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Problem with freezing.

Guy Mancuso

Administrator, Instructor
In the menu do you have it set for leaf shutter. I don't have a DF to look at the settings but there is a setting for this. Look for the PDF of menu items on the DF
 
This is weird, because even at 250/th of a second there shouldn't be that much motion... with or without the lights... are you shooting with lots of lights in the studio?
Is the model moving fast in the photo you shot? It would seem like something other than the lights if you have two packs and they are both doing the same thing.
Can you show us the full image (not 100 percent cropped)
 

geronimo13

New member
This is weird, because even at 250/th of a second there shouldn't be that much motion... with or without the lights... are you shooting with lots of lights in the studio?
Is the model moving fast in the photo you shot? It would seem like something other than the lights if you have two packs and they are both doing the same thing.
Can you show us the full image (not 100 percent cropped)
In studio the shutter speed doesnt freeze the movement.

She is sprinting but starting about 2-3 meters before the shot so she is not really getting any momentum.

https://dl.dropbox.com/u/35705091/blur.jpg
 

xinchenc

New member
In studio the shutter speed doesnt freeze the movement.

She is sprinting but starting about 2-3 meters before the shot so she is not really getting any momentum.

https://dl.dropbox.com/u/35705091/blur.jpg

Considering your shooting condition: no modeling light, no ambi-light in the studio, which means a dark condition, that non-freezing problem in just because of the ability of the Profoto Pro7.

Yes, freezing motion almost (there are other considerations) has nothing to do with the shutter speed, but the flash duration, provided that shutter speed is:
1, with the camera sync speed;
2, with the trigger sync speed (PW Plus II or III only supports 1/500 sec);
3, the most important, LONGER than the flash duration.

The later 2 conditions are not widely recognized by 99.9% photographers I have seen.:deadhorse:

Check the Pro7 user manual again, and you can see a flash duration chart on page 41. From that chart, you can see the shortest duration is 1/3000 at output setting from 300Ws to 18,75Ws, but you should also notice that flash duration is t0.5 which is about 3 times longer than the actual USUABLE duration of t0.1 (time of 90% powerpack output). That is to say you actually get 1/1000 sec flash duration from your Profoto.

Can that 1/1000 sec freeze that girl shot? It depends, because other factors can longer the flash duration, such as the age of the flash tube, the extension cable you use (the longer the longer).

If you stick on Profoto, the two choices to accomplish that kind of job are the Pro8 (which can reach 1/4000 sec flash duration t0.1), or the B4 which may reach 1/8000 to 1/10000 sec (it uses the cut-off technology as Broncolor does, but that sacrifices some color temperature stability) flash duration t0.1.

You can shoot the pouring water to test the true ability of your Pro7. From the beginning the water is at very low speed, and at the end it is at much higher speed, and you can see at which max speed the Pro7 can freeze the water.

Best,

Xin

Leading Cinema & Photography Equipment Rental House in China
 

geronimo13

New member
Considering your shooting condition: no modeling light, no ambi-light in the studio, which means a dark condition, that non-freezing problem in just because of the ability of the Profoto Pro7.

Yes, freezing motion almost (there are other considerations) has nothing to do with the shutter speed, but the flash duration, provided that shutter speed is:
1, with the camera sync speed;
2, with the trigger sync speed (PW Plus II or III only supports 1/500 sec);
3, the most important, LONGER than the flash duration.

The later 2 conditions are not widely recognized by 99.9% photographers I have seen.:deadhorse:

Check the Pro7 user manual again, and you can see a flash duration chart on page 41. From that chart, you can see the shortest duration is 1/3000 at output setting from 300Ws to 18,75Ws, but you should also notice that flash duration is t0.5 which is about 3 times longer than the actual USUABLE duration of t0.1 (time of 90% powerpack output). That is to say you actually get 1/1000 sec flash duration from your Profoto.

Can that 1/1000 sec freeze that girl shot? It depends, because other factors can longer the flash duration, such as the age of the flash tube, the extension cable you use (the longer the longer).

If you stick on Profoto, the two choices to accomplish that kind of job are the Pro8 (which can reach 1/4000 sec flash duration t0.1), or the B4 which may reach 1/8000 to 1/10000 sec (it uses the cut-off technology as Broncolor does, but that sacrifices some color temperature stability) flash duration t0.1.

You can shoot the pouring water to test the true ability of your Pro7. From the beginning the water is at very low speed, and at the end it is at much higher speed, and you can see at which max speed the Pro7 can freeze the water.

Best,

Xin

Leading Cinema & Photography Equipment Rental House in China

Finally somone that knows! :) Thank you so muhc I will test this as soon as I can.
 

studio347

New member
A question for the sync cord connection.
Did you use the sync splitter for 2 packs?
I think the best way for using 2 packs, is to use a cord splitter to connect 2 packs.

Nisha Multi Outlet Plug MOP B&H Photo Video

PS_make sure to turn off the power packs before connecting with this splitter(plug). Otherwise, the head(s) will pop up continuously in itself due to the uncontrolled loose? electricity... a guess.

For water splash shot, I prefer usually 1/4000-1/8000 s t0.1(!!!) which I can get through Broncolor... depending...
But for the falling object( ex. falling medicine pills), I can't get the usual sharp image even with 1/10000(t 0.1) s of the newer broncolor scoro packs. The sharp image we are seeing( ex. bullet flying) is captured using very special scientific power packs which I don't know about... I heard...
 
Last edited:

shlomi

Member
Flash unit for freezing motion:

Broncolor at $10,000
Einstein at $500

The Einstein freezes superbly, and after two years I can report no issues.
I treat my equipment very gently, so I can't attest to their sturdiness.
The Einstein remote control system is the best I've seen including Profoto, Bowens and Elinchrom.
 

studio347

New member
I have experienced the same problem. The solution is to use the twin-tube head. I have attached an example. Cheers
In theory, the bi-tube can shorten the duration half with an additional power pack. But the important condition for this is that the 2 power packs have to fire at the exact same time. I think Cell sync doesn't work since even though light speed is fast, the power pack firing operation time is not fast enough. The wired splitter sync might be an answer. But I didn't test it out yet_ the bi-tube + wired sync. Even if you can achieve 1/10000 s t 0.1 with the exact same time firing bi-tube, we can't freeze(relative term...) some moving subject depending on the speed... There is a certain limit even with the best equipment and the best practice with it :)
 
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