Jump to content


rtrski

Member Since 13 Jul 2007
Offline Last Active Jun 17 2014 03:36 AM
-----

Posts I've Made

In Topic: Ikelite housings: fiber optical or electrical?

25 May 2014 - 05:44 PM

Several DIYers have come up with very small LED "flash" units that do fit the Ike housing bump atop the hotshoe instead of the sync cable to the internal TTL electronics and allow FO coupling right thru the housing wall, to fire Inon or other strobes (even Ike's w/ the FOadapter), but there's a catch... they only permit manual sync. A circuit that does full TTL communication with the camera and can fire and quench LEDs at the speed to be preflash etc for a TTL strobe to mimic is nowhere near as simple.

 

I did one but figured out pretty quickly that I wasn't buying anything over a sync cord than eliminating the watersealed electrical connex. Until Ikelite strobes support optically-coupled TTL mimickry, I don't see them adding the bump space. It just makes the next request "remove the TTL electronics from the housing...and cut the price" and helps sell other strobes like Inon.  


In Topic: Scaling back gear for topside/diving mixed trip (Hawaii)

19 May 2014 - 10:03 AM

Well, we're in the final packing phase for departure.  Since initially posting I've sold my 150-500mm and the 1.4x TC, so no temptation to bring those.  I did get some good nebula shots using a 180mm with the iOptron rig, as well as some nice test Milky Way wide-angle shots with the 15mm fish, so both will definitely be coming...that was fun.  I've also realized we'll be on the ground in time to set up the camera on a tripod for the night of 23 May and the possible new meteor shower. 

 

I also finished a 2nd generation 3d print of my ring flash adaptor for my DS51 and in tests it looks like it provides pretty good light down to f20 at ISO400, up close...  So...looks right now like I'm going to take a chance and leave the z240's home, plus most of the arm components.  I'll still bring the 8-16mm and minidome for it in case I think I might want to go for some natural light wide-angle a dive or two, but mostly focus on macro with the 105mm and the ring assembly.  That gives me the room for much of the other gear (but not all).

 

Wife might find a couple items in her dive bag, but hopefully I will not spill over into 2 camera backpack carry-ons.


In Topic: Focusing during a night dive with red floodlight

18 May 2014 - 05:28 AM

Please post back if you find a solution you like for other Olympus users.  I'm not sure my Sony-based rough ideas were really that helpful.


In Topic: Focusing during a night dive with red floodlight

16 May 2014 - 03:31 AM

I'm assuming you're dealing with an electronic viewfinder.  Are their any viewfinder brightness or contrast or RGB level options you can adjust for night dives?  Does the camera support any focus peaking type highlighting options you could set for a different color (white, yellow) so it would show up in contrast to the red ambient view and thus at least help you see the outlines of what's presently focus locked?

 

I have a sort of similar issue with the Sony SLT-A55.  The original SLTs (A-33, A-55) always try to give a what-you-see-is-what-you-get view related to your settings, which means that if the camera doesn't know strobes are present (manual synced, not TTL-connected) the viewfinder helpfully goes "black" with settings like ISO400, f8, 1/160th in dim underwater conditions, although the AF boxes still light up green because the AF module has plenty of light to focus lock.  My only solution was to go to a TTL connection or like you are experimenting with provide a butt-ton of focus light.  That much focus light of course scares off critters and is still less than a strobe so I'd barely see what I was trying to frame...the TTL is the more usable option for me.  (Newer Sony SLTs have a menu option to disable this 'setting effect' on the electronic viewfinder so the view always mimics ambient levels instead of the setting levels.)


In Topic: 3D printing gear for Olympus 12-50mm lens, need input

16 May 2014 - 03:21 AM

I haven't looked at the thicknesses of that part in any detail, but most home-level machines (Makerbot, Solidoodle, etc) using the FFF method (Filament fusion fabrication) tend to an out-of-the-box tolerance of 0.3mm per layer in the vertical axis with tighter positional tolerance available in the XY plane and use a 1.75mm filament input thru a 0.35mm nozzle.  So the supplier might just be covering their bases a bit quoting a 0.5mm tolerance.

 

Cutting the tolerance to 0.1mm will mean a much longer print time, and potentially more warpage or weaker layer bonds on long prints although the surface finish will be cleaner.  Really for a zoom gear that isn't very 'structural' I'd think the 0.5mm would be good enough, assuming the part design had some wiggle room for the meshing gears.

 

I think the person who designed that posted it here too, you might ask him his thoughts ... do a search on the DIY/Unrequited Gear Lust page and it should turn up.