É, eu estava vendo isso. Quanto mais você aumenta a velocidade do sincronismo, mesmo com flashes que suportam HSS, você necessariamente vai ter perda de luz.E é somente com coma a função TTL que você consegue sincronismos mais altos...Eu queria muito usar o flash no Manual, mas parece que HSS com pocket wizards só com a função TTL ativada.
Mas Léo, em relação a questão do ISO, se a minha intenção fosse a de "matar" a luz ambiente em relação ao objeto sujeito ao luz do flash, a seleção do ISO em 50 com Sync de 1/200 teria o mesmo resultado da Nikon D200 com Sync de 1/250? Já que a abertura do obturador somente influi na exposição de flash, certo? Poderia "matar" a luz ambiente brincando com o shutter speeed e com o ISO??
Paralelo a esse assunto, eu estava lendo um texto muito interessante de um funcionário da Pocket Wizard no Flickr e ele fala dessa limitação na 5D MKII com High Sync acim de 1/200, mas acredito que elas valem para todos as DSLR com obturadores mecânicos, inclusive Nikon:
Fonte:
http://74.125.47.132/search?q=cache:JNVXh4h4RrUJ:www.flickr.com/groups/pocketwizards/discuss/72157616249374057/+5d+Mkii+FLASH+SYNC+POCKET+WIZARDS&cd=1&hl=pt-BR&ct=clnk&gl=br will try to be clear.
The ControlTL radios have 2 modes of remote flash operation:
HyperSync *or* High Speed Sync (FP Flash)
HyperSync works with either a Mini or Flex on the camera and any PocketWizard Receiver, including the Plus II. HyperSync moves the trigger timing around to try to achieve faster shutter speeds with manual flashes. Its drawbacks are that you must have a manual flash capable of longer flash durations to make light for the entire exposure. Not every flash/camera combo can do this and maintain even exposure across the frame.
HSS only works via PocketWizards if you have a Mini/Flex on the camera AND Flexes as remotes. HSS does not work with the Plus II or any other PW receiver except the Flex. The remote flash *must* be a Canon Speedlite from the compatible list and have HSS capability. The camera must be a compatible Canon camera. HSS happens when the camera tells the flash to use a special light emitting mode that makes continuous light for just long enough to light the entire exposure at faster shutter speeds. Its drawbacks are much reduced light output at faster shutter speeds.
If you want more light than HSS can give you, then HyperSync is your only option. It allows you to try your more powerful manual flashes at faster shutter speeds. If you want guaranteed even lighting across the frame for every shutter speed and your manual flash/camera combo can't do it, then you need Canon flashes and HSS and you have to deal with the loss of light.
HyperSync is not guaranteed to work at every shutter speed all the way up to 1/8000 with just any remote flash and any camera. It is something you *try* and something you *tweak* to see what works with *your* equipment. Once you have it dialed in, it will continue to work.
Faster manual hot shoe flashes like the Vivitar 285HV are not going to be great at it. You might get something usable at 1/8000, but maybe not at 1/1000 - it depends on how fast your shutter is and how long the flash duration is. You need longer flash durations like you typically find in slower studio packs for HyperSync to work at all shutter speeds. Longer flash durations often occur at the higher flash power settings, but not always. Even then you might get brightness changes across the frame. You might get color shifts across the frame. This is not the fault of the PocketWizards - it is just the result of pushing flashes and shutters to their maximum capacity.
The 430EX *can* do HSS *if* you have it on a Flex as a remote with a Mini on the camera. It is a Canon Speedlite with HSS powers so the Flex can tell it to do that. The ControlTL system does not give your manual flash powers it does not have. The Vivitar285HV does not do High Speed Sync (FP Flash). You can only try HyperSync with it.
The SB600 is nothing more than a fast manual flash in this setup because it is not a CANON Speedlite *and* you are not using a Flex as a receiver. So it is just like the Vivitar 285HV. You can try HyperSync with it, but you can't do HSS with it for a Canon camera at this time.
The 430EX in *manual* mode is also identical to the Vivitar and Nikon hot shoe flashes in this regard.
I am always working on better ways to explain this. I'm sorry I can't seem to answer it clearly for everyone all the time.
Patrick from PocketWizard
Abraços,
Rodrigo