Lens Diaries Go Now
Glamour, Beauty, Nude, Models, Photographers

*    |  Register  


 
Go Back   Garage Glamour™ > Garage Glamour™ Main Forums > Tech Talk Forum
 

Tech Talk Forum Photography & Technical Related Only!

Reply
 
LinkBack Thread Tools Display Modes
Overpowering the sun with strobe?
Old 03-11-2007, 09:10 PM   #1 (permalink)
Free Member
 
Join Date: Oct 2006
Member GG#: 55362
Location: Benton
Posts: 242
Comments: 0

nakins is offline IP: 70.232.115.36
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

I'm trying to perpare for a opprotunity to shoot motorcycles and possibly cars in June. I've tried to find locations to do this that have a nice background, but all I've been able to come up with is a parking lot, with a parking lot on either side and behind it. No old building to shoot against. Just crap. So, I thought of trying to minimize the background has much as I can by over powering the sun light with 1200ws + strobe and a ND filter.

If I'm using a strobe of over 1200 ws to light a person full lenght, how much exposure difference could I hope to have between the full blast strobe lit subject and the sun lit back ground?
  View Public Profile Send a private message to nakins Find More Posts by nakins
 
Re: Overpowering the sun with strobe?
Old 03-11-2007, 10:10 PM   #2 (permalink)
Free Member

 
R_Fredrick_Smith's Avatar
 
Join Date: Jun 2003
Member GG#: 35872
Location: Dallas/Fort Worth Area
Posts: 3,691
Comments: 41

R_Fredrick_Smith is offline IP: 76.186.138.153
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Quote:
Originally Posted by nakins View Post
I'm trying to perpare for a opprotunity to shoot motorcycles and possibly cars in June. I've tried to find locations to do this that have a nice background, but all I've been able to come up with is a parking lot, with a parking lot on either side and behind it. No old building to shoot against. Just crap. So, I thought of trying to minimize the background has much as I can by over powering the sun light with 1200ws + strobe and a ND filter.

If I'm using a strobe of over 1200 ws to light a person full lenght, how much exposure difference could I hope to have between the full blast strobe lit subject and the sun lit back ground?
In the digital age its easy to figure this out. Just go out and set the camera to f11 (for example). While shooting in manual choose your camera's max sycn speed. Shoot the shot. Is it dark enough so you can't see parking lots in the shot? If not, try at f16 and so forth, or add ND filters. When you find the combination that gives you a dark background, then for that fstop meter the flash on the subject. So suppose you get everything as dark as you want at f22, then you would keep the camera at f22, and meter the lights till you get the power or distance set to give you f22 reading on the meter. Keep in mind if you use ND filters you'll have to compensate with more flash power or move it closer. But you can tell in the LCd if you're getting what you want.

Note: Second approach. Get a ladder. Shoot down onto the scene and you'll have just the surface of the parking lot around the subjects as the background.

Cheers,
rfs
__________________

"The map is not the Territory"
  View Public Profile Send a private message to R_Fredrick_Smith Visit R_Fredrick_Smith's homepage! Find More Posts by R_Fredrick_Smith
 
Old 03-16-2007, 04:27 AM
Miles Abramovich
This message has been deleted by Miles Abramovich. Reason: rfs, you're right, I'm wrong. I am outta here.
Re: Overpowering the sun with strobe?
Old 03-16-2007, 09:07 AM   #3 (permalink)
Lifetime Photographer

 
RonC's Avatar
 
Join Date: Sep 2003
Member GG#: 36882
Location: Antioch,Ca.
Posts: 1,048
Comments: 2
My Mood:

RonC is offline IP: 24.23.181.251
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Quote:
My explanation is very clumsy but I hope that you get the gist of it
I like your explanation.
__________________
RonC


---------------------------------------------------------------------
Nothing stays as good as it once was!
http://www.myspace.com/ronsphotos
  View Public Profile Send a private message to RonC Visit RonC's homepage! Find More Posts by RonC
 
Re: Overpowering the sun with strobe?
Old 03-16-2007, 09:16 AM   #4 (permalink)
Lifetime Photographer

 
lsc1's Avatar
 
Join Date: Jul 2003
Member GG#: 36482
Location: Charleston
Posts: 528
Comments: 2

lsc1 is offline IP: 65.0.227.80
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

That was a great first post Miles, you're going to be handy to have around here. Welcome and thanks for taking the time to respond in a very clear explanation of these confusing principles.
__________________
Cheers,
LSC


"The girlshapedlovedrug messes with my mind." Gomez (the band)
  View Public Profile Send a private message to lsc1 Find More Posts by lsc1
 
Re: Overpowering the sun with strobe?
Old 03-16-2007, 12:07 PM   #5 (permalink)
Free Member

 
R_Fredrick_Smith's Avatar
 
Join Date: Jun 2003
Member GG#: 35872
Location: Dallas/Fort Worth Area
Posts: 3,691
Comments: 41

R_Fredrick_Smith is offline IP: 76.186.138.153
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Quote:
For example, you measure the ambient light as aperture F8, shutter speed 1/30s. To balance the flash with the ambient light, you set your flash to output F8. In this example, if you wish to make your background black, set your shutter speed to three stops below 1/30s, i.e. 1/250s. Your flash exposure still remains as F8 but the ambient light level has been cut down three stops to 1/250s.
The problem however arises in bright sunlight that you'll end up having to raise the shutter speed highter than 1/250th and that is beyond the sync speed limits of most of the people shooting with dSLR cameras. You example will work just fine if the light is very low. But suppose its a bright day. Using the sunny 16 rule we would figure f16 at 1/100th (iso100) for the exposure (and be in the ball park). Now if we change our shutter speed by 3 stops we are at 1/800th which won't work because the dSLR camera's have a sync speed of 1/250th or below. So now we have to stop down more for the fstop or use ND.

Cheers,
rfs
__________________

"The map is not the Territory"
  View Public Profile Send a private message to R_Fredrick_Smith Visit R_Fredrick_Smith's homepage! Find More Posts by R_Fredrick_Smith
 
Re: Overpowering the sun with strobe?
Old 03-21-2007, 09:14 AM   #6 (permalink)
Free Member
 
Join Date: Dec 2006
Member GG#: 56517
Location: Montreal
Posts: 6
Comments: 0

gilp is offline IP: 70.50.254.25
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

I think that a 1200w/s flash may be a bit low power in bright backlit days, I use the ProFoto D4 ring light at 2400w/s and using the very valid technique discribed earlier, I sometimes need to had an external light source such as a hmi1200 daylight par.

the sun is a hard light to beat, thank god for iso50 !!
  View Public Profile Send a private message to gilp Visit gilp's homepage! Find More Posts by gilp
 
Re: Overpowering the sun with strobe?
Old 03-21-2007, 01:02 PM   #7 (permalink)
Free Member

 
R_Fredrick_Smith's Avatar
 
Join Date: Jun 2003
Member GG#: 35872
Location: Dallas/Fort Worth Area
Posts: 3,691
Comments: 41

R_Fredrick_Smith is offline IP: 76.186.138.153
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Quote:
Originally Posted by gilp View Post
I think that a 1200w/s flash may be a bit low power in bright backlit days, I use the ProFoto D4 ring light at 2400w/s and using the very valid technique discribed earlier, I sometimes need to had an external light source such as a hmi1200 daylight par.

the sun is a hard light to beat, thank god for iso50 !!
Actually 1200ws is more than enough. That would give us a guide number of somewhere around 450 at iso 100. By the sunny 16 rule, we would have f16 at 1/100th, but we can go up to 1/200th and still be in our sync speed. So that buys us a stop. You could then change to f22 which would buy another stop. So now we've reduced the effect of the sun by 2 stops. Now change to f32 and we have bought 3 stops reduction which will be quite dark for the background.

So, will the 1200 WS flash at GN 450 work at f32? Let's check. Divide 32 into 450 and you get about 14'. So if we put the flash at 14' the model will be well exposed and we will have a dark background. Suppose we use a less powerful flash with a GN of 320. Then you simply put the flash at 10'. But we could move the flash even closer, so we could go with a flash with even less power. But, the more flash power you have the more flexibility, such as lighting a larger area.

Cheers,
rfs
__________________

"The map is not the Territory"
  View Public Profile Send a private message to R_Fredrick_Smith Visit R_Fredrick_Smith's homepage! Find More Posts by R_Fredrick_Smith
 
Re: Overpowering the sun with strobe?
Old 03-21-2007, 05:40 PM   #8 (permalink)
Free Member
 
Join Date: Mar 2007
Member GG#: 57919
Location: LA
Posts: 581
Comments: 1

kgphoto is offline IP: 69.235.170.172
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Of course the big problem here is the cars will not look very good with only a point source to light them. Normally you shoot at Sunset or Dawn and use open sky as the light source or a large silk/lightbox if you use strobe.

We typically start at around 6000 W/S of strobe for this type of image and frequently more.
  View Public Profile Send a private message to kgphoto Find More Posts by kgphoto
 
Re: Overpowering the sun with strobe?
Old 03-22-2007, 08:31 AM   #9 (permalink)
Free Member
 
Join Date: Dec 2006
Member GG#: 56517
Location: Montreal
Posts: 6
Comments: 0

gilp is offline IP: 70.50.254.25
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote

Quote:
Originally Posted by kgphoto View Post
Of course the big problem here is the cars will not look very good with only a point source to light them. Normally you shoot at Sunset or Dawn and use open sky as the light source or a large silk/lightbox if you use strobe.

We typically start at around 6000 W/S of strobe for this type of image and frequently more.

I agree, while the formulas do make a lot of sense, it's my personal real life experience that 1200w/s does not cut it... especially with a ringlight wich is so broad that very little light actualy reaches the subject...
  View Public Profile Send a private message to gilp Visit gilp's homepage! Find More Posts by gilp
 
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Elinchrom's New Ranger Quadra Battery-Powered Strobe System jimmyd Tech Talk Forum 1 09-08-2009 02:35 PM
1st strobe wrwhite Tech Talk Forum 24 04-12-2006 08:00 PM
Photoflex Octo connector or Strobe Connector (aka speed ring?) objektiv Tech Talk Forum 1 10-14-2003 12:50 PM
Methods for Overpowering the Sun Dman65 Tech Talk Forum 6 06-24-2003 03:36 PM

Sponsors


New To Site? Need Help? Photographer & Model Links
All times are GMT -5. The time now is 05:10 AM.

© 1999-2017 Garage Glamour™




Search Engine Friendly URLs by vBSEO 3.2.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94