Jump to content


Tom_Kline

Member Since 07 Nov 2004
Offline Last Active Jul 18 2019 06:01 PM
*****

#407231 Snoot aiming advice - Retra LSD

Posted by Tom_Kline on 17 June 2019 - 05:13 PM

Alex M was able to make it work here: http://wetpixel.com/...lsd-prime-snoot

 

Do you have an older Z240 with a bulb rather than an LED?

see this: http://wetpixel.com/...showtopic=51586

 

See what Oskar says in post 10: http://wetpixel.com/...showtopic=62595

 

An idea: swap your 2 Z240s so the one on the camera is now the slave. Maybe the other one lines up better????




#405045 A7SIII, Lens/port recommendations

Posted by Tom_Kline on 07 April 2019 - 11:46 AM

Thanks for the mention Chris.

I have been shooting salmon UW for several decades and with digital for about 1.5 decades. I have posted some of my technique shots here on WP. Basically I am using a DSLR for digital. I started with APSC (Nikon DX) then added Canon full frame as it came out first. My most used lens for salmon with the Nikon was the 10.5mm fisheye and with the Canon the 8-15mm fisheye zoom (I got one within a week of it being available!). I have only a few salmon shots done without remote control, which is of the simple 3-wire release type. I use flash for a good portion of my shots. It is very dark here (sun less than 10 degrees above horizon at true noon and it is behind a mountain) when the Coho spawn. On the plus side water gets very clear once the air is at sub-freezing temperatures!

 

Lots of examples on my website. The few vids I have done show shots being taken:

https://www.salmonog...lleries/Videos/




#403343 Sea and Sea internal Correction Lens

Posted by Tom_Kline on 08 February 2019 - 03:34 PM

I would not use either of my 16-35mm lenses without it. Yes!




#400609 Who shares on Instagram?

Posted by Tom_Kline on 07 November 2018 - 06:45 PM

OK folks, am I missing something here? I take great care in how I compose my images, but Instagram "insists" on cropping the image... doesn't it? I have nothing against square, but if I wanted a square image, I'd take it that way...

 

Not to mention the ridiculous workflow to put an image up there from a laptop.

 

Help out a skeptic will ya? ;-)

 

Based on my recent experience it is best to post square images. Recompose them yourself or you may see undesirable results. If one clicks on an image one will see the image without cropping but this requires a bit of effort (lots of clicking). It is much easier to scope out what is there by looking at pix in the default grid.

 

I am using the Lightroom app mentioned back a bit in this thread. No major issues with workflow. However, one needs to delete an image and then undo the deletion and re-upload to see edits. Not quite as smooth as other LR apps.




#400390 Canon vs Nikon for underwater photography

Posted by Tom_Kline on 28 October 2018 - 10:06 AM

I use both systems. The main reason being historical. Nikon had the early advantage because of the Nikonos line and its legacy. The standard bulkhead is still Nikonos. It (the final iteration) was designed for film TLL. UW strobes also came with TTL that worked directly on Nikon film cameras. Canon preceded Nikon with full frame (FF), 24x36mm, sized sensors. The first 2 models were very expensive (US 8K each), then the 5D came out... Finally Nikon came out with FF for their 3rd generation dSLRs, the D3 series.

 

As well there have been differences in their lens lineups important for UW. Nikon had an APSC fisheye lens (10.5mm) whereas Canon did not, not even an APSH one. Finally, they came out with their 8-15mm that provides a fisheye for all 3 formats (FF, APSC and APSH). It has only been in the last few years that Nikon came out with an 8-15mm. While their 16mm fisheye lens is good (I have one), it does not focus as close as is needed for some UW applications. Canon is deficient in the 60mm macro department. Their 60mm is only for APSC. If one wants to use a modified Nikonos RS lens one needs to use a Nikon body.

 

There are pros and cons to both systems. It is nice to have some topside capability too. Canon makes two AF pancakes, a 24mm and a 40mm, that I take along with a 100-400mm zoom and a 7D2 for travel that I use alongside a Canon FF body for UW. If I travel with a Nikon (to use a Nikonos RS lens) I do not want bring the 7D2 since the lenses are not interchangeable. So on my last trip I brought along a second D3X body for topside shots (maybe not the best for this).  I plan on using a Z6 for this in the future. However, Nikon does not make any pancake AF lenses. Pancake lenses are good when one is space limited.

 

I use FF for UW because of high ISO ability for shooting in home waters, Alaska, where it is darker than in the tropics. I use the big bodies because of the big batteries because of the cold temperatures. Your needs may be different.

 

Now that things are moving mirrorless.....




#399507 Strobe arms

Posted by Tom_Kline on 20 September 2018 - 09:33 PM

Here is a good beginner tutorial:

https://reefphoto.co...-arms-do-i-need




#398982 Blackwater dives and filming

Posted by Tom_Kline on 03 September 2018 - 01:34 PM

The way blackwater dives are done at Kona, Hawaii there are no lights other than the ones held by the divers and a deck light used for gearing up (this may get turned off when everyone is in the water but the captain). Lights are used, however, for other blackwater operations - maybe the top source of light in some of the vids linked above.

 

Diver held lights are enough to attract squid and dolphins feeding on the squid on some dives from my experience. Potentially sharks too but I have yet to see one. I have seen vids being done on a few of the bw dives I have been on in Kona - the lights were attached to brackets in the usual way, e.g. Ultralight arms and trays. I have also seen a Gopro used with lighting provided by a handheld light (bright one provided by the boat - which I always refuse as all mine are attached to the housing but I am only doing stills).




#398748 Nikon Mirrorless cameras - Z6 and Z7

Posted by Tom_Kline on 27 August 2018 - 11:47 AM

The FTZ does NOT support screw-drive type AF. It might be possible for someone to develop one that does, either Nikon or a 3rd party. However, it might turn out that the communications protocols in the new Z cameras will not allow this, e.g., adapted lens AF is too slow (such as changing focusing direction).

 

But..... there is another alternative that seems more interesting to me. That would be to develop an RSTZ adapter for manual-focusing-only with Nikonos RS lenses like done on the RS camera bodies. This would require an adapter with a the screw drive in it but instead of communicating with the Z camera body, it would communicate with an RS analog control switch on the housing (e.g., with a cable)!!! If I recall correctly the RS manual focusing switch controlled focusing speed as well as direction. Therefore a functional analog (to the RS) would be preferred. This hypothetical RSTZ adapter would obviously have to be paired with a housing that came with this switch.




#397304 Need advice on Fisheye / Wide angle lens for D850

Posted by Tom_Kline on 11 July 2018 - 07:56 PM

I just bought the zen 230mm for the 16-35, and I am in the same crossroads as you are, dont know if It is a better choice sigma 15 or nikon 8-15. I know the sigma doesnt need anything extra, but the 8-15 needs a zoom gear on my nauticam. If I get the 8-15 will the shades of the 230mm dome show up in 8mm?? Do I need to get the 100mm dome for it?

 

Yes, the shade will be seen in 8mm pix. At 8mm the angle of view is almost 180 degrees all the way around the image and not just at the diagonals as at 15mm. Find out if the shade can be removed - many can.




#397265 Need advice on Fisheye / Wide angle lens for D850

Posted by Tom_Kline on 10 July 2018 - 11:15 PM

Tim! I appreciate your reply and honesty... I have been spending so much time trying to justify the costs of everything that I was making the wrong decisions. 

 

Today I ordered the ZEN 230 Glass Port for the 16-35 and bit the bullet... Not point in doing it wrong right?  Your reply came after I ordered it (and after a bottle of wine) so that helps me feel better about the decision... 

 

Next I need to figure out what Dome to get for the 8-15 but that is less of a rush for me.

 

Cheers!

 

H

You can use a large dome with the 8-15 fisheye. In fact the results will be better than with a smaller dome. Even with just 12 Mp and the smaller DX format I got better results (as in sharp all the way to the edges of the frame) with a superdome compared to all the smaller ones.

Tom

 

Watch this video:

 

http://wetpixel.com/...thout-the-drone




#397002 Need advice on Fisheye / Wide angle lens for D850

Posted by Tom_Kline on 03 July 2018 - 05:03 PM

Read this: http://wetpixel.com/...by-jack-connick




#395169 Wetpixel's Nikon FX wide-angle lens review

Posted by Tom_Kline on 07 May 2018 - 10:26 AM

The distance to the dome I was referring to is the subject to dome distance. The virtual image surface shape is a function of focused distance, only spherical at infinity. This is probably why small domes work for macro subjects where the dome is very close to the subject so the virtual image is flatter. Note that this thread is > 3 years old whereas FE question is new.

And for a subject at infinity the virtual images lies at a point which is 4 x the radius of the dome from the centre of the dome which is where the principal point of the lens should be positioned. This means that the centre of the mage is at 4R but because the virtual image is spherical, depending on the lens's angle of view, the edge of the image will be somewhere closer - exactly where will depend on its position and the dome's radius (radii) and thickness and refractive index - its complicated. But the camera lens is not much of a factor here because it can only image what it 'sees'. Its ability to do so will be dictated by the virtual image produced by the dome port and subject and any inconsistencies of the camera lens such as field curvature at closer focus. Its all a bit messy.

 

The 'less curved' dome idea is in effect the suggestion of positioning the camera lens closer towards the dome as opposed to ensuring it is aligned at the centre of the dome. You may want to try doing just this (should be easy enough). If I remember correctly, I think that you will find that it results in the trade off of reducing the field of view as opposed to doing what your diagram illustrates so is counter productive.

 

Sadly I suspect the 'filmdays' rule of thumb of 90 degrees being the maximum viably/easily correctable field of view still applies with dome ports though bigger does help .....

 

I still disagree about the unpredictability of lens performance underwater behind dome ports. Its lack of technical information which hampers prediction nothing else.




#394465 Post Processing Software Advice

Posted by Tom_Kline on 16 April 2018 - 01:34 PM

I too am a long time LR user, since version one. I do not think there are any other programs currently doing digital asset management (DAM) to the degree that LR does. I probably spend more time doing DAM work than post-processing; entering keywords, titles, captions etc. This may not be important in the beginning but once you have a large number of images, e.g. I have about 1/2 million images in my LR library, it is indispensable. It is a very good idea to work on DAM from the beginning!

 

Do you know about Creative Live?  https://www.creativelive.com/

They are currently doing a LR boot camp. The basic stuff was last week. There are 3 weeks to go including this week that are more advanced but there is some re-capping of earlier material as well. It might be well worth your time, about an hour or so each work day to watch these. Each day's lesson gets repeated until the start of next day's lesson to accommodate time zones around the planet. It is free during the live broadcast (next three weeks). The previous week's material is presented again on the weekend.

 

I have been watching it and have learned new stuff even though I am an old hack at it. For example, I did not know about customizing the bottoms of the side panels - I now have my logo there. I do not agree 100% with the way the presenter, Ben Willmore, uses LR, such as how he sets up his folders. This is largely due to some of the peculiarities of the way I work. Nevertheless it is a very useful class to watch and learn new stuff.




#391775 Ambient Backscatter

Posted by Tom_Kline on 27 January 2018 - 03:48 PM

I have the same problem as well when shooting salmon in streams using ambient light. There is a fair amount of drifting debris. Bubbles can be a problem (as just suggested) as well. Shooting with a fisheye lens at point blank range helps to minimize the problem. As well, it is best to avoid shooting into the light. Sometimes one does not much of a choice other than not shooting at all.

Check out this shot:

 

http://www.salmonogr...mon/i-9CHRBCD/A

 

(easier for me to find image on my site). Note the light blotches in the water column. I see a dark one too (left side), probably a twig. Not too bad backscatterwise at the spawners that were real close. I angled the camera to avoid shooting into the sun - this gave the reverse perspective from many of my other shots - but easy to see the eggs emerging from the female from this angle! A downside is that the housing cast a shadow on the bottom (shot taken less than 2 hours from true noon).




#390538 RETRA Strobe Thread

Posted by Tom_Kline on 26 December 2017 - 09:58 AM

I wonder if the FIX / upgrade to solve the TTL issue on the UWT circuitry be an easy fix?

 

 

The RETRA strobes will not be able to do any sort of wired TTL.  There are just TWO contacts in the wired bulkhead. They are for basic flash synchronization, nothing more. There is thus no Nikonos film style TTL as found in older strobes. Therefore the various converters for using Nikonos TTL will NOT give you TTL!!!