Aluminum

[Elliot]

Hello,

 

Does anybody has experience photographing aluminum...? I am having a lot of problems focusing a cabinet that has round edges and it is made out of aluminum. I have tried everything possible and the photographs look too fuzzy. The only thing I have not done up to now is "flagging".

 

Thanks

Elliot

[bokkins]

try to use a tripod and turn off the flash, put a picture that the aluminun can reflect just like what we do on 3d.

[Elliot]

Neil,

 

Tanks for your response. I will try your suggestion.

 

Thanks

Elliot

[William Alexander]

Polished, Brushed or Mill Aluminum? Are you/can you do work in PS on the photos?

 

Aluminum, in particular brushed always looks fuzzy. The specular and reflections (mostly colored influence) seems to be extreme on the diffusion side. See attachement.

 

If it's brushed there are some things you could try when taking the photo- then tweaking in PS. Could you post up a reference image...might help get to the specifics

 

WDA

[Elliot]

William,

 

Thanks for your response and comments. You put me to think about the problem I have. After listening to you I am more deeply convinced that I have to trick the camera into not seeing the light coming from different angles. Last night I read a site suggesting that a foam board is placed between the camera and the subject. Then drill a small hole through which to let the lens look at the subject.

 

 

Upon examining your example photo with your posting I can see that the blooming you have is different than the problem I am experiencing. The problem I have is that the corners of my subject look very fuzzy. My camera has been tested for back focus and it is OK.

 

 

I am attaching two samples cropped at nearly 100%. These samples where taken from a sturdy tripod, the camera on remote control, at 1/250 Seconds and 19F. Different lenses where tried. The attached samples were taken with the 60mm F/2.8 D from Nikon. I used 8 Flashes slaved to the camera via Infra red. The flashes where not aimed directly over the subject. They were either placed behind a diffuser or shooting through an umbrella. These flashes (Nikon SB-800's) where used as fill light. I waited for a morning beautiful sunlight. Placed the subject in the garage facing outside and used the flashes as fill light.

I am attaching the samples with the problem. I am also attaching a photo of my daughter's bike. The bike seems to be sharp enough but the aluminum edges on the cabinet are fuzzy. I have some experience with shooting jewelry. I used a large softbox and reduce the blooming effect in that way. With the cabinets (24" Wide x 6" Deep x 72" Tall) I have tried through diffusers and umbrellas to reproduce the softbox effect used with the jewelry.

 

 

This problem has me confused. Your explanation of the effect is very similar to what I think. However, how do I make it work? I want the camera to produce a nearly perfect picture requiring minimum amount of post - processing. Right now I have to do too much post processing. Take a look at the cropped close up section of the bike. It looks acceptable. Why the aluminum is not showing up in a similar way...?

 

 

Question - One of the senior guys at the camera forum. (The camera forums users are very direct with their comments unlike the general politeness of CGA) This senior guy commented that this thing I was trying to achieve is an oxymoron because there is no way to make a round edge look sharp. I disagree with this explanation. It may be a round edge will increase the effects of Depth of Field. On a shallow DOF lenses like the 60mm I used, this could cause the edges to be out of focus. However, take a look at this links:

 

 

http://www.dofmaster.com/dofjs.html

http://www.dofmaster.com/doftable.html

http://www.sweeting.org/mark/lenses/nikon.php

 

 

I think what I am trying to do is within the technical bounds of the lenses. I think there is a reflection issue with the light coming out of the aluminum. A professional friend photographer thinks that is has something to do with the light entering through the Bayer filter grid and how is it hitting the CCD sensor. He thinks this is a technology limitation that could probably be solved with a full sensor Canon where this problem is not so pronounced as on a small sensor.

 

 

Thanks once again for your help and comments. You are one of two people that understood the problem I was trying to describe. I was at the camera forums. These guys there are not as good as the people on this forum. Our CGA people really know how to paint pixels with light.

 

 

Thanks

Elliot

[William Alexander]

Elliot,

 

Been giving this some thought.......

 

1. Try the lowest, most diffuse light level you can get a good response from your CCD. Did a test run on the pipe reference piece, 100 watt bulb, a piece of paper over it Basically to kill the extreme spec. Took the staight jpg into PS converted to lab and levels adjusted the lightness channel (yuv thinking) until the spec and general brightness was to 'par'. A fairly wide margin of adjustment. My camera is rather old and unrepsonsive CCD at low lightlevels. One thing to try. Maybe even try taking pictures outside, darker cloudy day when the light levels are at thier most even. Inverse of nuclear lighting and nanosecend exposure-similar results, even lighting.

 

 

2. Another, the images I have specifically ***250.jpg (The two wall panel units in one image) .... do a levels adjustment-per channel rgb. Bring the left hand slider up past the first hump of the histogram to about the trough, for all three channels. They are not symmetrical per channel but have relative humps. This will really tighten up the channel contrast and 'vividness' (if thats a word) LOL. Then use the shadow highlights adjustment Image>Adjustment>ShadowHightlight. At the bottom of the shadow highlights window- take the mid level contrast down 15-20%-make sure the layer the image is on is selected

 

3. "Composition" That artsy stuff kind of composition. Vary up the light intensities, colors (temp). This might be a case perfect symmetry in your lighting is killing the beauty of the metal. Most rooms these units will be in haveexterior windows, and a range of lights being used. Basically a number of color temps, sun, sky, flouresent, incandesant and halogen. Metal looks crappy in 3D without refelctions and the color of the lighting 'reflecting' (term used very loosely) in/on the metal....so may go real world photography emulating bad 3D LOL.

Try using warm fill lighting on one side, cold fill lighting on the other and a key light that won't over power the color temp infulence of the fills. Another option might be just doing a gradient layer in PS (orange to blue), softlight and tweak the opacity/fill back until you like the looks. There is actually quite a bit of variance in the pixels that appear to be washed out/blurring. Meaning that the softlight will will amplify-bring those variantions out. Maybe ever so slightly but maybe enough. The variation of the lighting may help visually express that it is metal and in a more creative "composition". Guess at the heart of the 'macro' matter shiny things describe thier environment, no envirnmental variations=our minds can't really get a grasp on what kind of material it is, from a visual standpoint and looks wierd

 

WDA

[Elliot]

William,

 

Wao....!!! You have really impressed me with the comments. Your observations are very significant. I am up to my ears with this mechanical drawing I have to turn in by next monday (about 20 pages).However, I am going to take a break and try your suggestions.

 

I am not too sure I understand your explanations on the channels. Your are too advanced on Photoshop. I am just bellow average. Specially when it comes to the channels, a subject I am not very well versed. I remember from other threads that you have a very deep knowledge on CS2 - Photoshop. Now you have encouraged me to read more about these issues.

 

This product photo is very important for the literature project I am doing. Probably I will be up north in about two weeks. I will give you a call.

 

William.... I really appreciate your comments and the time you took for our phone conversation.

 

Sincerely

Elliot

[Jape]

hmm maybe the easiest solution is using a polarizer filter on your lens. A polarizer eliminates reflection by eliminating lightrays that are unpolarized and where the waves move in random direction. Usually this type of filters is used for eliminating reflections in glass, water and even for saturating the sky more, on bare metal is usually doesnt work depending on the type of metal. With aliminium i honestly wouldnt know for sure how it will behave when using a polarizer filter. If you try, make sure you get a circulair polarizer as a linear one will mess up the TTL and AF functions on youre (i assume) digital camera. Also hold in mind that a filter reduces the exposure by 1.5 stops so you need to compensate for that.

 

Grtz Jape,

 

ive looked it up and it seems indeed that a polarizer is very suitable for aluminium. quote from a polarizer manufacturer site:

 

Even reflections on aluminum house fronts are also polarized and so can be influenced by a polarizing filter, because aluminum forms a non-conductive surface layer of aluminum oxide when it has been anodized for a better resistance and a layer of aluminum oxide and aluminum carbonate in air as an environmental process.

[Elliot]

Jape,

 

 

Thanks for your response. This is the most perplexing thing I have ever seen. Everything else on the scene looks sharp except the round edges. I am starting to believe the comment made at Nikonian.org. There one of the senior guys told me that getting a round corner to look sharp is an imposible task.

 

I think is something to do with light. I already used a polarizer lens. The one I used is the Sunpack 77mm CPL Circular polarizing Lens CF-7063-CPL. On the instructions for the lens it actually mention my particular problem and is says that is one of the reason to use the filter. On the other lens I used the Sunpack 62 mm Circular Polarizing lens CF-7060-CPL. Neither lense solve the problem.

 

 

Tonight I worked with Dr. Russell Brown CS2 Merge scripts and I was able to decrease the problem. However, this is not the right solution.

 

 

The tech support person from where I purchased all my equipment is perplexed as well on all this issue. He is comming to my office with the store D2X, D200 and 5D. He is also bringing a Profoto 2400 watts per second strobe system. I have been working on my scenery, placing diffusers and flaging the lens. I even tried to do a model in Viz to test our theories.

 

We are just out of ideas....!

 

Thanks

Elliot