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Undertow

Member Since 05 Dec 2006
Online Last Active Today, 08:34 AM
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#399468 Help: Strange circles in pictures

Posted by Undertow on 18 September 2018 - 10:45 PM

I shoot a lot, including tons of blue water whale images and I've never seen a reflection like that. Reflections come from sunlight hitting the front of the lens and reflecting in the dome port. You only ever see a section of the lens, not an entire circle. You'd have to shoot with the sun dead center in the frame for that to be possible. 

 

I'd agree with troporobo - my best guess is post processing artifacts. It happens with blue water images quite easily. 




#398535 D500 vs D850?

Posted by Undertow on 20 August 2018 - 11:24 PM

What are your reasons for the D850? Just wondering/looking for something that will help me decide.

I wish I had time for the upcoming mirrorless to come out and be proven, housing and such, but I dont.

Thanks,

 

Well I haven't read through this thread, perhaps this has all been said but...

 

D500 

1. Smaller, which translates to significant size/weight reduction in housings. Its under-appreciated but very important - it will handle better in and out of the water. 

2. 10fps would come in very handy in some shooting situations - I wish I had that. 

3. In a certain sense it has better magnification/DOF for macro - though one can crop a D850 file to nearly D500 dimensions, but it would change your shooting style. 

4. Its much cheaper, as are some housings.  

5. Rectilinear super wide lenses will perform better behind the same size dome. Soft corners are a real challenge.

6. If you prefer fisheyes, the Tokina 10-17mm is a DX gem that has no FX equivalent (perhaps the new 8-15mm + kenko TC).

7. It really is right up there in quality - I've shot it alongside my D810 topside and its brilliant, the price difference does not reflect an overall image quality difference. Better value for money. 

 

Why I'd personally go D850:

 

1. I want the highest resolution possible - I've had my images blown up to full wall size (7+ meters across) for up-close viewing. Every pixel matters then. But honestly the 12mp from my old D700 is plenty of resolution for 99% of things.

2. I'm set with my full frame lens lineup. I'd have to buy new lenses (superwide zoom, 40mm macro as I love the 60mm view on FX). 

3. Marginal edge in dynamic range (0.8 stop by DXO's measurements). It means nothing for 99.99% of people and situations, but I often push my camera's boundaries. I've managed some impressive high contrast shots with the D810, but I shoot some weird stuff. 

4. I do love my 16-35mm on the D810 - its my go-to lens (but only behind Aquatica's 9.25" megadome). Perhaps the 10-24mm or some other lens on a D500 would perform as well or better but I don't really know (yes I'm sort-of contradicting #5 above... with a smaller dome D500 would win)

5. I shoot topside more than UW and would prefer the D850 there. 

 

Mirrorless:

 

1. Hugely smaller & lighter. World of difference.

2. Come such a long way, with the right setup (quality body & lenses) most people would be hard pressed to tell the difference from a DSLR.

3. I generally tell people today that unless they know they want an SLR, if you have to ask yourself the question, just go mirrorless.

 

Hope that helps. Cheers,

 

Chris

 

Edit:

Oh and just looked at some of your work. Awesome stuff. I see you shoot some action sports too - I'd go for the D500 hands down for that. 




#395138 What is wrong with my settings (Sony rx100iv )

Posted by Undertow on 06 May 2018 - 01:37 PM

Have to disagree with Mike and undertow.  Your shutter speed is slow enough for the strobe to fill the scene. I would tend to agree if you had a shutter speed that was faster than your strobe (ie 1/250 or faster) but slow is not usually a problem.  See my photo below with same shutter speed both upclose and wide angle (shutter speed 1/100-1/160).  I do agree that you should shoot in M mode. 

 

I think you've misunderstood Mike and I. What we said has nothing to do with the strobe syncing with the camera (i.e. having too fast a shutter speed).

 

This is basic exposure stuff. When using strobes, you're mixing 2 forms of light:

 

1. Strobe Light

- strobe exposure determined by combination of strobe power and aperture

 

2. Ambient light from the sun

- ambient exposure determined by combination of shutter speed and aperture

 

In your excellent images, kdgonzalez, if you erased the strobe light (if your strobe didn't fire), they would be very dark, very underexposed. The eel image would likely be black. That means you have a dark ambient exposure. The issue with the original poster's images was that the ambient exposure was way too bright to begin with. 

 

There's no room for disagreement here, this is 100% true. 




#394364 Weight difference between DSLR and Mirrorless

Posted by Undertow on 12 April 2018 - 03:55 PM

Yes, huge difference, depending on setup. I generally tell people today if you don't know you want an SLR, go mirrorless. 




#394287 Best backpaak or hard case suggestions

Posted by Undertow on 10 April 2018 - 09:29 AM

Think Tank Airport Security v2:

Definitely a 'max' size bag, fits a ton a stuff, and I've flown successfully with it all but once. Cathay Pacific got me with a weight limit of the bag empty! So I carried gear on my person (photo vest stuffed full, sling camera) and swapped housing to my gf's carry on etc. Took the bag on the plane almost empty. 

I do find the sides like to bow out so I have a pair of straps I wrap around it between check in and boarding so it doesn't look too big. 

 

Lowepro Whistler 450:

Just got this free, great Lowepro warranty, and agree with Aotus that it's heavy but carries well. Gear capacity is maybe 2/3 of the Think Tank roller + has outer compartment too. While no laptop slot, my 15" fits perfect in that outer 'wet' compartment, but I'd remove it before laying a loaded bag down to access gear. Works while flying though with a small laptop bag packed in my suitcase. 

Its surprisingly narrow but its designed to carry skis etc on the sides. But that meant, when boarding late, I fit it fully loaded into a tiny overhead space last flight while people with much smaller rollers were lugging them back to the jetway to gate check on the full flight. Massive win. 

Bonus: The camera box can be removed. Next non-photo trip I may use it as a normal bag. I've also seen someone put the box into a normal small roller, converting it to a camera roller for travel. 

 

Kata CC-195:

Seems this no longer exists and Kata's been absorbed by Manfrotto. Designed as a pro camcorder bag, its shape is brilliant with a square cross section, and fits a 9" dome standing up as well as my laptop (in a padded sleeve) laying on top of the dividers holding the housing/strobes etc. Just wish it was a roller, would be my go-to for travel with the dome. 

 

I also have 2 old Pelicans (I think 1550) that I don't travel with but are great for the boat here, where I do most of my diving/photo. Wish they were rollers though. Seriously would consider the 1510 or 1535Air. 

 

Personal item is either Lowpro Flipside 300 (older version) or Photo Sport 200. The flipside is my go-to daily small camera bag (handles an slr + pro lens trinity very well). The Photo Sport is great for mirrorless gear or a subset of dslr gear. Fully expanded it can carry a ton of stuff, even my 15" laptop, yet it can be cinched down super small for activities like skiing. 

 

Cheers,

 

Chris

 

Edit: Just thinking about this. Of the 3 bags I described, all can fit straight-in into an overhead bin, but the Think Tank (and rollers in general) are wide, taking up a lot of space across the bin while leaving a big gap between the top of the bag and the top of the bin. The CC-195 and Whistler both have rather square cross sections utilizing the space all the way to the top of the overhead bin and much less width across the bin. This can easily be the difference between having to gate check or not on a full flight. 




#393844 What's wrong with my settings ? (Canon g7x mark II and Inon s2000)

Posted by Undertow on 27 March 2018 - 03:04 PM

Ok wow...

 

Please forgive my cynicism but 11 replies and no one has mentioned the primary issue here??? Apologies guys, but some of these replies are just confusing the situation. 

 

 

Laroux,

 

Your ambient exposure is too bright.

 

Your strobe clearly works, but the TTL circuit sees plenty of exposure from the ambient light and doesn't 'need' to add much to create a 'properly' exposed image. Dial down your ambient exposure. 

 

Also, as mentioned, you need to be a bit closer for best results but decent images can be had at your shooting distances. 

 

White balance is also way off. If your files are raw, crank up the magenta in post and you'll see a difference. For the future, start with the camera's 'Cloudy' white balance (usually a cloud symbol). 

 

Plan a dive to sit in one spot for 15+mins and experiment with exposure and flash settings. Set everything to manual and play around. Find what works for a given subject (even just a rock...) then switch to TTL and see if you can replicate it. 

 

Cheers,

 

Chris




#393829 Dual Ultralite Arm Set up?

Posted by Undertow on 27 March 2018 - 08:15 AM

I'm not sure what you mean, why not just adjust the lights' position? That's what movable ball joint arms are for... No single lighting position is applicable to every shooting scenario. 




#393146 Halation Problems

Posted by Undertow on 09 March 2018 - 10:17 AM

Looks to me like a post=processing issue.   Can you tell us how your images get processed?   In-camera settings?   Any customization done to the camera settings?   Are you using D-lighting set on high?

 

Sorry but its definitely not a post processing issue.

 

To simplify my post above I'm 95% sure its condensation inside the port from overheating as the housing sits in the sun. This can happen very quickly if the port's uncovered but can still happen with the port covered. It can take a very long time to dissipate and be exacerbated by the cool water (greater temp difference b/w inside and outside of housing), ruining entire dives. 

 

Cheers,

 

Chris




#392295 Adapter Sea&Sea optical cables to Inon Z240\330?

Posted by Undertow on 11 February 2018 - 11:58 PM

Pretty sure this is what you mean:

 

www.divervision.com/howshot-fiber-adapter-for-inon-strobe-older-slave-sensor-FA-SS2IN.html?


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#392050 LED strobe trigger not enough power

Posted by Undertow on 05 February 2018 - 10:24 AM

I've found UW specific fiber cables quite thin and flimsy (and expensive!) so I've taken to making my own out of 3mm end glow cable, mounting it into the plug ends from a failed cable. There was a recent thread about this exact issue with S&S strobes & led triggers with a video someone posted making it work with a custom cable like mine. 

 

Fiber cable is super cheap. Cut, flame polish the end, mount into the plug and you're good to go. Someone else suggested dipping in boiling water & wrapping around a rod to create a coil in the cable. Plan to try that. 




#391626 Professional on dry land - Strobe insights

Posted by Undertow on 24 January 2018 - 12:08 PM

I've built my own FO cables as well. Seemed like a no brainer - existing ones I had were so bloody thin and flimsy and cost a fortune. When they inevitably failed, I cut the plug ends off and mounted them to some decent size end glow (or could use multi strand). FO cable is cheap. You can get the plug ends for a couple bucks from some of the UW photo shops. 

 

I understand how TTL makes everything underwater quite a bit easier but I am confident that with some trial and error, my experience shooting almost entirely with artificial light on land will allow me to work within the limitations of my camera setup.

 

I also work a lot with artificial light topside and I'm confident you'll be totally fine in manual UW. Its really not complicated, at least regarding strobe power, when you have experience working with these tools. 




#391460 Upgrading from D300

Posted by Undertow on 20 January 2018 - 12:15 PM

Get the D500 and keep your 10-17. That camera is a beast and the 10-17's versatility and compactness with a small dome is unrivaled underwater. Ignore the "FX are the pro cameras" mantra nonsense. Mostly came from Nikon ill-serving the DX line for a few years. 

 

I've shot a D500 alongside my D810 topside and would seriously prefer it for certain things like macro. Image quality is 100% up to par, though I don't pixel peep. 

 

If you can easily do that Type3 to Type4 conversion, Subal makes the most sense to keep ports and viewfinder. Otherwise if you're in Canada check out Aquatica, I'm on my 3rd housing since 2006 and they've been fantastic. Prices are very reasonable, perhaps more so from within the country. 

 

The other option would be to just switch to a mirrorless system like Sony or Olympus. They're so compact and image quality will still blow you away when paired with quality lenses. 

 

Cheers,

 

Chris




#391191 Best wide angle lens for Nikon D850 in Nauticam housing

Posted by Undertow on 12 January 2018 - 01:24 PM

This is ongoing issue in all photo forums above or below water, suddenly you have extra resolution and when you look at the corners at 100% in Photoshop you discover that the image does not look as sharp as the lower resolution older model, therefore the new camera causes poor corners.  In fact the corners are the same as they always were and the image will look the same if you downsample to 36 MP or whatever the resolution of the previous model was. 

 

The actual situation is you can't take advantage of that extra resolution in the corners because the lens does not resolve that well in the corners. 

 

Indeed, well articulated, but has it been definitively shown somewhere? Personally I just don't see it both topside and underwater.

 

All I've read are allusions to the idea on forums - primarily before the D800 came out in 2012. I've not seen much mention of it since (thought it was debunked) until here and now with the D850 UW.

 

Of course I've always been a firm advocate for using the best optics possible and when asked I advise people of the importance of lenses vs cameras (and of shooting vs fussing about gear). 

 

I can somewhat see the idea from a "get-the-most-from-your-high-res-camera" perspective but not that one's image will suffer due to some larger relative discrepancy between the sharp center and unsharp corners. That acceptable optics on a D810 (or even D700) may no longer be such on a D850. 

 

I shoot a lot and just haven't seen it. Though I'm not much of a pixel peeper. 

 

I can't recall ever hearing in the film days that soft corners were blamed on film having too much resolution power. 

 

I believe that the current best wide angle/dome combo for 36mp camera is also the current best combo for 45mp camera. :)

 

Agreed.

 

Cheers,

Chris




#390766 Clear UV Filters - yay or nay?

Posted by Undertow on 02 January 2018 - 12:36 PM

A big 'nay' to that one, both topside and UW. Not watched the linked video but I stopped using UV filters years ago. Even good quality filters can be detrimental to the image, seen it myself. Also, in many years of topside shooting, haven't yet felt the front of a lens threatened as to require protection.

 

Lens hoods however are a different story. When you drop your camera, as I've done multiple times, it will impact on one corner of the body and on the front of the lens. A hood will save the lens. An L-plate likely helps absorb the camera-end of the impact too. 




#390499 one Inon Z240 producing less light

Posted by Undertow on 23 December 2017 - 04:55 PM

Inons have 2 flash tubes. Perhaps one has blown.