Let me elaborate on my earlier post - take an incident reading of the light falling on your subject (with the dome on your meter) - this becomes your exposure. Then take a reflective reading(with a spot meter or with the dome off if your meter can read reflective) off the background - when the backround reading is 2-1/2 stops reflective higher than your incident suject reading then the backround will be white. The reason you take a reflective reading off of the background instead of an incident reading is that an incident meter only measure the light falling on an object - so it is useless for predicting precise tonalities - the reflective meter measures the light being returned by the backround enabling you to predict the final tonality with precision. This technique allows you to create a white backround whether you are shooting against a white wall, a gray wall, a black wall or any tonality in between. The best teacher of lighting principles was the late Dean Collins and his finelight venture back in the mid 80's - lots of his videos are still available as well as some of his finelight printed matter - I would suggest these publications highly. Hope this helps.
Originally Posted by mark
I am going to describe the technique I use all day, every day, for lighting pure white backgrounds with MINIMAL blooming, edge fringing and very little lens flare. What follows is very simple, but does take a little work. This is a discussion of how I use this technique, largely with digital cameras, but the philosophy and technique is 100% identical to using film of any type.
I light small products daily and they have to be knocked out as close to 100% as possible in the camera. The tool I use the most, and what facilitates shooting products knocked out on white is called a shooting table. There are many types of shooting tables, made by a handful of different manufacturers, but the one I use is made by Manfrotto and sold by Bogen in the USA.
They have two different sizes, and I shoot on both. I shoot very small items like jewelry on the small one, and items like shoes, electronics, handbags, neckties, etc. on the larger size.
Here is a link to the Manfrotto site that shows the larger table:
Here is the smaller of the two:
The transluscent table is half of the battle. The other half is to light the product.
The idea is to turn the entire piece of plexiglass into one large light source. I place one strobe directly under the bottom of the table pointing upwards, with the broadest reflector possible (and also bare bulb works well). I also place two strobes in the back of the table about 1 1/2 feet apart. I angle them slightly towards the wall I have the table up against.
I cover the wall with silver photographic foil so that the light reflected off of the wall does not have a color bias. Even the whitest paint has whiteners and brighteners in it which will render blue (as others have mentioned).
It is very much like tuning an instrument to get the light from below and the light from behind to match in intensity. A spot meter would work well to make sure you are getting even coverage. A polaroid of the table exposure once you get close would also tell you how evenly you've lit it.
Now that you have the background lit, you can place your object on the table and light it. You will notice that lighting the object will also cause an increase in the brightness of the table, because you are bouncing light off of it as well as passing light through it now. You may find it necessary to back the lights down a bit that are lighting the table.
Like I said, this is almost exactly like tuning an instrument. Once you get the hang of it though, you will be able to create almost perfect knock-outs without using any digital post-production.
IF (and this is a big IF since this is the APUG site), you wanted to you could do your proofing with a digital camera. It would make the tuning process much quicker, and you would be able to then switch to film if you chose.
The system you have described here is exactly the same way we did it back in the 1950's. We still had to go with a mask to create the knock out in the stripping department. As I described before and was taken to task for it, it simply was not possible to eliminate the eroded edge of the subject. I believe that we were just as skillful in tuning light then as you are today! We
could get close, but not close unough. According to clients and the printing processes available at that time. The example shown that was supposed to exhibit a pure paper white ground was indeed nearly white, but the color image so distorted that it was totally unacceptable by professional standards. If the distorted in my mind near florescent unnatural greens and color are the results the photographer planed and wanted then I back away and say so be it. I will accept the image as a very poor illustration of technique and move on. Today with in the printing business there are many miracles that did not exsist when I was part of it.
My question now is why waste time to tune light, when you can shoot on blue screen, yellow screen, or green screen. Then knock out the ground to any color including white with a few punches on the computer. I was at ILM when the first StarWars movie and Battle Star Galactica
were released. Blue screen was king, with video and film and pretty much ruled the roost. Today with CGI (computer generated images) anything can be done with out hard models. A simple chromogenic ground and digital camera can do the same thing as our light tuning in a snap of the fingers.
Michael your post is a good one and the technique you describe are exactly as were used years ago and will get you close, but close back then was not good enough! a mechanical knock out was and in many cases still used today!
I am sure that I will again be chastised for my statements here, but I am standing by this and my earlier comments! L.F.B.
Then you should stand by them. Your experience rules supreme in your kingdom (no pun intended...well, ok, a little pun intended).
I shoot on white and not blue screen beause I am not familiar with blue screen technology and have not studied it enough to be comfortable using it in the studio.
What I do know though, is that the commercial shooting I do is all digital, and the lights I have tuned on my shooting table represent a pure white, or nearly pure white at tonal values of 253-255. When I have my shooting table tuned to be able to shoot in that matter, I do not feel that it is necessary to do any more mechanical stripping. I guess on film a pure white is different than in the digital realm where pure white is equal to no data. It is interesting to think of it that way, and it may explain the difference between a white background on film, which contains much data and information in the film, and the color white in the digital realm, which contains no data, or the R,G and B channels are at 0 (zero).
I do believe that your tuning skills back when you were shooting were superb. I didn't mean to imply that skills today are superior.
I know that when I light items the way I described, using the tools I described, I can get very crisp edges with little to no blooming.
On very rare occasions we will have the perfect product that needs little retouching, but in all cases the images are looked at in Photoshop, a highlight chosen, and any slight background tone is dodged out (not erased).
As for needing a mechanical knock-out, has that term been superceded by a digital knock-out? I haven't seen many pieces of ruby-lith lately (but have worked with it back in the days when I was shooting my own half-tones).
I don't think it is a waste of time to tune the light. I know that I shoot with other photographers who don't take the time to tune their lights, and it shows in their work.
I think the tendency to get sloppy and ignore basic fundamentals of lighting is very prevalent today with the miracles of technology. If you are sloppy with the very important task of lighting something, then your sloppiness will certainly carry through to other areas of your work.
The understanding of today's technology and the possibilities it creates is definitely enhanced when you have an understanding of the generation prior.
And as for being chastized or taken to task for your comments, heaven forbid! You have valid experience to share, and I'm glad you did.
Here's a semi-knock-out I did on Wednesday...
Shot on foam-cor with one light...but needed no retouching. The whites were white, and the shadows were hard. I got tired of knocking out EVERYTHING and so I shot a bunch of sunglasses like this. The shots were a hit, and now I've swayed those art directors in charge to think outside of knocking out every single shot.
My 2 cents..
Well, I'm part of the "yes it can" camp. For some years I photographed bottled products from wineries and distillers, all with plain white backgrounds, on b/w and colour trans.
Setup was : softbox to one side, white reflector fill other side, background lit by flash head from below.
Incident reading for subject, reflected reading to overexpose white background about 2-2.5 f.
Usually with 105 Makro-Planar on Hassy.
There was no budget for clear cutting or other afterwork : effect had to be achieved in camera.
It's like the bumblebee - aerodynamics declare it can't fly , but it does.
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
This will be my last post on this subject. it is obvious that you and others are satisfied with what you are getting, and have no desire to believe what other fine photographers have been very unsuccessful in doing. The photo of the sunglasses would have never been accepted for publication for several reasons, the most glaring is the horizontal shadow cast behind the light grey lens on the pair in the forground. The rear position or location is casting their shadow in a very confusing manor and would never get past an art director who knew his stuff. I am very pleased that you are enough satisfied with your results to display the example as what can be done. I am in no way knocking or saying you are wrong with your display print and comments but am simply saying that the folks I worked for and with would not have accepted the example as a product photo made to sell their products. Again, the facts!
I am happy that you and Smudger are happy with your results, but
I am somewhat disappointed by the "new" technologies and the results they deliver. Somewhere down the road I hope you and Smudger realize what I and others doing illustration work with film for over fifty years have commented on in this thread. Have a great time doing your thing!
I am outa here!
I don't want to bash with you regarding technique and what will 'pass' for any particular art director. In fact, this was what I said in a previous comment:
"And as for being chastized or taken to task for your comments, heaven forbid! You have valid experience to share, and I'm glad you did."
I won't debate you on what is good lighting, bad lighting, etc., just as in the other thread regarding the critic and what one critic may or may not like, it is the same with art directors and photographers. As I said in the previous comment too, this example I show is one that I am able to knock out the background to a pure white *and* leave a shadow. If it's something that you don't like, or don't think that any art directors would have signed off on, then your point of view and experiences are valid. I can't dispute that, nor do I want to.
I appreciated your comments in the other thread about giving your photographs voice or soul, and value those commonalities more than the differences we have regarding technique.
The equipment you recieved training on and used sucessfully in your career served you well and I congratulate you on that.
I hope you don't go away sour from this thread thining that I have come in to say that the way I do things is better or worse. I just came into the discussion to talk about a technique that has worked for me that I hadn't seen discussed in the thread previously.
Originally Posted by Charles Webb