White Background

[jamepc]

Hello,
I take pictures of products that I sell online but have an issue I just don't know how to correct. The items are placed on a white background inside a small cube "studio" with a light on each side. When I take a picture of a black object, the background is is perfectly white. However when I take a picture of a brass object, the background turns to a shade of gray. It's cast brass so it's not very shiny (if that matters). I use a Panasonic DMC-FZ28 on the Intelligent Auto setting, no flash. I'm not a photographer which is why I heavily rely on the Auto setting however I'd be happy to change any setting that will allow a white background to show properly. And if possible, how to change the setting too.
Thanks for any help!

 

[Rephargotohp]

Camera meters like to Meter to a middle Gray Object and when you have something other than that they try to make it gray. When the camera sees a lot fo white it will try to make it gray by under aexposing the shot That when you get your gray background with the brass part that doesn't have much effect n the exposure.


However when you put the black object in, the camera wants to make that gray and now ober exposes the shot making the background white/

I was hoping you camera had Exposure compensation,and it deosn't have a manual override like I would like but if youlook on page 88 of yourmanula, there is I.Exposure or intelegent exposure, This may help the situation when you have the brass piece in the scene. Try setting differnt levels of it to see if it helps.

If not the only thing else to do is to use manual exposure and try adjusting until you get a white background but not blowing out the image

 

[WesternGuy]

If possible, it would be nice if you could post an example of what you consider to be a "good" one and one that you are "not satisfied with". You might get more feed back. Also, a picture of your setup would also prove helpful. My first thoughts, from what you have said, is that it is the "Intelligent Auto" setting that is causing your problem - sometimes these settings are not so "intelligent".

Brightly lit backgrounds, like your white background can be anywhere from 1 - 2 stops brighter than 18% (medium) gray — which is what your built in camera meter expects to see. Therefore, when metering your cast brass with a large expanse of white the meter simply exposes it as medium gray giving you the gray background instead of a white one - automatic modes will do this. You meter is effectively over compensating for the amount of white in the overall image and underexposing your image. When you have a black object, depending on its size relative to the amount of background in the image, then everything is being exposed correctly. You may want to consider doing your photography using Aperture Priority and adjusting the exposure compensation by 1 or 2 stops to see if that gives you an image that is closer to what you are looking for. It is a bit difficult to give definitive advice, though, without seeing the details of your problem and what your setup is.

Alternatively, if you are capturing your images in raw format, as you can do with that camera, then you can alter the background in your post processing. How you would do that will depend on the software you have to edit your images. HTH.

Cheers,

WesternGuy

 

[jamepc]

Thank you for the replies.
Well I tried what seemed to be easiest which was to adjust the exposure. Adjusting it +1 to +1 1/3 brightened the background but also gave it a blue tint. Adjusting it max to +2 gave a nice whit background but the object was just too washed out.

Here's the picture of the dark object with a nice white background:
http://i1215.photobucket.com/albums/cc505/jamepc/Misc/P1060836.jpg

Here's the picture of a brass object with a grey background:
http://i1215.photobucket.com/albums/cc505/jamepc/Misc/P1060847.jpg

Here's the brass object with +1 1/3 exposure:
http://i1215.photobucket.com/albums/cc505/jamepc/Misc/P1060851.jpg

Here's the object with +2 exposure:
http://i1215.photobucket.com/albums/cc505/jamepc/Misc/P1060858.jpg

This is the setup I use:
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

Regarding the Intelligent Exposure, the manual says that it's one of the features already enabled when in Intelligent Auto mode.

Thanks again for any help.

 

[WesternGuy]

Well, I had a look at your images and I can see the dilemma that you have. A couple of things that I would try. First, try shooting in raw and see if you can get the colour back in post processing. The other thing that I would try is to cut down on the light for the lighter objects, maybe the light is overpowering the situation, i.e., the lighting that you use for the darker objects maybe too much for the brass objects - this may require a slightly longer exposure, don't know, but that is what I get from your images - it is possible to have too much light so that while you are getting the background okay at +2 EV, you are blowing out the object you are trying to get the image of by having too much light. Experiment with the lighting a bit, as not every object should require the same light and, if this works, then you may have to adjust the light for objects with different reflectivities or colour absorption - what ever the term is.

I also went and looked at some industrial photography sites (when I get interested in something, my curiosity gets the better of me :thumbup. I googled "industrial photography parts" and then added "tips" to the search and found these, among others:

Industrial Photography

How to Photograph Small Industrial Parts | eHow.com

The other thing that comes to mind, is that what you are trying to do is very similar to "jewellery" photography - I said similar, not the same - so maybe there are some hints to be learned from checking this subject out on the web.

Cheers,

WesternGuy

 

[bianni]

it is really hard to get pure white bg. you an shoot tice, one for bg and one for product or simply select the bg with magic wand and fine tune with quick mask and adjust to make4 it white

 

[bazooka]

You need to put that camera on manual exposure and manual white balance. Change your exposure so you have a nice white background like in #1 that is just short of clipping, and create a custom white balance and just leave everything like that. So no matter what you shoot, the background and color will not change. It will become a set-it-and-forget-it setup.