Reflections in Light Tent

Hi all,
I am attempting to shoot this vase in a light tent but can't get rid of reflections.
First time trying this... searched for answers and found 1 post saying don't use tent.
I would like to achieve minimal reflections but keep the tent for diffusion.
Thanks in advance to everyone.

I am using a large Photo-flex Literoom.
Canon 10D on tripod with 17-40L. (Exif attached).
My light setup is a 580ex as a master and a 550ex as slave.
Using Photoflex Q39 extra small light boxes.
Tried diffusion panels over the soft boxes and a circular polarizer.
The reflection of the lens is so apparent...I'm stumped.
Thanks.
Mac


File name: CRW_2296.jpg

Camera make: Canon
Camera model: Canon EOS 10D
Date/Time: 2007-01-03T00:23:24
Exposure Program: Manual
Flash used: Yes
Focal length: 33.0mm
Exposure time: 0.0080 s (1/125)
Aperture: f/6.7
ISO equiv.: 100
Metering Mode: Matrix
Canon 17-40mm f/4L

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Point your main flash stright up add a slave on each side of tent

Thanks Jack12,
I forgot to mention I used an ST-E2 on the hotshoe and the two speedlights
you can see in the reflection at maybe 20º from camera. I will try moving these to the side and add a third light bounced from ceiling.
Thanks again.

Light tents are over rated...they work well for some subjects and poorly for others! In shooting glassware and reflective (shiny) objects, the best way to do it often is a darkened room with SELECTIVE used of white panels or softboxes to highlight certain edges, etc. You PLACE reflections, rather than worry about removing reflections!

Dear Mac:
The object you are trying to photograph is not difficult but you have to address several issues first of which is to make a decision as to what the background is going to be. You have it sitting on white with what looks like black seamless or similar behind it with a wood floor showing inbetween. I don’t think this is what you want... is it?

Ok, to expand on some of what Wilt said, this type of image should be lit with large panels in a dark camera room. Of course your camera room should normally be lit only by your modeling lights anyway so you have control and can see what you are lighting and also what you are not lighting.

You didn’t provide any clues as to the size of the object so I will guess that it’s less than 2 feet tall. Once the setting has been decided on, it is easily lit by using a large diffusion panel 90 degrees to one side of the object and a duplicate panel or large white reflector in the same location on the opposite side of the object. Using a panel on one side with a reflector on the other will give you a more dominant specular highlight on one side than the other. This image being symetrical, I would prefer both light sources bring precisely the same.

You must remember that to control specular density, you need to work with your panels very close to the object. The futher away they are, the brighter the specular highlights will be defeting the purpose for using them in the first place. Diffusion panels give you control over the size of the light source by adjusting the distance from light source to the panel. This is a classic case where we want the light source back far enough to fully cover the entire surface area of the panel for a totally consistant and very large surface.

This object has a very high surface efficnency so everthing else around it must be very dark and not lit by your light sources. That would include you and the camera and tripod. This is much like photographing a mirror looking directly at it. You and your hardware must be there but not seen so you have to remain in the dark. I would photograph this object with the camera no closer than 10 to 12 feet using a long lens as you would with a portrait. I would also cover the tripod with black fabric and see to it that there were no other light color items within the objeccts field of view.

Now to analyze how the two panels will properly light this object we have to viaualize where they will be seen in the object as specular reflections. The panel on the right will present a long specular highlight for most of the height of the object. It will also paint specular highlights on the handles. These highlights will be on the outsides of the handles facing the panels and also on the insides of the handles on the opposite side giving adequate separation. Depending on what background you select, it may also be desirable to provide some separation directly over the object to add specular highlights on the tops of the handles and also the top rim of the object. This is easily done by simply placing a large white board on top of the two panels directly over the object. The 2 main panels will provide light for the top reflector. Keep the object far enough from the background so that the background remains soft and is not significantly lit by the light sources. Use barn doors on the flash units to keep the light centered on the panels and away from the rest of the room. I used your image to create a diagram of how you would set this up.

Metering would be quite simple taking one reading facing each panel from the center over the object to achieve identical f stop measurements. If desired, you could easily place a third light below the table top facing perpendicular to the background to add just enough light onto the background to place a gentle glow around the object.

I hope you like the background I selected and I hope you find this helpful.
Best wishes,

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To build upon Scott's message...
You can alter the placement and the size of the reflections with both angle of the light source (closer/farther from the camera) as well as the relative height vs. width. With a softbox you can mask off some of the softbox, for example taking a 24x36" box and making it appear to be a 6x36" strip. Using this technique, you can more effectively place the light to give the viewer a sense of form in the subject, with the trailing edges of the object falling off into darker tones, rather than being brightly lit as the example shows.

Nice example, Scott!

Or, you could use one light at the side & the spill from it could bounce off a white/gray card on the other side & mask it off as Wilt suggests.
When you have some time, look through these: FAQ - Studio Lighting

HI Wilt
I appreciate you ideas to Mac10 but with great respect, I must explain why I disagree with your suggestion about stripping off a soft box down to a 6 inch width. I certainly mean no offense at all but I feel I have to try and clarify things a bit to avoid confusion to other readers.

Ok, first, yes of course you can change where the specular highlights appear in the surface of the object by changing the placement and size of the light sources. You suggested masking off a 24 X 36 inch soft box down to only 6 inches wide by 36 inches long. The panels I had in mind are 7 feet tall and over 3 feet wide. Considerably larger for very good reason. A shape like this vase is like a wide angle lens. It “sees” all over the room so the only way to truly show the shape and form of the object is to use a large enough light source to be seen in a large area of it’s curvature and from fully to the side of the object to far enough around the front to illuminate the frontal surfaces.

You said that using this narrow strip light would give the viewer a sense of form and not be as “brightly lit” as the example in my diagram. Well, first let me say that I don’t think anyone would assume than the brightness level of the specular highlights in the vase seen in my diagram are supposed to represent the actual way it will look. I simply painted them in quickly to demonstrate a very rough idea of where they would appear and what they would approximately look like. In reality, using the large light sources very close will insure that the specular highlights are very low as they should be.

The problem with the skinny strip light is that when you reduce the amount of surface area of your soft box, you reduce the amount of light falling on the subject. It is now necessary to open up your lens to maintain proper exposure. The specular brightness level of course remains the same so as soon as you compensate for the reduced light on the diffused highlight, you now overexpose the specular highlights making them brighter rather than darker as you suggest. This is just the laws of physics.

In addition, when using a skinny strip like that, it’s important to remember that this vase works like a wide angle lens so that 6 inch wide strip will look like a little narrow stripe down each side of the vase. In addition, because of the very limited width of the strip, it will not be wide enough to fully light the vase from the side where separation is needed and ALSO reach around to the very front of the vase leaving the front essentially unlit and dark. If you position your strip far enough forward to light the front and the sides no longer reflect the light source as they need to for proper separation from the background. This is a fat, round vase. A skinny vertical strip of light will just not work effectively.

Very sorry and again, no offense is intended but large, light sources are the correct way to light this vase to show shape and form AND keep specular density very low while properly illuminating the entire surface of the object.

The physics are just this. The larger the light source and closer it is, the darker the specular highlight will be relative to the diffused highlight. So much so that you can actually fill a pair of reading glasses completely with specular highlights that are so dark that you can see right through them and observe the color of the eyes behind them. Move the light source away, and you have small, bright chunks of reflected light that are undesirable.

Backing the light up and/or making it smaller will only accomplish making the specular highlights brighter and they will appear as thin stripes. In addition they will provide almost no significant specular highlights on the small, black handles to separate them from the background.

I have photographed objects like this many times over the years and small light sources will not give the necessary control. By working with a light source that is 36 to 40 inches wide and perhaps 4 feet or more above the table top, you have the ability to create beautiful, controlled specular highlights and light the object properly at the same time.

Once again, I respect you and usually agree with what you say so I hope there are no hard feelings. OH, and just for the record, I fully agree with you that most light tents are over rated.
Best wishes,

thanks for the example. great tip.

More excellent points, but...

I'd agree that it's one best way to light it, but can't help pointing out that it's not the only way to do it?

7' light boxes are great if you have them, but sometimes you can substitute a white wall to get a similar effect. The advantage being that most people have easy access to them, & I resist telling new people that, "You can't do that because you don't have this"? Lets not lose the fun in the learning process?

another take on an interesting problem:

the curved shape of the vase means that the reflected view is 180 degrees. Any variation in light intensity will show up on the surface. To get featureless illumination, you need absolutely diffuse light. Even a seven foot softbox still has boundaries that will show up in the shot. The light source has to be uniform across the entire reflected field of view. That includes the front of the lighttent, which is not illuminated in the above solutions. I would shoot this in a light tent outdoors on a heavily overcast day.

In the photo you posted, it seems that the fabric of your light tent is too thin, and doesn't provide enough diffusion. that's why your flashes show up as discrete lights. Using room lights, bounced off a wall, with a long exposure, does a better job.

No matter what you do, the frame support of the light tent and the camera itself will show up in your final photo.

Again, nit-picking, but I might prefer to have one area of the reflection in the vase hotter with the light feathering off to the edges.

lightingman wrote in post #2501746
HI Wilt
I appreciate you ideas to Mac10 but with great respect, I must explain why I disagree with your suggestion about stripping off a soft box down to a 6 inch width. I certainly mean no offense at all but I feel I have to try and clarify things a bit to avoid confusion to other readers.

There are lights placed to illuminate the subject, and there are lights placed to accent certain key features of the subject. I am talking about the latter. I have done commercial photogrphy of glassware, and know about what I speak!

I used a 5x36 strip merely as an example of masking down a larger light source to achieve the accenting which complements the subject in a different way, not as a rule....it could just as easily been a 18x36 strip.

And sometimes we accent the edge, not a facet of an object, to give it form against a dark backround.

Here is an example (scanned from an 8x10 Ilfochrome print) of placement and size of the light source accenting the shape of the subject (bottle and glass) in a workshop photo taken many years ago. The exposure was actually THREE exposures on one piece of 4x5 film, made in camera and not with darkroom or Photoshop wizardry...one for the shape of the bottle/glass, one for the wine inside the glass, one for the background. The overall lighting certainly can be worked on to delineate the edges of the bottle better in the shadow area to separate it from the set, but the point of the strip light was masking it to best portray the glass and bottle. We were working on accenting with selective light placement, not on overall exposure, and all the items were props which I had brought for my exercise. So some set design was included but it was mostly lighting the product, and I had four hours to compose the set, light it, and make the shot...a real world commercial photography kind of situation. In this example, a 36x48" softbox was masked to a narrower strip. Believe me that it was NOT as effective with the softbox at the full size, it was far more effective as the narrowner strip. Had this been a real product shoot, I probably would have added a source to set right, to delineate the edge of the bottle better.

I LOVE this thread!
And I'm going to put a link to it in the "Lighting" Sticky, FAQ - Studio Lighting, so being bored & having nothing better to do, I'd like to make a couple of slightly OT points.

My 10-minute effort with a similar subject:
Pic #1. If I had a choice of background, I might pick a lighter one to save myself some of the headaches you're having. The lighter BG provides a smoother transition for the highlights.

Pic #2. If I had a choice of angle, I would pick a highter one in this case to save myself some more headaches. See how a lot of the problems just go away? Nothing else was changed except the tripod height. (Except that, looking at it, I may have made the cup a touch darker before conversion from RAW).

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Pic #3. A shot of the set-up. One light. With 2 you can do SO much more!

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