What exactly is depth?

**Todd@RUPES** · 03-12-2009, 10:07 AM

I have seen several questions recently on what is `depth` as it relates to the appearance of a paint`s finish. We hear the term frequently, "This wax has great depth" or "wow the paint looks deep!". As it relates to car finishes depth is an often misunderstood and misused term.

As it relates to car care, depth is the difference between the distance of an object (how far away it is) and the how far away it appears (how far away it looks). It is an illusion. A better example is a pool of water. If the pool is 5 feet deep and you place a quarter at the bottom it will look much further then 5 feet away. Light waves distort in the water and it creates the illusion of depth.

A camera lens on a DSLR is loosely similar to how an eye focuses. To illustrate depth visual I have taken two pictures from very similar angles on the hood of my car. Since the reflection of the car is taking place on the surface (or slightly below) I should get maximum clarity when I focus on the surface of the paint (assuming there is no distortion). However this is not the case because of the excellent `depth` of the Blackfire Wet Ice over Fire combination I used.

You will notice that when I focus on the blue painters tape, the reflections look slightly blurred (even though they are roughly the same distance physically). However when I focus on the reflections (making them sharper) the blue painters tape (which represents the actual physical surface distance of the hood) becomes blurred. The camera is even seeing a difference in distance that doesn`t exist. The reflections are `further way` or `deeper`.

Surface of the paint is in focus (including tape and light dust which is sharp, the reflection appears further way or `deeper`)

Surface of the paint is out of focus but the reflections looks clear and sharp (dust is no longer visible and the tape is highly blurred. To the camera the tape and phyiscal surface is about 8 ft. apart)

Even the pictures do not tell the real story because a camera is a mechanical object that uses mirrors, sensors, and data which is set to read data. I used a standard lens at 35mm zoom with an F-stop of 8. I did not set the camera to pick up significant differences in distance. Also it should be noted that real depth is very hard to capture with a photograph because it is a three dimensional illusion and a photograph is two dimensional. If you look at the photograph of a car and the door handles and mirrors are sharp in reflection, but the reflections appear blurry, then the car could have great depth. By the same token it could be very bad paint. Moving that thought one step further if you see a picture where the whole vehicle, including the surface, details, and reflections are sharp to could be that the paint doesn`t have a lot of depth. Alternatively it could be because the camera was shot with a high aperture, which pulls everything into focus.

By setting my camera on a fixed tripod and a test panel at a distance of 5 feet, I was able to test `focal` depth of different waxes and sealants. Certain waxes and sealants would require more focus depth (focusing further away, or deeper into the paint) and some required far less. By recording the focal points and then later testing the focal points against objects at various distances, I was able to at least have some forum of measurement of depth of various LSPs and waxes.

Given that the test panel never moved and was a distance of 5 feet, I simply subtracted the actual distance from the perceived distance to determine the depth of the reflection.

Bare Paint (natural depth): 3.5 ft
Autoglym Super Resin Polish: 5.5 ft
Blackfire Midnight Sun Carnauba wax: 8 ft
Blackfire Wet Diamond Sealant: 6.5 ft
Blackfire Ice over Fire Combo: 9 ft.
EinsZett Glanz Wax: 5.5 ft
Klasse All In One: 4.5 ft
Klasse Sealant Glaze (over Klasse All In One): 5.5 ft
Meguiars M21 V2: 6.5 ft
Meguiars M26 Hi Tech Yellow Wax: 7.5 ft
Menzerna FMJ: 6.5 ft
P21s Carnauba wax: 5.5 ft
P21s 100% Carnauba wax: 7 ft

Now in the end these are some of the waxes and sealants I have tested and far from the total amount tested (with some surprising results). Even though some of the numbers seem dramatic the actual visual differences, in person, where far less so. You eyes will comfortably shift focus with out much thought, which is why it is very hard to compare the depth of waxes and sealants by testing them side by side. Your eyes will simply focus on the difference depths with out much thought given to it. To test the depth of a wax (or too see visual differences) it is best to apply the wax to the entire panel and observe it from many different angles.

The base is that depth is an illusion and only one of the factors that determine the final appearance of the car`s paint. For best results, regardless of the wax or sealant chosen, proper paint preparation is key. Polishing the paint with a machine to remove damage, scratches, and paint blemishes will increase the gloss and appearance far more then any slight differences in waxes. Once the paint is prepared, waxes and sealants can be used to subtly tweak the effect, but again depth is one of the factors that some people enjoy. Others way prefer a brighter sealant, or a glossier wax.

I hope this clears up some confusion.

The

**SSTG** · 03-12-2009, 10:21 AM

Great info. Thanks Todd.

**D!Tailed** · 03-12-2009, 10:22 AM

Great info! Great article!

Thanks for sharing!!

D!

**imported_Termigator** · 03-12-2009, 08:25 PM

Gotta give props to M26. 7.5 ft. for $10! Would`ve loved to see how Souveran would have done.

**michakaveli** · 03-12-2009, 08:33 PM

Great post Todd, Thanks!

**imported_DetailDan** · 03-12-2009, 08:49 PM

Originally Posted by th0001

Bare Paint (natural depth): 3.5 ft

Sorry if I missed it, was this a polished panel?

**Todd@RUPES** · 03-12-2009, 11:48 PM

Originally Posted by DetailDan

Sorry if I missed it, was this a polished panel?

Lightly polished, but far from perfect. Light bends and distorts, hence natural depth.

Originally Posted by Termigator

Gotta give props to M26. 7.5 ft. for $10! Would`ve loved to see how Souveran would have done.

Souveran was 7.5 ft and Liquid Souveran was 6.5 feet. Poorboy World`s Nattys Blue and Red both posted the deepest reflections for a pure wax at 8.5 feet. Zymol Vintage came in at 6.5 feet, which was a little shocking. Again this is far from a scientifc test, just recorded observations in this circumstance.

**imported_DetailDan** · 03-12-2009, 11:53 PM

Originally Posted by th0001

Lightly polished, but far from perfect. Light bends and distorts, hence natural depth.

It would be interesting to compare a perfected panel to those numbers.

**Premium** · 03-13-2009, 07:52 PM

Nice info! Thanks Todd!

**imported_Termigator** · 03-13-2009, 08:36 PM

Originally Posted by th0001

Lightly polished, but far from perfect. Light bends and distorts, hence natural depth.

Souveran was 7.5 ft and Liquid Souveran was 6.5 feet. Poorboy World`s Nattys Blue and Red both posted the deepest reflections for a pure wax at 8.5 feet. Zymol Vintage came in at 6.5 feet, which was a little shocking. Again this is far from a scientifc test, just recorded observations in this circumstance.

Awesome! Thanks for the info. My life is now complete.