S/S2 and studio flash

[GMB]

I have very little (actually close to no) studio experience. However, I wanted to use the S2 for some studio portraits. I don't have the CS lenses, so I understand that the lowest shutter speed that I can use is 1/125th. Now here is my question: How do I avoid motion blur when shooting with the 120mm and the 180mm, for which I would normally use at least 1/250th or 1/360th when shooting handheld? Are tripod / monopod the only solutions (other than 2 weeks without coffee)?

Thanks.

 

[baudolino]

I guess it depends on the level of ambient light. The flash duration is very short so there won't be any motion blur if the ambient light is low and most of the illumination comes from the flash. If the level of ambient light is high and you use the flash only as fill-in, then, in theory, you could experience motion blur - but that's not a likely scenario since you will need high sync speed (and therefore CS or HC lenses) in the first place, unless you want to shoot at f16-22 all the time (or use ND filters), otherwise the high level of ambient light will result in overexposure. The ND filter can be a good solution if you don't have CS lenses (you can watch Joey L's film on his portrait project in Ethiopia where he uses a Phase One body/digiback with a battery operated studio flash and balances the ambient and flash illumination using an ND filter). In summary, if you shoot in a studio and all illumination comes from flash heads, you don't need to worry about sync speeds and motion blur. If you shoot outside, or elsewhere with high level of ambient light, you need to use either high speed sync (CS/HC) or ND filters (and you may indeed experience some motion blur with the ND filters).

 

[anGy]

I have very low experience in shooting people in studio (using it for product/still life usually).
But I made a session last sunday with kids jumping in the air. Using iso 35 and f16 on an IQ back (and using huge softbox) definitively gave me some motion blur (especially on the hands) as my Bron Grafit system speed was as low as 1/125s.
Had no choice but to rise the iso of the IQ back to 100 and lower the power output of the generator to gain some speed . 1/750s solved the issue but not totally.

The S system native iso is 160 I guess so motion blur should not be a problem unless for combination of fast moving subject and low power flash system.

 

[GMB]

Thanks. Not sure I fully understand. If I want to shoot at f8 and ISO160, I set the camera 1/125 (the sync speed) and f8, the desired aperture. How do I set the flash using an ambient light meeter to make sure that I don't expose longer than say 1/250 or 1/500?

 

[rsmphoto]

Strobe exposure is governed solely by aperture, ambient light exposure by shutter speed. Since it sounds like you don't have a flash meter, you'll have to do some test shots to dial in exposures for ambient and strobe, looking at your histogram and camera screen. If you're in a studio and you don't care about ambient light exposure, then leave the camera at 1/125 and forget about it.

Alter your power settings on the strobe's power pack to fine tune strobe exposure since you want to stay a ƒ8 (or move your subject further from or closer to the light source). Ideally, you could shoot tethered with Leica Image Shuttle and LR 4 or 5. Then you can see everything clearly.

Best,
Richard

 

[RVB]

Thanks. Not sure I fully understand. If I want to shoot at f8 and ISO160, I set the camera 1/125 (the sync speed) and f8, the desired aperture. How do I set the flash using an ambient light meeter to make sure that I don't expose longer than say 1/250 or 1/500?

only aperture and iso matters with strobes,shutter speed is used to control ambient light,

S2 native iso is 160 but S is 100...

 

[baudolino]

Thanks. Not sure I fully understand. If I want to shoot at f8 and ISO160, I set the camera 1/125 (the sync speed) and f8, the desired aperture. How do I set the flash using an ambient light meeter to make sure that I don't expose longer than say 1/250 or 1/500?

I suggest you get a basic flashmeter (for example the relatively small and cheap Sekonic L308S which I use). You then set the ISO on the flash meter (the same that you have set on the camera), tether the flash meter to the strobe head or battery/generator unit (as relevant) with the sync cable and fire a test shot using the dedicated button on the flash meter. The measuring cell has to be covered with the milky cover "dome" and facing the camera. The flash meter gives you the the required aperture for the selected output of the flash (as usual, the reading is valid for the mid-gray exposure - so you may want to experiment, depending on your creative intent). You can achieve different aperture either by adjusting the flash output (on the head or the battery unit) or by moving the strobes further from the model. As stated above, the sync speed is irrelevant when working with strobes as your single source of light.

 

[Shashin]

I wouldn't even both with a flash meter, just take some exposures. It is just like the good old days with Polaroids, only you do not have to change backs and wave your Polaroid in the air for a minute. (I don't know why every photographer waved their Polaroid--it had nothing to do with development.)

The lower the power on your strobes, the faster the flash duration. I have used my Pentax 645D in the studio and that has a sync speed of 1/125, but the flash duration is what stops the motion.

In the studio, there are three controls for exposure--aperture, flash power, and flash to subject distance, at least for a particular ISO and without going into ND filters.

 

[GMB]

My second post was unclear. Apologies for that. I actually had access to a flash meter. So setting the strobes to the right amount of light was not the issue. The issue is really how to avoid motion blur because of camera shake. Or is it that the flash in any event is shorter than 1/125 so that I don't have to worry too much?

 

[Shashin]

Flash duration is what is going to freeze the action and can be much much shorter than 1/125s depending on the power level set on the flash unit.

 

[baudolino]

Typical flash duration is something like 1/1.000th to 1/10.000th of a second and perhaps even faster, depending on the power, as stated above. I think some Profoto models can go as fast as 1/25.000th of a second. You can freeze almost any motion with flash, including water droplets in the air, or the famous bullet being shot through an apple. If you need really high power, then (depending on the model) the flash duration may be slower than 1/1.000th of a second, but still fast enough for your intended use. So no worries, it will definitely take care of any motion blur caused by hand holding your camera.

 

[sortvitt]

Two scenarios:
1. Ambient light in studio.
Use a tripod. 1/125 on the S is likely to give you some visible shake handheld, at least it does for me.
2. No ambient light.
Both handheld and tripod works fine. You will not see any camerashake as the strobe will freeze things nicely, as mentioned by others.
Good luck! The S is a beast in studio

 

[rsmphoto]

Yeah, what they said.

Keep ambient low
and you're good to go.