Paul C. Buff, Inc. Technical Forum

Technical Discussion Forum for all Paul C. Buff, Inc. Products

Login

Post a reply
 [ 7 posts ] 

Sun Aug 17, 2014 2:59 am

Joined: Sun Feb 16, 2014 8:05 am
Posts: 4

I've owned my alienbee's since February and I still haven't learned how to correctly use the modeling lamp to have WYSIWYG results. I have 1 b1600 and 2 b800s. My modifiers are the Octobox from the busy bee package, the 20° grid for the reflector, and the PLM umbrella. I originally thought because my low ceilings and the light bouncing everywhere was my issue, but now that I just moved into a place with huge ceilings I'm still having problems getting it right.
Before the Bees I shot with speedlites, so I was excited for this feature. And new to it. Can anyone share some tips on how to get some good results?




Top Top
Profile
 

#

Sun Aug 17, 2014 2:06 pm

Site Admin
Joined: Tue Dec 08, 2009 11:49 am
Posts: 1432

Modifiers used don't really matter.

The principle of WYSIWYG is is simply to maintain an equal ratio of modeling lamp Lumens vs flashpower Lumen Seconds. This is easier to approximate by thinking model watts vs flash Ws.

So if one light is 640Ws and has a 150W model lamp it has a ratio of 640Ws to 150W modeling (4.25:1)

So if another light in the setup has 320Ws, its modeling lamp should be 1/2 the wattage of the 640Ws flash, or 75W. Thus, as long as the "Track flash" button is IN on the ABs, the 320Ws Bee will produce half the flashpower and half the visual model light as the 640Ws Bee, and the difference you see with modeling lamps will be proportional to the amount of flash exposure the camera sees.

So your B1600 should have the standard 150W model lamp and each B800 should be changed to a 75W household bulb.

For this to work properly, the shooting area should be kept free of ambient light so all you see in composing is the light from the modeling lamps.

If Einsteins are introduced into the system, they have a model lamp offsetting capability, so you can set an Einstein such that its model lamp produces 150W when the flash is set to 640Ws. This offset will track all flashpower adjustments (as will the Bees) so a constant ratio of flashpower to model watts will result as long as the "Track Flash" or "Proportional" mode is used on all lights.

If a B400 (160Ws) were added, it should use a 40W model lamp to maintain the same ratio. Fortunately, various wattages of household bulbs are still pretty available.

Given these ratios, what you see with model lamps should be very close to what the camera sees from the flashes . . . but only if the room is kept otherwise dark. One caveat is that the eye sees a wider range of contrast than the camera so some power adjustments may still be need for exacting results.




Top Top
Profile
 

#

Sun Aug 17, 2014 10:21 pm

Joined: Sun Feb 16, 2014 8:05 am
Posts: 4

Thank you for the reply. I read about the different watts during my purchase. That's why I tend to use the b1600 with grid for the hair light if needed so I can balance out the b800s equally. Maybe I'm jumping in too fast with all 3 at once and I'll need to build the look one light at a time. I make adjustments by what comes out of the camera but would love to actually find WYSIWYG sometimes.




Top Top
Profile
 

#

Mon Aug 18, 2014 11:08 am

Site Admin
Joined: Tue Dec 08, 2009 10:43 am
Posts: 5266

Unfortunately, you will never get a absolutely true WYSIWYG, since the human eye which has more dynamic range than the camera, which, in turn, has more dynamic range than printing and display media. This would be true of any light system.




Top Top
Profile
 

#

Wed Aug 20, 2014 2:33 am

Joined: Tue Aug 12, 2014 3:41 pm
Posts: 2

WCWC924 wrote:
I've owned my alienbee's since February and I still haven't learned how to correctly use the modeling lamp to have WYSIWYG results.


For what it's worth I've had White Lightnings for decades and truthfully I used them pretty infrequently so I was never a MASTER. It was quite frustrating getting the modeling lamps to show me truly what I want. I would have this great portrait setup with the background light just right with just a strip of light going down, but when I took the picture the seamless paper was all lit up without any strip of light. I basically couldn't figured it out. I even tried using velvet as a background to use as a light absorber hoping that would help but it just sucked up all the light giving me a totally black background.

For regular exposures of the main subject I would just used my light meter for ratios and to check the settings I used a lot of Polaroids and thankfully, digital in the modern era. However, in the past year, I decided to try a variable ND filter I purchased last year. Low and behold I'm able to get WYSIWYG! I'm also able to get the wider apertures I always desired. I don't know why I never bothered using a ND filter before, but now that I did I'm always going to use one. I used to just drop the power down but sometimes I ran out of low power in some fill lights because the main light was set so low. The ND filter fixed that.

So, maybe you just need to do what I did and get a ND filter and see if that works for you. It looks like a 3 or 4 stop ND filter is the one I use the most.

Good luck!




Top Top
Profile
 

#

Wed Aug 20, 2014 10:33 am

Site Admin
Joined: Tue Dec 08, 2009 10:43 am
Posts: 5266

Typically, "what you see is what you get", in the case of modeling lamps, refers to the ratio of light coming from one light vs. another. An ND filter for the lens would lower the total amount of light, however the ratios would remain the same, but at a lower effective level, as well as lowering the amount of flash and model lamp by the same amount. Therefore, I don't see how the ND filter would affect WYSIWYG in the manner we are describing.


However, you are very much correct that a ND filter will allow for shallower Depth of Field by lowering the amount of light present, which in turn allows a wider aperture.




Top Top
Profile
 

#

Wed Aug 20, 2014 9:37 pm

Joined: Thu Jun 14, 2012 9:44 am
Posts: 100
Location: Chicagoland, USA

WCWC924 wrote:
I've owned my alienbee's since February and I still haven't learned how to correctly use the modeling lamp to have WYSIWYG results. I have 1 b1600 and 2 b800s. My modifiers are the Octobox from the busy bee package, the 20° grid for the reflector, and the PLM umbrella. I originally thought because my low ceilings and the light bouncing everywhere was my issue, but now that I just moved into a place with huge ceilings I'm still having problems getting it right.
Before the Bees I shot with speedlites, so I was excited for this feature. And new to it. Can anyone share some tips on how to get some good results?


Not to at all discount what Paul C. Buff said because I am quite sure he right, but I have never used modeling lights for WYSIWYG. I have only used them to check the direction of light, placement of shadows, to reduce pupil dialation as much as possible, etc. Remember, AlienBees are strobe lights - not hot/constant lights.

When I want to exactly control brightness (exposure) in areas of a portrait, I just flashmeter each strobe separately. I don't know of an easier and more sure way to do it. For a three-light setup it usually takes 5 minutes or less, and in this DSLR age you just use the LCD to see if you are getting what you want.

We can't know for sure what type of look you want, but hopefully this example might help a bit:

If I am putting F/5.6 worth of strobe light on my subject's face and I want rear/shoulder light on a backdrop to be two stops lower, then I flashmeter that STROBE output (not modeling light output) to F/2.8.

https://www.flickr.com/photos/92211832@N04/13884128176/

A full description of the light setup for this portrait is below the photo.

There are of course variables that will affect the result. A gridded softbox was used here as keylight. If an umbrella was used instead, the overall light would have been much flatter and less directional, and the rear light would be much less defined. The subject here was about 7 or 8 feet away from the backdrop. If everything else was kept equal and he was moved closer to the backdrop, the light on the backup would again become flattened out and less defined. The farther he is moved away from the backdrop, the greater the light fall-off behind him would become. The light on the backdrop would also appear tighter and more defined because it would appear smaller relative to the size of the subject and also due to being farther away. BTW, this was done on location; the room was large but the ceilings were relatively low - probably 8 feet high.

This was a pretty straight-forward portrait, but I can't imagine using modeling lights for WYSIWYG exposure when it comes to something like this re-creation of Normal Rockwell's "Girl at Mirror" where metering had to be absolutely exact to get the strobe/light ratios right:

https://www.flickr.com/photos/92211832@N04/8381528124/

As Tech Support also said, an ND filter has nothing to do with WYSIWYG. If you want to shoot your keylight at F/1.4 and you are already at you lowest ISO but the lowest you can reduce your strobe output to and meter it at is F/2.8, that is where the ND filter comes in. Side note/reminder: you can ND strobes as well as lenses.

Craíg

http://www.craigwasselphotoart.com




Top Top
Profile
 
Website
 
Display posts from previous:  Sort by  
Post a reply
 [ 7 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: Google [Bot] and 90 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum


cron