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ChrisRoss

Member Since 13 Feb 2016
Offline Last Active Yesterday, 07:48 PM
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Posts I've Made

In Topic: Manual and TTL

Yesterday, 07:00 AM

That may be the case but the end result is the same. 


In Topic: Manual and TTL

Yesterday, 02:05 AM

Your style of shooting sounds similar to what I do.  Running two INON Z-240, camera on f8 I just try to get about the same difference from everything sometimes a little low on flash sometimes a little high and adjust it in RAW later if needed..

 

I really don't follow what you are doing with your tests.  The YS-03 is TTL only and ST-100 I don't know how it performs, but your test indicates it is underpowered.

 

As to what to do, you can't go wrong with better quality flashes.  If you get INONs or Retra or similar you can run them in either TTL or manual.  TTL will work directly with the onboard flash of the RX100 or you dial the onboard flash compensation down and use them in manual.  The A7R-II  of course does not have a built in flash and you need a trigger to do TTL, but believe you can do wired manual.  TTL is more hit and miss in general on wide angle and the success or otherwise depends upon the cameras internal TTL system as much as anything else.

 

On your macro question, just increase the aperture, the flashes should be able to do ISO100 af f16-22 (on the full frame A7)  You don't want to get down to such small apertures on the RX100.  But it's really not a problem unless you want a black background,  I'll shoot at f8 ISO400 on my m43 system and the BG colour goes to blue/green depending on what water you are in  and I don't mind that effect.  If you want to darken the BG, fix the ISO at minimum on the RX100, you could float it up a bit on the A7 as you are stopped down more and flash will recycle faster.


In Topic: Group Cluster Focus Points - Macro on Nikno

12 December 2018 - 09:57 PM

If you read the description GRP tends to go to the closest subject among the 4 sensors, but it will also be the one with most  contrast.  You have no control over what it picks and it may pick the wrong thing. 
 
The DOF is what it is regardless and all you do is pick what to focus on.   DOF at macro focal lengths is said to evenly distribute in front of and behind the focal point, so focusing on the front of your subject wastes DOF.  So best approach is to focus on the middle of the subject to give best chance of getting the DOF to fall in the right spot.  To do that you really need to use a single focus point.

In Topic: YS-D2 paired with YS-03 & YS-01 with YS-03

09 December 2018 - 10:24 PM

The problem is that what the TTL system calculates in an pulse length and it will be an average between the two flashes.  It puts out a pulse to measure and each flash will mimic the duration.  But there's no escaping the fact that the there is a two stop difference between the two strobes, how much of that difference is due to "size" of the tube and how much is different durations is unknown, but is likely mostly size or power of the tube. 

 

What you could do is put the widest diffuser on the D2J and leave the YS-03 bare and that should make their output about equal.  The wide diffuser on the D2J costs 2 f stops.   Or if you want them both diffused  use the 2 stop diffuser on the D2J I'm guessing the standard diffuser on the YS-03 is about 1 stop or so which gives you a 1 stop difference which could be more manageable.   You could try it out on land to see how they respond.


In Topic: Nauticam Vacuum Valve II

09 December 2018 - 06:35 AM

Get the vacuum valve, the green light gives great peace of mind.  On the subject of depth, O-rings are dynamic seals and need to be loaded to seal properly.  Loading the o-ring occurs due to the pressure difference across the o-ring.  As you get deeper the seating force on the o-ring goes up and the seal is better as the o-ring is being pressed harder against the o-ring groove.  Eventually the force will be high enough to break the o-ring but not at any depth you will ever dive to and which the housing will survive.  This is also why you lube the o-ring, so it can slide in the groove as it is pressured and press against the housing surfaces to form a seal

 

This is why floods are more likely in the rinse tank, bump the housing a bit and the parts may move enough to break the seal.  Now if you have it under vacuum you can't physically open the back or remove a port.  The O-rings are preloaded and sealing properly on the surface.

 

As to M14 or M16, look at the housing and see where it's likely to be easily accessed if for example you have all your flash arms attached.  Or is you need the M16 for a cable bulkhead for example  use the M14.