34 minutes ago, Pavel Kolpakov said:In nearest months we are waiting for the sample of YS-D3 MarkII from Sea&Sea, for tests. Hope the TTL control has become better there. So, the nearest future will show.
I'll be interested to see if you find the same discontinuity in the TTL response curve that I'm seeing.
I'm using Cree C503B red LED, driven at max current. 40us preflash trigger pulse, ~50ms between preflash and main flash, and then variable-length main flash trigger pulse.
- 13us = ~GN2.8 smoothly up to 60us = ~GN5.6. (output flash pulse 36us...70us)
- Then between 60-70us it jumps directly up to GN8+0.5EV. There is no input pulse length which generates an output flash pulse length between 70-160us.
- Above that it's a smooth curve from GN8+0.5EV up to GN22 at 1000us and GN22+0.3EV at 1600us. (output flash pulse 160...1400us)
Unfortunately, GN5.6 - GN8+0.5EV is kind of a big gap, right in the range where TTL exposures are likely to fall.
I don't know if that's something they can fix with another firmware update.
Why do strobe manufacturers not simply have a straight linear profile for us LED-based trigger board folks? Something like:
- 100us input pulse = GN2.8
- 150us = GN4
- 200us = GN5.6
- 250us = GN8
- 300us = GN11
- 350us = GN16
- 400us = GN22
- 450us = GN32
That would be really easy for us to generate, and would allow plenty of accuracy on the strobes themselves (much more so than the exponential lengths they try to capture now, which are really short for low power and really long for high power). And it's not like the strobes don't already have different profiles built into them for number and timing of preflash pulses; this would just be one more profile.
If we standardize on that profile, then ANY strobe would work with ANY trigger board. No need for us to profile them every time a new strobe comes out. That'd be good for the strobe manufacturers too; more potential customers for their new strobes without needing to wait for us TTL board folks to profile them.
