Hypersync Pocketwizard MiniTT1 & FlexTT5 on Studio Lights?

[ellis_vener_photography]

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<p><em>Ellis - on flash duration how do I find out what the slowest flash duration is on the Bowens / Calumet 750R monolight?</em></p>

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<p>Most likely the longest flash duration will be at the lowest power setting. However this will also mean you won't have a lot of light to work with once you go above your camera's x-sync shutter speed as the hyper speed sync feature of the only uses a slice out of what is now a smaller pie.</p>

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<p><em>Also the specs on your Profoto Acute2 2400 power pack is rated at 1/320 sec @ max power. How are you getting the 1/70 sec? </em></p>

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<p>I measured it with a Broncolor FCC meter to pin down why I was getting so much motion blur with the Acute 2 2400 at 2400 w-s with a single head.</p>

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<p><em>To get the t.1 don't you divide the t.5 number by 3? In your case I think it would give you 1/107 sec correct?</em></p>

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<p>Here's where it gets interesting: how were the measurements made? What tools were used to measure the flash duration with? Both Profoto and I could both be right yet using different tools. Rob Galbraith, Paul C. Buff, and myself have had a three way conversation about differences in photo receptor sensitivities used for measuring flash duration. In any case there is not a lot of difference between 1/107 and 1/70th second flash duration -- both are really long for flash duration.</p>

[ellis_vener_photography]

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<p>With my Bowens/Calumet 750R monolight, the fastest flash duration is a slow 1/650 sec at full power. </p>

 

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<p>Are you sure about that? if you are just going by the specs it could actually be the reverse. </p>

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<p>Ellis, I guess I don't understand this post as you say above that the ProPhoto was at 1/70th of a second whereas reading the quote, one would expect it to be 1/300th or even 1/500th or faster.</p>

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<p>Even Profoto says that according to their measurements, at full powe wit ha single head, the Acute 2 2400 w-s pack t0.1 is around 1/100 ( they list the t0.5 for that set up as 1/320th @ http://www.profoto.com/products/generators/acute/acute2-2400</p>

[rob_h5]

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<p>With my Bowens/Calumet 750R monolight, the fastest flash duration is a slow 1/650 sec at full power.<br>

Are you sure about that? if you are just going by the specs it could actually be the reverse.</p>

<p>Most likely the longest flash duration will be at the lowest power setting. However this will also mean you won't have a lot of light to work with once you go above your camera's x-sync shutter speed as the hyper speed sync feature of the only uses a slice out of what is now a smaller pie.</p>

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<p>Ellis, thanks for answering all my questions. As with fastest flash duration unfortunately 1/650 <em>is the fastest duration </em>@ full power for the Bowens/Calumet 750R. I wish I were wrong but Bowens only lists the fastest duration at full power for their monolights. As I mentioned before there are other models the monolights go as high as 1/2300 sec or higher flash duration @ max power.</p>

<p>Peter I think you stumbled upon the mystery as to why hypersync works with some studio lights and not with others which has to do with the electronics of the studio light. Basically you and I need a studio light (monolight or power pack) that has a slow flash duration at max power like Ellis's Profoto studio lights. It may work better in low light or total darkness with the hypersync but at that point you might as well sync at regular camera speeds and just use the flash at the fastest duration at max power with these certain monolights another trick used in high speed flash photography. My Bowens lights has a slow flash duration only at the lowest power setting. As Ellis mentioned with this trick since you are only getting "a slice of the pie" and because you are using the flash as a continuous light source you need a studio light with a <em>slow flash duration and at maximum power.</em></p>

<p> </p>

[rob_h5]

<p><strong> </strong><br>

Peter - which Dynalite model do you have? The flash duration listed on the new Dynalite monolights is actually shorter as you power down much like the Profotos. But the slowest flash duration is at still only 1/675 sec. I don't know if its a slow enough flash duration though to use the PW hypersync trick.</p>

<p>Dynalite Uni400JR<br>

1/675 sec @ Full Power<br />1/1100 sec @ 1/2 Power:<br />1/1800 sec @ 1/4 Power-<br />1/2200 sec @ 1/8 Power AC<br>

<strong> </strong></p>

[peter_poremba]

<p>For the fast flash duration it was a M2000wi set at 250ws with a custom 4040 studio head that is fitted with a bi-tube from the sport head. That flash duration is around 1/6000 t.5. For the slow duration I used a new MP1600 with the switches set at 1600 and the variator set at the lowest (lowest voltage) with a extra head cable. That duration should be very close to the Profoto Acute24 if not slower.</p>

[rob_h5]

<p>Peter - I wasn't sure which studio light you were using, monolight or studio pack. The Dynalite MP1600 studio pack is a brand new model and I couldn't find any flash duration specs on it because its a new studio light. But I agree you should get very slow flash durations @ max power close to the Profoto Acute24. Since I use Bowens lights, I am unable to perform this hypersync trick very well at least outdoors in daylight since my slow slowest durations are at min power. I believe I am out of luck but I will test it. Let us know how your results turn out with your new Dynalite studio packs. Also another note about color balance since you are using only part of the flash you have to time the flash with the PW Hypersync at its zenith or reach their peak of flash illumination to get the proper color balance, sort of like the old school slow burn flash bulbs and delayed syncs ( M,S, F syncs) found on the old-school cameras!</p>

[peter_poremba]

<p>Ok, I did some more testing with my Nikon D7000 and the Pocketwizard MiniTTl. First I was able to measure the flash duration of the Dynalite MP1600 with the variator turned all the way down to get the slowest flash duration. To make it even slower I added a 35' cable to the SH2000 Studio Head. The end result was 1/220 using t .5. I needed to add a lot of delay to the Mini (currently set at 900) but I'm getting a very clean 1/500th. It appears the output did not go down as I expected. I made one exposure at f5.6 1/250 and then another at f4.0 1/500th and the one at f4.0 looks overexposed. I'm going to repeat the tests tomorrow and see if I can push it a little further. Color looked the same but I need to double check the settings on the camera.</p>