teleconverters (to limit the field of view of the 8mm fisheye, primarily) 
  • Unreliable subject tracking in AF-C for focus & recompose technique. I miss the D800's 3D tracking for macro/fish portraits. 
  • Limited depth of field control for topside images
  • Limited ability to track/shoot wildlife topside
  • Limited manual wide balancing for wide angle ambient light video. I find the video looks a bit brittle, the colors artificial, and the water column too purple. 
  • Noise in ambient-light 4k wide angle video (manually white balanced) at ISO 400+; ISO 800 barely usable. 
  • Can't quickly zoom to 1:1 on the focus point in image playback in order to judge focus?
  • Limited ability to kill the ambient light for shots with black backgrounds (because max flash sync is 1/250, min ISO is 200 and diffraction is an issue past F11--with F22 being a hard limit on m4/3 lenses)
  • Olympus 60mm macro has too tight a field of view, focus is slow. I haven't tried the Panasonic 45mm or 30mm macro options, but suspect the working distance is too limiting compared to full-frame macro options?

2. Things I Like About the GH4

  • Size/weight of the system
  • Being able to compose with either back lcd or EVF w/ Nauticam 45* viewfinder
  • Exposure/white balance preview in EVF/lcd along with focus peaking and zebras. I love being able to see what the background exposure will look like before I take the shot, letting me focus on composition and waiting for the peak of the action
  • Accurate contrast-detect focusing -- no issues with PDAF mis-alignment
  • 8mm fisheye sharpness, close focusing ability inside the Zen100 dome for CFWA/WAM
  • optical flash triggering & TTL with ys-d2 strobes using internal pop-up flash
  • battery life sufficient for 3+ dives without switching batteries


So with that background in mind, let's talk about how the D810 and A7RII would or would not address my wants.


3. Shared advantages of D810, A7RII

  • Full frame sensor -- better noise, dynamic range, color depth, depth of field control
  • Can use a fisheye zoom to cover at least part of the 180*-100* FOV range, though both options seem problematic? D810 can use the Tokina 10+17 + 1.4TC for most flexibility, or the Sigma 15mm + 1.4x TC for a tighter field of view and better image quality than the Tokina. The A7RII with the metabones adapter can use the Canon 8-15mm + 1.4x TC in full frame or APS-C crop mode for ultimate flexibility and better image quality than the d810 w/ the Tokina 10-17 + TC, though you lose a bit of reach at the long end. 
  • Both can use the above  fisheye solution with a large dome like the Nauticam 8.5" acrylic or 230mm glass dome for easier split shots
  • Both have native 16-35mmF4 wide angle option that offer a more versatile field of view range than the 7-14mm on the GH4. Image quality is similar between the two?
  • Both gain at least 2 stops of ambient light control over the GH4 (for black backgrounds) because they have base ISO 100 and lenses can be closed down to at least F32. D810 gains 3 stops (base ISO 64, 1/320 flash sync)
  • Both can use teleconverters -- Nikon natively, A7RII on Canon lenses
  • Both have macro options (90mm on Sony, 105mm Nikon) that have a slightly wider field of view and better working distance than the Olympus 60mm


4. Nikon D810 Advantages

  • COST. I can convert my existing, D800 housing for $650, the camera body itself is $800 cheaper than the Sony, I already own all the lenses/ports except the Tokina 10-17 and Kenko 1.4x TC. Overall investment around $4000. 
  • Best flexibility controlling ambient light underwater (base ISO 64, 1/320 flash sync)
  • Slightly better DR at ISO <200. 
  • Better subject tracking in AF-C 3d tracking mode
  • Slightly longer reach using Tokina 10-17mm + 1.4xTC vs A7RII with Canon 8-15 + 1.4xTC
  • Can shoot 6 frames/second in DX mode vs only 5 for A7RII (with native lenses - 3 with Canon lenses)
  • Can be used to shoot wildlife topside (better autofocus, many longer lenses)
  • More rugged, better weather-sealing than Sony
  • Has a 60mm macro option for fish portraits
  • Excellent battery life that will last at least 3 dives
  • Pop-up flash allowing optical flash triggering with TTL
  • Great ergonomics topside -- the camera just feels right in my hands
  • Better selection of native lenses, primes and zooms, at more reasonable prices than the Sony primes


5. Nikon D810 Concerns

  • No 4K video; video white balance for 1080p underwater poor. Would need to keep GH4 system if I want 4k video (undecided).
  • AF-S less accurate than Sony/Panasonic because it's off-sensor PDAF
  • No electronic viewfinder; no focus peaking; no live exposure preview; no zebras; have to review LCD after each shot for exposure
  • No ability to shoot at arm's length using back LCD; must have face against the viewfinder.
  • Unacceptable image quality with the Tokina 10-17 + 1.4x TC?
  • System is about 2kg heavier than Sony, 3kg heavier than Panasonic. 


6. Sony A7RII Advantages

  • Great 4k video, both in full frame and APS-C crop, great versatility (it's essentially both a full frame and APS-C camera in one). No need to keep the GH4 system.
  • Widest AF-point coverage; complete frame covered when shooting in APS-C mode?
  • Accurate AF because PDAF points are on sensor and used in conjunction with contrast detection
  • Full viewfinder image when shooting in APS-C mode; 
  • Better DR/Noise at ISO 200+, where most wide angle shots will be taken
  • EVF with focus peaking, live exposure preview, zebras
  • Able to shoot/compose at arm's length using back LCD
  • Only 1-2kg heavier than Panasonic; lighter than Nikon. 
  • Can use adapted Nikonos water-contact lenses for best image quality, smaller size
  • Can adapt pretty much any lens (great for things like Canon tilt-shift lenses, unusual lenses like the Venus Laowa 15mm 1:1 Macro Lens)
  • Has wifi, can be controlled over wifi


7. Sony A7RII Concerns

  • COST. Would have to invest about $10k for body, housing, adaptors, ports, zoom gears, 8-15mm lens, teleconverter and 16-35mm lens. That's $6000 more than the D810 system. Could recover maybe $3500 of that from selling the D800 items I have. Cold also recover $5000 or so from resale of GH4 system. 
  • Subject tracking no better than the GH4 (in other words, not reliable enough to use, unlike Nikon's 3d tracking)
  • No native fisheye option. Not clear how well the Canon 8-15 + metabones adaptor would work as substitute. Sony 28mmF2 + fisheye converter lens is bulky and heavy, not as good image quality as the Canon 8-15 behind a dome? Sony 28mmF2 in flat port with Nauticam WWL-1 seems to have good IQ, and a FOV roughly equivalent to the Sigma 15mm + 1.4x TC? However, that option doesn't allow for a large dome port for split shots.
  • No native 50mm or 60mm macro lens for fish portraits
  • The white balance for ambient light video is just as problematic as the GH4 and requires red filters
  • Not great for wildlife topside (lack of lenses, evf, slower FPS).
  • No pop-up flash -- need Nauticam flash trigger or electric sync cables; no option for TTL
  • Battery life may not be sufficient to last 3 dives, requiring switching batteries on the boat
  • Weather sealing is not as good as Nikon's / the GH4
  • Ergonomics are not as good topside as the D810


8 Wildhorse Contestants

  • I could just stick with the GH4 and buy the WWL-1 to use in conjunction with the 14-42PZ as fisheye-zoom of sorts. This would cover the 130/120* to roughly 80* field of view, eliminating the need for the 7-14mm, which I dislike? Cheap option-- only $1200 investment. BUT this wouldn't address the lack of a bigger dome port for split shots, noisy 4k video, purple white balance, limited depth control topside, limited wildlife shooting ability. Can anyone thing of some solutions, especially for using a bigger dome on the GH4?
  • Go with an APS-C option like the Nikon D7200 or Canon 7DII to avoid the lack of a native fisheye zoom on full-frame. But does a dedicated APS-C camera really offer any advantage? -- after all, both the D810 and A7RII can be shot in APS-C crop mode with comperable image quality, and once entire system costs are computed, there is a minimal cost saving in going with the D7200 or Canon 7DII over the full frame bodies.