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Strobe Pack Power Question

jvora

Member
Hello :

While shooting interiors ( homes, hotels, etc. ) that have windows which streams pools of white-bright light what soft of power does one need in terms of watts/s for strobes ?

At present, I only have 400w/s strobes that I use for Products Shots - They are only useful for early morning / late evening shots and are absolutely inadequate for afternoon shots.

I do not have a place where I can rent lights for testing purposes thus am in need of advice based on your usage and experience.

I shall await your kind replies.



Jai
 

J.Look

New member
At present, I only have 400w/s strobes that I use for Products Shots - They are only useful for early morning / late evening shots and are absolutely inadequate for afternoon shots.
What kind of light formers are you using? There can be a difference of a few f-stops between different light formers.
Otherwise just use a light meter with your 400Ws lights and see how much is missing (measure the light coming in from the windows and the light from your strobes and see how big the difference is). If you are missing 1 f-stop you will need 800Ws, 2 f-stops 1600Ws etc.
 

neelin

Member
It's a tough question to give a definative answer. A sample photo of what you currently can't deal with would be most helpful.
Assuming you have a decent understanding of the inverse square law and how placement affects amount of light, you could do some partial tests yourself to get at least a portion of a scene correctly exposed. Then working back you could accurately calculate the w/s you need as you move back & add modifiers to cover the whole scene.
Also remember for your 'test' you can use the two 400 w/s units to make a 800 w/s flash. So in the general marketplace your choices of flashes more powerful than 800 w/s are pretty much 1200 w/s & 2400 w/s giving you .5 & 1.5 stops advantage.
At this point you should have a pretty good feel for how much power you need.
-----
Another way to figure the maximum amout of light you'd need would be to shoot a person face on, with their back to the sun (outside) using your flash & adjust the flash distance to equalize the light level back of head, front of face. So you've now figured how much light you need to overpower the sun. Just figure out how far back you'll have to place your light inside to get the illumination you want, and recalculate how many w/s you need using the inverse square relationship between distance & power. This would get you close to equalizing the sun output (of course indoors I'm not taking into account the light streaming in a window would have an equal amount of light applied from the flash, so it would be 1 stop brighter than ambient, but if you see where I'm going you'll be right in the ballpark of the amount of power you need.).
----
A flash meter would get you there faster.
Robert
 

jvora

Member
Thanks for the reply -

I understand my question was too open ended - Not sure if revising the question will help, but I'd liek to give it a try - Apologies in advance if the question still remains too open-ended -

I'll narrow it down by asking for the amount of W/s I will need if I were using one strobe for a regular sized Hotel Guest Room, ( say 15Ft x 20Ft ).

I then will try and extrapolate from there on in for other areas.

I hope the above criteria makes it more possible to answer my query.


Thanks,

Jai
 

jvora

Member
Your mentioning 2400 W/s does help as this is what I was considering.

As for a sample image - Attached please fine one.


Thanking you all for your assistance.


Jai
 

johnnygoesdigital

New member
If using just one strobe, I would shoot multiple images with the strobe placed in strategic locations in each image, blend in editing,(tethering is useful here). Use an ND gel or some diffusion material on window will help cut down ambient light. Increasing ISO will give you more latitude too.
 
Do a search on LuLa. There was a recent thread about aesthetic changes in architectural photography and there was some good info there. The reason you aren't getting a lot of response is that lighting equipment needs to be driven by your vision of how you want the photo to look, not the other way around.

You can do just fine with a single 400w strobe and some creative bracketing and PP work. You can use a dozen 400w strobes. You can use a 2400w pack with three heads, and a couple umbrellas. You can use a dozen 2400w packs running 1-3 heads each. You can use a truck full of hot lights. I'm not trying to be difficult or nebulous, I know and have worked with photographers that use all those methods. Some will get through many rooms in a single day, some will spend more than a day on a single room.

For me, it depends whether I am working solo or with assistants. If I am solo, I keep it to about three 500w monolights with a few grids and reflectors. If I have assistants, that goes to six monolights, a pack with a couple heads, and a case or two of hot lights. If I am shooting at night, it is all tungsten whether I have help or not. The end result is very similar, it is just a matter of how long it takes and how much is done in camera versus created in post, and whether I have more time on location or more time to work in the office.

If you don't have a clear vision in mind, maybe start with one or two 2400w packs with three or four heads, and keep your 400w head. That will allow you to raise the ambient in the room (most any room) to within a stop or two of ambient at any time of day. In my experience, being able to control the light is more important that the quantity of light, but different photographers work differently.

Before you do that though, I would start going through architecture magazines and other photographers websites to get an idea of what you like. When you have a clear vision, it is much easier (and less expensive) to build a lighting kit to support that vision.
 

jvora

Member
Hello Bill :

Really appreciate your reply - I certainly will head to the site you have suggested.

I normally do use Hot Lights, but face major issues when the room I am shooting has large windows while TONS of light poring through - Till date, I have managed to create the images via Post-Production Techniques, but felt that there has to be a better way.

I did try the 400W, but was not able to shoot at f/8 and would prefer to even shoot at f/10.

Overall, I get the desired results with hot lights - It's only when I have pools of bright light coming through that I feel that an appropriate strobe maybe the answer.


Thanks,

Jai
 

jvora

Member
Hi Bill :

Can I request you for LuLa's URL - DId a search on google for it and found several -
Is it the Lula Magazine ? or Lula.se ?

Sorry for the bother -


Jai
 

robertwright

New member
ask yourself, what am I going to see out the window if the exposure is balanced- and is it worth it?

if you look at high end interior magazines like World of Interiors, Elle Decor, Nest, Dwell, etc, the answer is usually "nothing".

If you look at consumer driven real estate photography with over cooked HDR effects then the answer is "a perfect day".

I think the question is totally aesthetic driven and probably client driven. But I'd prefer to educate my clients to prefer the former and eschew the latter.
 

jvora

Member
Thanks - Neelin - Did not make the obvious connection. even though I visit the site almost daily - I now know that the short form ;)

Thanks,

Jai
 

figure1a

New member
It depends on shutter speed. If you can get a faster shutter (like Phase One 1/1600th) then you could probably do the job with a speed light.
 
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