Profoto Acute 2 vs Acute Acute 2R

Discussion in 'Lighting Equipment' started by thomasbeaman, Sep 23, 2007.

  1. So I have finally decided to make a lighting upgrade. I am going with the
    Profoto Acute 2 system. I recently read something from a user who recommended
    not getting the new R version with the built in slave becasue he said if that
    little gizmo breaks, you need to send the entire unit in to be fixed. But with
    the regular Acute 2 version you would only need to send in the slave piece. My
    questions is to all the Profoto users. Which do you recommend if you were
    buying one of the 2 systems right now. And I know that there are other systems
    out there but I have decided to go with one of these so please keep your
    suggestions to the acute 2 or the acute 2r....thanks so much.
  2. Sorry for the typo in the title
  3. I'd get the Acute 2R. I've used various LPA Design Pocketwizard remote triggering systems ( they make the receiver in the 2R pack) for about 10 years now, and except for the time a stage hand plugged the sync cord from a receiver into a live electrical circuit instead of the strobe he was supposed to plug it into I've had zero troubles with them.
  4. Thanks alot Ellis. I appreciate the fast response
  5. I'm in the same boat as you are. Acute vs Acute 2R. I was told via a seller that if the antenna does break it (antenna) can be bought and shipped with out having to ship the power pack to the repair clinic. I was told the above from an ebay seller who was selling an acute 2R with heads a few weeks ago. He said he bought the antenna new (as his broke...) from the "Camera Clinic" in NY. I'd call your local Sammy's camera dealer to see what they say as confirmation.
  6. Flash Clinic not Camera Clinic...
  7. the external antenna is very much a user replacable part -- it just screws on and off. depending on the physical circumstances it is always necessary for the system to work. The D4 has the antenna contained with in the pack. The biggest flaw I see in either an Acute 2 or the Acute2R is the very long t0.1 flash duration at full power with the standard Acute2/D4 head: 1/70th second according to my tests. t0.1 is the flash duration you want to know if you are interested in two things:

    1.) the ability of the flash to stop motion at a specific power setting.

    2.) It dictates the shortest shutter speed you'll need to set the camera to in order to get full light output to the film or sensor. With a t0.1 flash duration of 1/70th second at full power, you'll needto set the camera to 1/60th of a second (maybe 1/80th). Anything shorter than that (like 1/125th) will clip the flash exposure.

    How much either of these things will bother you is up to you.

    In the Profoto line I much prefer the (more expensive) D4 and Pro7A.
  8. BTW, Ellis, any idea when / where we'll be able to enjoy the full fruits of your recent light-
    testing labors? :)

    Looking forward to it!
  9. Ellis,
    I had no idea of this. So am I understanding it correctly? If I shoot with an Acute 2 system at full power....I can't shoot faster than 1/60th? If I am understanding it right, I might be rethinking my purchase. Please let me know if I have that right
  10. I just checked with Profoto's site and they claim that the flash duration is 1/320 sec @ max power. But Ellis tested it at 1/70th of a second. How can a huge company like Profoto get away with bumping the numbers like that? Now I am back to square one on picking a system. The Acute 2r sounded perfect but if the full power flash duration is 1/70th or a second, that is just not acceptable for something that is so expensive.......ok...back to the drawing board
  11. Thomas, I have to assume that is a t0.5 flash duration range not t0.1
    the t0.5 flash duration measurement standard is used by virtually all manufacturers. It measures the duration of the flash when the output level is above 50% of maximum output. The t0.1 standard measures the flash duration when it is above 10% of the maximum output.
    Here is Broncolor's explanation:
    Flash Duration
    The duration of a flash discharge defines the ability of the flash system to capture or 'freeze' a moving subject, and there's a long standing debate continuing as to how it should be measured. The problem is that the intensity of light given off by a xenon flash tube isn't constant through the duration of the discharge. When a fully charged capacitor starts to supply energy to the tube, the light output rises to a maximum very quickly indeed. As the capacitors start to discharge, the light output starts to fall, quickly to start off with, then more slowly as the energy is finally exhausted. In theory, the total flash duration should cover the entire period between the flash being triggered and the total extinction of the tube. Because of the shape of the flash curve - rapid rise, rapid fall, then a slow discharge at the end or 'tail' of the curve, it isn't practical to use this total time, especially as the light energy at the tail of the curve has little practical effect on exposure. Instead, manufacturers who follow ISO and DIN standards use the t=0.5 standard, which defines the duration of the flash to be the time during which the flash intensity exceeds 50% of its peak value. This gives a good basis for comparison between different manufacturer's units, and most studio flash units have t=0.5 durations of between 1/250 and 1/2,000 second.
    The t=0.1 definition, which defines flash duration as the time during which the intensity exceeds 10% of its peak value. Generally, the t=0.1 flash duration is about three times as long as the t=0.5 value, and this can be used as a reliable guide to the motion stopping ability of a flash unit.

    Bron glossary
    So am I understanding it correctly? If I shoot with an Acute 2 system at full power....I can't shoot faster than 1/60th? No that isn't correct. You can shoot faster at speeds faster than 1/60th but syncing at shorter shutter speeds may not get you quite as much light on the subject as you were expecting. I haven't measure the difference in exposure --it may be a 1/3rd of a stop (or less or more).
    I don't consider this to be a deal killer on the Profoto Acute2R 2400 system -- there is too much to recommend them: the light quality, the built in Pocketwizard receiver, the range of output ( the reflector/speedring attachment system, Profotos range of light modifiers, the choice of symmetric or a asymmetric power distribution, the bivoltage option, etc. But that long flash duration is definitely something I would take it into consideration as something to be aware of if you are at full power on the 2400 watt-second Acutes with the standard head and photographing subjects that are moving a lot and you really want to freeze their motion.
    I hope that clarifies things for you.
  12. Yes....yes it does. Thank you very much for your valuable information. I really appreciate it
  13. BTW: the t0.1 flash duration measurement was made using a Broncolor FCC meter.
  14. I bought 2400R used from B and H...receiver is busted and now it is a huge headache. It arrived broken but part is attached to main board, main board is super expensive, sending it back is international etc etc...a real pain.

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