Important Demo - Light Sources (Halogen vs. Sun Gun)

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imported_Dave KG

New member
A question often asked is what light sources are best for highlighting swirls, and there are a great many on the market which offer that ability. A popular choice is the 500W halogen light readily available from B&Q, Screwfix etc and as the photograph below highlights they are very good at highlighting swirl marks:



2009_0310WagonR0006.jpg




And also good at RDS:



2009_0310WagonR0011.jpg






However, 500W halogen lights are not completely flawless, and do have quite notable limitations when it comes to spotting lighter marring, especially hologramming left by a rotary polisher. The example below clearly highlights this.



Below is a picture of the paint finish taken using 500W halogens to assess:



2009_0310WagonR0050.jpg




The finish looks perfect! Good clarity evident. No sign of any marring. The truth of this finish is quite different however, as the Sun Gun highlights on the same area:



2009_0310WagonR0051.jpg




Very definite hologramming! And this was not evident using the halogen lights... The Sun Gun is a very reliable source of light for assessing paintwork at all angles, the 500W halogens hid these holograms at all angles of viewing and only with very careful movement of the light source and examining the finish very closely was any evidence of the marring picked up!



So if you are using 500W halogens as your sole light source, be very careful of what they can hide!





As a further example, here's the finish on the car examined with the 500W halogens both before and after the hologram removal:



2009_0310WagonR0050.jpg




2009_0310WagonR0054.jpg




No real difference at all is apparent! The Sun Gun Clearly shows that a difference has been achieved:



2009_0310WagonR0051.jpg




2009_0310WagonR0058.jpg




2009_0310WagonR0060.jpg






I know the Sun Gun is expensive, but I would strongly consider a bright light source with small area of some description for swirl spotting... Part of the halogens issue is the large light area (bright region). I find that a camera flash is very effective at highlighting hologramming - not practical, but will certainly give more confidence in the finish than 500W halogens will IMO.



Food for thought.
 
What kind of light is the sun gun? Xenon? Flouresent?



I'm thinking of purchasing the Brinkmann Dual Xenon Max Fire spotlight
 
Dave KG- I always enjoy your posts, even when my experiences don't parallel yours (which is really only with regard to the SunGun ;) ). Your pics and write up are simply superb.



I fully agree that the SunGun beats halogens for meticulous inspection. I still can't see *faint* holograms under mine, but I'm starting to think that's a matter of my vision more than anything else. For the kind of holograms in your pics (which I'd consider moderate or even severe, maybe I'm not as awful with the rotary as I think I am :D ), yeah, the SunGun works well.



Maybe you and I just have different opinions regarding the severity of the holograms in question, maybe we're actually closer to agreement on the SunGun that I'd thought :think:



If you ever get a chance to try out incandescent lights (for light marring as opposed to holograms), I'd be very interested in your findings. I still like those the best but hey, that's just me.



Anyhow, thanks for posting this and for letting me babble on your thread, I really *do* enjoy your take on this subject.
 
Wow very nice. I really enjoy your posts. Its amazing what different lighting

sources can do. Now if the rest of us could just afford a sun gun... :D



Great job
 
Thanks for the post Dave! :2thumbs:



How does the Sun Gun compare to the Brinkmann? I currently use both halogen and the Brinkmann.
 
What is the comparison to 1500 watt halogens? I have dual 1500 watt heads on my set up. I tend to think it shows things up quite nicely but after reading this I find myself double thinking that. I know you only used 500 watts so I still might be good. But if it's halogens in general I might have to look into anothe light source.
 
Great write up Dave!



Your right, when it comes to true inspection for "paint correction", halogens should never be used. Either a Sungun or brinkmann should be used. I sometimes will use by flash off of my camera and snap pics for inspection.
 
If it is just the need of a concentrated light source. For those that are cheap, I'm sure you could make your own concentrated light source using an HID kit, some cheapo projector driving lights and a computer PSU.



$60-$80 for HID kit, 20-30 for projector driving light, $10 for cheapie PSU + a quick fabrication for a handle (? cost should be cheap).
 
My camera flash seems to show all. Oily LSP's like NXT look good until you hit it with the flash.
 
I always try to use the sun for my final hologram check because as you showed, hologens aren't good at picking them up. Nice to see picture proof to know I am not the only one who has noticed this. :)
 
Yeah I have started using the Fenix LED flashlight and it's really quite good at picking up things like this, but yeah I always do a final inspection in the sun.
 
I tend to lean towards that; it is more so the angles of the light, than the light type itself. The reason that I have come to this conclusion is that on vertical panels, I have no problem seeing holograms with the halogen lights. Usually on horizontal panels, holograms do not show up as easily.



I think that it is the packaging of each light that limits its ability to show holograms more that the light type itself. With the Sun Gun, Brinkmann, or CM5300 (which are all exceptional lights for doing final inspections) you are easily able to change the angle of the lighting; with a halogen however, you are somewhat restricted because of its bulky packaging. If however you could raise the halogen lights high above the panel (at the right angle) I think that the result would be pretty much similar because you are essentially narrowing the beam of light as you are raising it higher.



Again this is just my opinion on the subject. So while I agree that every detailer would be doing a grave injustice to themselves by not using one of the lights above (Sun Gun, Brinkmann, or CM5300) for final inspection, I do think that it the angle of the lighting that shows the holograms more than the type of lighting.



While I always love your post, I just do not have 100% “buy in� on this one. In the end it may just all be a matter of semantics.
 
howarb said:
In the end it may just all be a matter of semantics...
Click to expand...



Yeah, I think there are a whole lotta different things that could explain differing experiences. I do find it an interesting topic for discussion though, more so than "which LSP for [some color]".



A while back the other PC posted some good info about lighting where he explained how/why "point source illumination" is so good for final inspections.



More of my rambling on this whole thing (specifically hologram-spotting) follows:



When it comes to spotting holograms, I bet a lot of it depends on how serious the holograms are. I've posted before about the tricky *very faint* ones on my Yukon- it took two people, working in sunlight at *just the right time of day* to spot them; they were so faint as to be simply invisible 99% of the time and would only show up when the panel transitioned from partial shade to full sun (again, with both the sun and the viewing angle *just* right). One person moved between the sun and the panels to provide the transition while the other person looked for the holograms. It'd take about four-six tries to spot 'em that way.



I must've spent half an hour trying to spot those with my SunGun, and that's after I knew where they were! No way. By the time I finished messing around with that the sun had moved and I couldn't spot 'em (back outside) again until the next day. These simply drove me nuts until I finally got 'em corrected (and for some reason I had to get really aggressive too).



Now the holograms I got on the M3 were different; I could spot the nastiest ones (from when I used 3M PI-III ECRC) with incandescents and the rest of them with the SunGun, it worked fine on those. But those aren't the kind of holograms I'm usually worried about; once I'd satisfied my curiosity I switched to my regular techniques where I removed >90% of them without even bothering to inspect. The faint ones that were left (uhm...I mean "are still left", this project is taking forever as I seldom work on it) are pretty hard to spot with the SunGun and I'm not sure I could find them all that way, sorta doubt it.
 
howareb said:
I think that it is the packaging of each light that limits its ability to show holograms more that the light type itself. With the Sun Gun, Brinkmann, or CM5300 (which are all exceptional lights for doing final inspections) you are easily able to change the angle of the lighting; with a halogen however, you are somewhat restricted because of its bulky packaging. If however you could raise the halogen lights high above the panel (at the right angle) I think that the result would be pretty much similar because you are essentially narrowing the beam of light as you are raising it higher.
Click to expand...



I disagree. Having smaller halogens like this allows you to move the light any way you want. I still can't detect them as well with halogens as you can with different light sources. I always rely on the sun though.
 
blk45 said:
I disagree. Having smaller halogens like this allows you to move the light any way you want. I still can't detect them as well with halogens as you can with different light sources. I always rely on the sun though.
Click to expand...



I am glad that you disagree, because it would not be as interesting of a discussion unless you have both sides of the story :).



The sun for me is a very unreliable source, mainly because I have no control over it :D . I am not saying that the other lights are not better at locating certain flaws, but the halogens are not useless and can also show the same flaws when angled correctly.



Accumulator's last post gives a great example of the sun as a light source, even requiring an angle (and type of holograms). Recently I completed a White Mercedes with just using halogen lighting and I could see micro-marring just as clear as day on the vertical panels.



There are so many other variables that can play into this as well, such as light distribution, color, and lumens, however one can not negate the power of angle.
 
I can spot swirls pretty easily with my fenix L2d. It's a pretty focused hotspot and very bright 180 lumen LED flashlight. I haven't compared it to the sun yet though to see if it can't spot something the sun could.
 
I think part of your problem with the pictures you took under the halogen is that you allowed your camera to focus in on the wire mesh on the reflection of the halogen lights. This will effectively pull out of focus any minor surface defects. It's possible with proper focus, that the same defects would have showed on the halogens as did with the other lighting.
 
I wonder would a hand held incandescent work light with a 5500-6500k bulb work just as well as a sun gun, or Brinkman's light?



5500-6500k is considered daylight (sun +sky) on the color temp scale.
 
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