White line on gray seamless

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Archive 2010 · White line on gray seamless

jwboring
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p.1 #1 · White line on gray seamless

I am using thunder gray seamless for the first time and keep getting this white line in the fold. The fold being right where the paper rises from the floor. Of course, the line goes away if I eliminate all light from hitting the seamless. However, I was under the impression that the gray would be kind to a little spill. Is this not the case?

Also, what kind of angle are you suppose to have in the fold anyway? I've been using close to 90 degree and not had the issue with white or black. I notice now with the gray that if I stretch the paper out so the fold is very gradual the line is less acute, but still there.

Jeff

Feb 07, 2010 at 03:02 AM

NinaS
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p.1 #2 · White line on gray seamless

why are you folding? isn't the point of "seamless" to have no fold or seam
let it flow in a gentle arc to the floor for best results

Feb 07, 2010 at 05:50 AM

jwboring
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p.1 #3 · White line on gray seamless

why are you folding?

Bad choice of words on my part. I am letting it flow in a gentle arch to the floor. There is always a white line in that arc when light is hitting it. The arc itself is lighter than the seamless on the floor and seamless just above the arc thus producing the line.

Jeff

Feb 07, 2010 at 01:01 PM

cgardner
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p.1 #4 · White line on gray seamless

What you are seeing may be glare caused by a reflection of spill of your shooting lights off a white ceiling.

The angle of reflectance is equal to the angle of incidence and curved surface will pick up reflections from a wide range of angles. If it is being caused by reflected spill if you change the position of your camera vertically the line will move up/down in the opposite direction. To prevent it use light sources which don't spill light onto the ceiling and walls.

Feb 07, 2010 at 01:18 PM

Micky Bill
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p.1 #5 · White line on gray seamless

You may need a larger gentle arc, not a small one. Think a 2 to 3 foot radius.

Feb 08, 2010 at 01:32 AM

TTLKurtis
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p.1 #6 · White line on gray seamless

A photo would also help.

Feb 08, 2010 at 04:01 AM

jwboring
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p.1 #7 · White line on gray seamless

A photo would also help.

One light - ab bd - in the butterfly position, 3 ft over the models head.

Bad pics, I know but only ones I had handy to show the white line.

Edited on Feb 14, 2010 at 01:38 AM · View previous versions

Feb 08, 2010 at 01:04 PM

jwboring
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p.1 #8 · White line on gray seamless

Here's another pic - jpeg direct from camera

This image is copyrighted by the owner

3 lights- 1 st umbrella from behind, 2 lights in front on each side.

cgardner: I don't think that's what it is because the line doesn't move. Plus, no line appears when the sb is pointed sideways, ie no direct light hitting the seamless.

Jeff

Edited on Feb 09, 2010 at 02:20 AM · View previous versions

Feb 09, 2010 at 02:13 AM

HappyCamp
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p.1 #9 · White line on gray seamless

I think you have to sharp of a turn.

Most times I see it done with a large sweeping curve, if you have the room.

Also your white balance seems off in the images

Feb 09, 2010 at 02:19 AM

swanny338
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p.1 #10 · White line on gray seamless

Softer arc, that is all that is needed.

Feb 09, 2010 at 02:20 AM

jwboring
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p.1 #11 · White line on gray seamless

Thanks Happy. Yes, we did a visual test with a large sweeping curve and the line got fainter but was still there. Didn't have time to shoot it. Will try again this weekend.

white balance seems off

Yes, ab lights, not adjusted.

Feb 09, 2010 at 02:23 AM

RobertLynn
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p.1 #12 · White line on gray seamless

Your picture of the girl has double shadows and a lot of sensor dust.

Sorry I can't help with the line, but clean your sensor

Feb 09, 2010 at 02:48 AM

TTLKurtis
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p.1 #13 · White line on gray seamless

Yeah the radius of your curve is too small.

Feb 09, 2010 at 04:03 AM

s14brent
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p.1 #14 · White line on gray seamless

the wb issue has nothing to due with the lights being alienbees, i hope thats not what you were implying.

Feb 09, 2010 at 09:58 AM

jwboring
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p.1 #15 · White line on gray seamless

wb issue

I set the camera for flash but always shoot a gray card. Then adjust the wb in ps. The above image has not been adjusted in ps, it's the jpeg straight out of the camera. I understand that I could set a custom wb but have not gotten around to that.

double shadows

Hum, didn't notice that. I guess that is the result of lights on both sides

I guess double shadows are a no-no. Does that mean you never use lights on both sides?

I'll try a wider arc this weekend. Thanks for all the help. This forum has been wonderful for me.

Jeff

Feb 09, 2010 at 01:20 PM

RobertLynn
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p.1 #16 · White line on gray seamless

jwboring wrote:
wb issue

I set the camera for flash but always shoot a gray card. Then adjust the wb in ps. The above image has not been adjusted in ps, it's the jpeg straight out of the camera. I understand that I could set a custom wb but have not gotten around to that.

double shadows

Hum, didn't notice that. I guess that is the result of lights on both sides

I guess double shadows are a no-no. Does that mean you never use lights on both sides?

I'll try a wider arc this weekend. Thanks for all the help. This forum has been wonderful for me.

Jeff

Nah, it doesn't mean don't use a light on both sides.

When I shoot key+fill, I usually have the fill off camera axis on the opposite side of the main light. So if my main light is camera right, then the fill light is just to my left.

Unless the crossed shadows is what you're going for, the key light creates shadows, and the fill light fills them.

Feb 09, 2010 at 01:51 PM

Micky Bill
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p.1 #17 · White line on gray seamless

If you have lights of equal power, equal distance from the subject, you will have double shadows. One light needs to be more powerful to act as the Key light, then another light or a large white reflector on the other side to act as a fill. I prefer a large reflector, but it's up to you. Pretty soon, cgardner's spidey sense will kick in and he'll explain neutral fill.

Feb 09, 2010 at 06:10 PM

jwboring
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p.1 #18 · White line on gray seamless

Thanks Micky/Robert. The double shadows / main+fill is making sense to me.

Feb 09, 2010 at 06:25 PM

cgardner
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p.1 #19 · White line on gray seamless

jwboring wrote:

Hum, didn't notice that. I guess that is the result of lights on both sides

I guess double shadows are a no-no. Does that mean you never use lights on both sides?

If your goal is flattering lighting a better strategy for a full face pose is a centered pattern with key light directly above the camera and fill slightly below.

When putting a key light to the side for short lighting if you place the fill over the camera it will illuminate everything the camera sees evenly, producing a foundation which lifts all the shadows without any void.

When setting lights set the fill first before the key light. Observe where it creates shadows. Understand that if the fill is creating a shadow you will either wind up with a dark void in that area or if the key light overlaps it a highlight which is darker than those where both key and fill overlap.

Click the WWW button below and read my tutorials to better understand the cause and effect of key and fill and how they need to interact to create smooth even shadows.

Your line in the seamless is a result of the way it is hanging an the light is hitting it. The light area is catching the reflecting the light but the areas above and below it aren't making the contrast obvious.

If you try the centered strategy suggested above both lights will be oriented towards the background and you will find it will be illuminated more evenly.

Feb 09, 2010 at 06:46 PM

dougstroud
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p.1 #20 · White line on gray seamless

Tagged for reference

Feb 11, 2010 at 01:32 PM

E-Vener
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p.1 #21 · White line on gray seamless

you need to light your background either from above or more from the sides to eliminate that brighter reflection at the curve. it is the old angle of incidence = angle of reflection rule at work + where the brighter line is the reflection of your lights on the paper. Changing the position ofthe lights will change the angle of reflection, so play with where you are placing your lights.

Re : White balance: you say you are usign a gray card for White balancing, that is the right idea, but which card are you using and are you sure it is at a non-glare angle re: lights and camera?

Finally the Flash WB settign on any camera doesn't take into account either the specific flash or modifier you are using. The short solution to this is to do a custom WB in camera if you wantto continue shooting JPEGs or better start shootign and learn how to process your raw files, whioch is neither difficult or time comsuming. And of course , work on independently calibrated and profiled display using a tool like a Datacolor Spyder 3 Elite or X-rite i1 Display 2.

Feb 11, 2010 at 04:04 PM

jwboring
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p.1 #22 · White line on gray seamless

Thanks for the help E-Vener. I was shooting both raw & jpegs on that day. The jpegs out of the camera were just for ease of review by a bunch of other folks. Raw post processing would begin after the images were narrowed a bit. Due to all of the issues with the lighting, that number will most likely be close to zero

Lesson learned, don't post any non-wb-adjusted shots anymore

Jeff

Feb 11, 2010 at 08:35 PM

RobertLynn
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p.1 #23 · White line on gray seamless

Hurry and post a new one! I'm anxious to see if you got it sorted out

Feb 12, 2010 at 05:07 AM

jwboring
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p.1 #24 · White line on gray seamless

RobertLynn wrote:
Hurry and post a new one! I'm anxious to see if you got it sorted out

I'm truly a weekend warrior because my day job has me away from my family & studio during the week. I'll try to shoot with the wider arc this weekend.

Jeff

Feb 12, 2010 at 01:37 PM

jwboring
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p.1 #25 · White line on gray seamless

Results of the reshoot:

1st pic: 1 light set up, you can see the white line on the seamleas
2nd pic: Close up of the seamless with original tiny arc
3rd pic: Results with the original tiny arc. Still shows white line.

2012 © jwboring

Edited on Feb 14, 2010 at 06:14 PM · View previous versions

Feb 14, 2010 at 01:29 AM


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