Reviewer's Note: The Quark Mini lights were provided for review by 4Sevens.com. Please see their website for more info.
Warning: Even more pic heavy than usual, due to the tint comparisons.
4Sevens has followed up on their initial run of Cool White tint Minis with limited runs of two new tints – Neutral White tint and Warm White tint. The Warm White tints are currently available for pre-order, and I believe the Neutral Whites will be following shortly. I also believe 4sevens is planning to offer these on their other Quark/Preon lines. Please check the 4sevens threads on CPFMP for more info.
I realize this causes some confusion, as most people commonly refer to the Neutral tint lights as “warm” – but that’s only because they are warmer than standard Cool white. The Warm tints presented here are considerably warmer than that – actually closely approaching incandescent.
To help you understand the difference between the tints I am talking about, CPF user DFiorentino has complied an excellent set of basic tint bin graphs:
Cree Cool: http://img30.imageshack.us/i/creexlampcwfull.jpg/
Cree Neutral-Warm: http://img170.imageshack.us/i/creexlampnwwfullix9.jpg/
To put things in a temperature context, premium WD-WC bin standard Cool White tints are typically in the ~5500-7000K range. By my eye, I would estimate the 4Sevens pre-release samples to be around tint code 4C/D for the Neutral White tints (i.e. ~4400K) and 7A/B for the Warm White (i.e. ~3200K). Please check for with 4Sevens for confirmation of what is actually shipping.
UPDATE: 4Sevens has provided more detail on the tint bins to be released for the upcoming Neutral/Warm lines, but I am not sure if they are exactly the same as the pre-release samples tested here.
FYI, the reason for reflected tint differences in the pics above is that more phosphor is typically used to get the warmer tints. This also explains the reported output bin differences - more phosphor also mean less luminus flux (the Cool White are R5s, the Neutral Whites are R4s, and the Warm Whites are Q5s). Effectively, warmer tints always mean lower output bins for the same manufacturing methods.
As I discussed in an earlier thread, this poses some problems for photography where one specific color reference white point is used. Commonly, we use our camera's "Sunlight" white balance for most beamshots (~5200K in the case of my Canon, which is about typical). While not bad for Cool White/Neutral White comparisons, this makes Warm White (and incandescents) look quite yellow-orange in comparison.
Below is an animated GIF of colorful objects taken under various conditions. The first shot is during the day in natural light, followed by the various Mini tints, plus a P60 incandescent - all done under the common "Sunlight" white balance.
Here are some outdoor shots, starting with the control shot in daylight:
Again, all of the above are done with a Sunlight white balance, which seems to favor Cool/Neutral white over Warm white.
But there is also another problem – the magenta–green axis is apparently not automatically compensated for with the default Sunlight white balance. While I can see this most noticeably in the Cool white pics (i.e. they look greener in the shots above than they are in fact in real life), even the Warm tint pics don’t quite right seem right (i.e. the pics are missing some magenta).
I thought a better way to proceed might be to choose a white balance that is intermediate to all three tints. While my camera doesn’t allow me to manually specify a white balance color temperature, I can do a custom white balance. This is done by setting the WB against a neutral background under your desired lighting source. In this case, by shining all 3 sample tints onto a uniform neutral grey background to generate the custom ”average” white balance.
First, the control daylight shot:
And now a comparison animated GIF of all the tints:
Here’s another example:
Frankly, I’m not sure this custom “average” white balance is much of an improvement over the Sunlight white balance per se (the Warm tints look even warmer? ). But it has helped remove the green-magenta shifting I had noticed previously (i.e. less yellow-green in all the shots). Believe it or not, that is actually an improvement.
Anyway you slice it, photography of these different tints is not a simple matter – no one white balance setting accurately captures what you eye sees. This is likely because our brains do their own “white balancing” depending on the source of light.
At the same time, you can’t go and change the white balance for each shot. At the extreme, if you successfully matched the white balance color temperature for each tint, they would also look exactly the same! And trying to balance the pics on my monitor/graphics card setup according to what my eye sees is meaningless – it will look different on another computer.
So, at the end of the day, it’s best to stick with one white balance (either Sunlight or the “average” I created above), and just try to objectively compare the differences. That’s why I included the P60 incan in the shots above – whatever you may think of the tints, it does help show how much the Warm tints look like an incan.
Subjectively, I can tell you that I prefer the Cool and Neutral white tints for outdoor use. They appear to give me the closest to daylight color rendition. However, if you actually like the look of incandescents, then the Warm tints are the closet LED match you are likely to find.
For more info on my testing methods, please see my earlier Mini AA and Mini 123 review.
As you can see, my lightbox reads the Neutral tints as slightly lower output than the Cool Whites, and the Warm tints as considerably lower. Both of these are consistent with the reported output bins (R5 for the Cool, R4 for the Neutral, Q5 for the Warm).
As you can also see, runtime performance is comparable on all models. Note that runtime is heavily influenced by Vf, so I wouldn’t expect wide differences from one tint sample to another – all are likely made under similar manufacturing conditions. Again, the extra phosphor simply reduces relative output.
So, in the end, the only real issue you should use to decide on these various tints is just that – tint.
Hope the photo comparisons were helpful!