Strobe lighting power question

Nimitz · Jul 12, 2007

I'm getting ready to purchase my first studio strobe lighting setup. Although I've been shooting for many years I don't have any experience with studio strobes so I've been doing a lot of reading and the one area I'm still have trouble with is understanding what power of strobes I should be looking at.

I will be setting up a home studio focusing mostly on glamour & portrait work so I'm looking at kits that have 4 strobe setups (key, fill, background & hair/rim) but I don't really understand the difference between a 500 w/s strobe, 300 w/s or 150 w/s, etc

Are there some rules of thumb for determining how powerful strobes to get?

Thanks for any advice or somewhere to go read up on this ...

Garbz · Jul 12, 2007

I think more power = more versatile in a varied range of situations. You can always turn the power down, but you can not turn it up.

It depends on the aperture you will be shooting at, the light to subject distance, etc and you need to tailor it to your situation. If you're trying to light up from across a larger room, 150w/s will not be enough.

Mad_Gnome · Jul 14, 2007

Don't just look at power ratings either. There are a lot of factors to consider when buying strobes. You'll also need to consider: durability, strobe life (number of flashes), adjustability (5-stop adjustability is a lot better than 2- or 3-stop), manufacturer reputation, customer service, etc. I'd recommend against buying the typical eBay generic strobe kits. They're generally of very low quality, and customer service can be a shot in the dark. Look at name brand manufacturers, as there are plenty of them that offer high quality lighting for not a lot of money. Alien Bees and Novatron seem to be the top two players in the entry-level strobe lighting category.

Also, be aware that power ratings can be deceiving. The Ws rating of a strobe is simply a measure of the power it draws as it recycles, and has much less impact on usability than you might think. Guide numbers are a better method of measuring a strobe's usable output, but Lumen-seconds is the rating you truly want to get if you can. This is one of the reasons Alien Bees are such a highly sought-after light. Their Ws ratings appear to be fairly low, but because of the quality of the engineering behind their design, their light output is far beyond any comparable lights from other manufacturers.

Nimitz · Jul 14, 2007

thanks for the info. I've been doing more research and also discovered that GN is what I should be looking at as well. If I understand it correctly, GN is F-stop times distance from subject to strobe. Therefore, if I'm looking to shoot at f-11 and want to place the strobe 10ft from the subject I would need a strobe with a GN of at least 110 at full power. Also, I know that umbrellas typically half the GN so I'd really need a strobe with a GN of 220 w/STD reflector. What does a softbox do to the GN?

I guess it would also be nice if at the maximum distance I expect my strobe to be from my subject that I could get f-11 at less then the strobe's max power to have some extra cabability. Since for most portrait & glamour work depth of field and freezing motion are not a concern I would expect to be shooting at f-8 or f-11 most of the time.

Does the above all make sense?

I've also seemed to have centered around Alien Bee strobes. I like the fact that you can build your own strobe kit & still get their standard kit discounts.

Big Mike · Jul 16, 2007

Welcome to the forum.

It sounds like you have a pretty good idea of what you might need...at least a better idea than most first time purchasers. I have a few AlienBee lights and I can recommend them. They are a good 'entry level' studio light product and the company is run pretty well. They (Paul C. Buff) also has a pro line called WhiteLighting.

As mentioned, you can always turn the power down but you can't get more than 100% out of them. So buy lights that are powerful. The AlienBee B800 light is probably powerful enough for a main light in a home studio, it seems to be the most popular model from what I can tell. I have two of them and a B400 for a background light.

jstuedle · Jul 16, 2007

Guide number can be deceiving. A manufacturer can change a reflector design and bump up their GN, while comparing there light to another's with a more broad field of coverage, or worse yet a bare bulb without a reflector at all. I am not aware of any independent testing to even out the playing field so that all strobes are measured the same way. Best bet would be to visit a few studios and ask around, look at their setup and ask about power settings for typical portraits. BTW, I can highly recommend the Calumet Travelight made by Bowen. I own a set and they are very durable.

Nimitz · Jul 17, 2007

Thanks all for the comments. I thought about only getting B400s for my background & hair lights but then thought I'd be better off if all my strobes were the same so I didn't have to worry about which strobes to put where for lighting ratios given the different power outputs. For the extra 100 bucks it just seems easier to get all 800s.

Also since I plan to use the system for in-home location shooting as well as my small studio it makes sense to get the more powerful 800s because I may need more power on location.

I'm looking forward to playing around with the strobe lighting.

BTW ... anyone know someone in the market for a 1500W tungsten equivalent, 4 light, 2 softbox setup of 5200K daylight balanced 'cool light' flourcesent continuous lighting? The setup is less than 6 months old & in perfect condition ...

Digital Matt · Jul 17, 2007

In addition to what has been mentioned, it's important to point out that the more powerful the strobe, the less likely that you'll be shooting at full power, which means the lights will recycle faster. You never want to be shooting at full power if you can help it. Buying bigger wattage lights so you can shoot in the mid range will prolong the life of the bulb and give you quick recycle times when you are shooting repeatedly.

Nimitz · Jul 18, 2007

another great point !

table1349 · Jul 18, 2007

Man, I would say that you all have just about covered it. Kind of like when I was a kid. I wondered why my old farmer granddad always wore long sleeve shirts every day of his life, so I asked him. His answer was simple. "Boy, if it gets hot I can always roll em up, but you just try rolling them short sleeves of yours down." :lol:

Now you got me thinking of AB1600's instead of the AB800's. Anyone here used the AB Zeus units yet. Look interesting.

Alpha · Jul 18, 2007

I would always go WL over AB. The build quality is just better. They cater to slightly different markets. I don't think the Zeus package is worth the money. Unless you need to mount your lights way up on a boom, there's no reason to go pack over monoblock for that much of a price increase. I'd rather take a small monolight and a battery pack. It's cheaper, too.

table1349 · Jul 19, 2007

I would if I was doing this for a job, but since this is a hobby the AB's are good enough for me. Besides, they are made by WL for AB.

Nikon Norm · Jul 19, 2007

I have the Alien Bees, had them for about 18 months, have 2 1600's and two 800's and am going to get 2 400's.

They have been used on location and in a studio, have shot lots with them, they still seem like new. The durability question seems over played, they are great value for money and they work.

I use light modifiers all the time I have a 2' and 5' soft box as well as umbrellas and run the 1600 for full length and portraits at around 1/4 power with the soft boxes, so in reality the 800's would be plenty.

The other neat feature are the available colors the housings come in, I buy each power level a different color, so my 1600's are yellow, the 800's are green, so just by looking at the housing I know which strobe power I'm using.

Good luck with your choice

sabbath999 · Jul 19, 2007

I agree with everyone else on getting more powerful lights and stopping them down...

Alpha · Jul 19, 2007

It's not durability I'm talking about. It's output consistency.

I also don't trust anyone who markets their lights in effective w/s, even if they also provide real w/s. If they were everything the company claimed them to be, there would be no need for gimmicky marketing. The quality of the product should speak for itself. And the quality of a strobe depends upon much more than the ability to put out a burst of light.