4Sevens Quark AA-Warm Comparison Review

[lak]

Thanks, Vincent and GunnarGG for your input.

warm white: same as incan but has just tried it a couple of times

Do you think the Preon WW could replace your Fortelux?

 

[was.lost.but.now.found]

Are you judging by eye in real life or by the palm photos?

If by the palm photos - then there is an explanation in order.

Yes I was judging by your photos. Your explanations make sense, thanks for taking the time to explain.

Everything I currently own is cool white, except for my neutral-ish TK40. The problem with making comparisons is also tint shift at different drive levels. My TK40 appears to get warmer at a lower drive level, but that's just what my eye sees. I know you mentioned you did not always use the same light level in some of the comparisons, so I wonder how much of a factor that can be as well?

 

[UnknownVT]

The problem with making comparisons is also tint shift at different drive levels.

The shift in tint at lower current drive levels toward warm/green is reasonably well known - the shift is far, far less than the difference between Cool, Neutral and Warm White LEDs - those would be quite gross differences compared to the shift due to drive current.

But the observation of tint shift due to drive level is a good one - not many notice that until it is pointed out.

In an coincidental/accidental way - the shift kind of follows the way we see ala the now oft referenced (by me ) of the Kruithof curve.

 

[ky70]

Do tell me please, why this matrix or the one posted in #23 (link) are any less useful than the triple beamshots?

In fact I will go as far to say the matrix is far more useful because we are looking at the same area, illuminated by the different flashlights, so can validly compare directly -
whereas the triple beamshots have different parts of the tree, and for example (and I did not do this deliberately) - it is kind of hard to differentiate and see the difference between the Neutral white and the Warm white in one of the triple beamshots.

I agree!! The single shots of all 3 illuminating (separately) the same area is what has me sold on the warm.

 

[GunnarGG]

Do you think the Preon WW could replace your Fortelux?

I don't know yet but I will see how it feels next week. I think regarding tint that it could replace the Fortelux and it is also good to have that extra brightness sometimes.
The wide beam/spill is a downside at work but I think that could be fixed.

Here is a pic showing the beam from Fortelux, ophtalmoscope and Quark mini 123 neutral white (Sorry, the ww Preon2 is at work)
Just to show the difference in beamprofile.

 

[EV_007]

Nicely done Vincent. Taking the time to answer and illustrate viewers request is very time consuming and admirable.

I'm really excited to see that LEDs are starting to perform like incans, although seeing a little green in the 9P beam kinda puzzles me.

Again accommodating various beamshot requests is greatly appreciated by us lurkers. Keep up the good work. 47s better let you keep the lights he sends you for your efforts. :thumbsup:

 

[UnknownVT]

I work as an ophtalmologist and got my preon 2 ww yesterday.
The light that has been in my pocket so far is this incan:
http://www.medisave.net/fortelux-n-diagnostic-penlights-silver-p-739.html

I mostly use my flashlight for looking at the conjunctiva or skin around the eyes. Sometimes mouth mucosa and other stuff.

I noticed that the ww Preon was a tiny bit on the cool side compared to the incan but that might be that it is a little brighter (on low) and maybe the batteries in the incan was a little old.

Many thanks for the invaluable input from a professional.

Looking at the specs of the Fortelux N Diagnostic Penlight both on the link you provided and on the Riester (Fortelux) own page on the light - they only say: "2.2 V vacuum lamp"
since it's driven by 2xAAA (=~3V) it is an over-driven incand .

BUT it is in a vacuum as opposed to say halogen (like krypton and xenon) gas which retard the vaporization point to achieve about 3000-3200K max color temp (max color temp at vaporization of filament = 3400K in halogen gas).

A vacuum bulb achieves lower color temps even if over-driven - it's simple physics any higher color temp the tungsten filament would vaporize.

My guess is that a vacuum bulb cannot exceed about 3000K(?) so produces about 2800(?) - so the Preon 2 WW would appear cooler (w more blue) as its nominal rated color temp is supposed to be about 3100K - but the incand bulb may show more red than the WW LED -

The more relevant comparisons would be the side-by-side beamshots of the the WW vs 2AA MiniMag and 1AAA Solitaire (Post #21) both of which are Krypton lights at about 3000K(?) - in the pics the krypton incands do show more red in comparison....

 

[UnknownVT]

I'm really excited to see that LEDs are starting to perform like incans, although seeing a little green in the 9P beam kinda puzzles me.

Yes, that kind of got me too - but we are talking about side-by-side comparisons - where the eye can be very critical in picking out differences.

I think the SureFire 9P is an over-driven tungsten/xenon gas bulb - this probably achieves in the region of about 3200K color temp - which is very slightly higher than the WW emitter (~3100K) - plus driven by a single AA the WW LED may not quite achieve the rated CCT. There is a very slight tint of pink'ishness in the WW emitter - so in contrast/comparison the SF 9P will look a bit cooler more blue'ish - but perhaps that translates into more green'ishness(?)

See Post #21 where I compared the WW LED with Krypton incands - 2AA MiniMag and 1AAA Solitaire which would have lower color temps of about 2900-3000K(?) and had more red,
and in comparison the WW emitter was a bit more green'ish!

 

[LEDAdd1ct]

1) A confession:

I always thought your handle meant you lived in Vermont. I apologize.

2) An expression of gratitude:

Vincent, thank you for all your hard work in this thread. You really have gone to tremendous lengths to depict the differences between tints, and the time you have spent explaining in words the minutiae between what the camera "sees" and what we see is a testiment to both wanting to help others, and, quite possibility, the drive to document, discuss, and dissect which grips all of us in this (occasionally insane) hobby.

I tip my LED-adorned hat to you.

 

[UnknownVT]

I always thought your handle meant you lived in Vermont. I apologize.

no apologies necessary - it was kind a deliberate choice on my part -
that's why I remain "Unknown" -
as for that part of the handle see this link

thank you for all your hard work in this thread. You really have gone to tremendous lengths to depict the differences between tints, and the time you have spent explaining in words the minutiae between what the camera "sees" and what we see is a testiment to both wanting to help others, and, quite possibility, the drive to document, discuss, and dissect which grips all of us in this (occasionally insane) hobby.

Thank you so much for the kind words.

Like the rest here I am a flashaholic - and I try to convey what I see and what I normally do when I get a new flashlight - mostly I compare it with flashlights I have that I think are close. I do not use any specialized measuring instruments - and use what most people would have at hand (eg: digital camera) - so most of what I do should be fully reproducible.

But the beauty of reviews on this forum is that I get feedback and comments which often leads me to investigate more in areas that I may not have considered when first doing the review - this one is a good case in point - where even though I knew initially that WW emitters would/should be compared with incandescent - I didn't realize that would be the main interest - which led me to compare more with other incandescent lights - which I was doing anyway - but now there was real interest. Similarly with outdoor leaves shots - I knew there would be interest - but the feedback confirmed it.

The area I was not aware of was the flesh tones - and you can see I struggled with that one - because it is hard to represent what we see with photos. Fortunately again from feedback and responses it seems that what I observed, and retrospectively "saw" in the photos - that neutral seemed most pleasing - but the WW enhances about as well as incandescent - was about right.

So it is the feedback and responses that make the reviews better.

Thanks for the compliments.

 

[bodhran]

The other day I was attempting to start an I.V. in a dark room and asked the family if they could turn on more lights. I had forgotten that I had put my ww cr2 mini in my pocket earlier until one of the Firemen mentioned, Hey Doc, you always have a flashlight on you. I turned it to medium and had one the the guys hold it for me. My first good look at flesh tones with the warm white, and it was great. No problem finding a vein and the Firemen were impressed also. After having enjoyed a nice Memorial Day weekend, I've noticed the reds on my sunburnt body are pretty impressive also under the ww.

 

[UnknownVT]

My first good look at flesh tones with the warm white, and it was great. No problem finding a vein and the Firemen were impressed also. After having enjoyed a nice Memorial Day weekend, I've noticed the reds on my sunburnt body are pretty impressive also under the ww.

Great input - thank you so much -
it is really valuable to get input from people who have real serious use for the Warm Whites.

Thank you.

 

[ky70]

...The reason the 3.7V Li-Ion 14500 isn't any brighter is because of the current regulating circuit.

4Sevens Quark series have Buck-Boost regulating circuits which bucks the voltages above Vf (forward voltage) down to the spec'd safe levels - and for voltages below Vf as in 2x AA (~3V) it Boosts the voltage to the Vf. So at the LED emitter - a 3.7V Li-Ion 14500 which is likely to be above gets Bucked to the Vf and the 2x AA NiMH (~2.4V nominal) which is below gets boosted to Vf -
therefore the output is the same as in both cases only Vf is presented.

Vincent, thanks for this explanation, but I have a question about if their is buck-boost regulating circuits in the qmini 123 (regular). The output for the qmini 123 is noticableably brighter with a rcr123 (3.7v) compared to cr123 (3.0v). Does this mean the qmini 123 does not have buck-boost circuitry?

 

[UnknownVT]

Vincent, thanks for this explanation, but I have a question about if their is buck-boost regulating circuits in the qmini 123 (regular). The output for the qmini 123 is noticableably brighter with a rcr123 (3.7v) compared to cr123 (3.0v). Does this mean the qmini 123 does not have buck-boost circuitry?

From your description it sounds like a regular boost circuit -

The Q-MiNi 123 specs actually says:
" Battery: One CR123A (3V max) "

A regular boost (only) circuit is by-passed when the battery is above Vf -
so in effect the LED is on direct drive - thus gaining in extra brightness.

Note: the operative word above Vf - so by definition the LED is over-driven with a voltage that is above Vf.

The lower levels, I believe, are still there because the MiNi and Preon series use high frequency PWM.

Even though there is plenty of anecdotal evidence the light obviously "works" on 3.7V Li-Ion Rechargeable, and there are plenty of people who are quite happy using that on other flashlights which only have boost circuits (always nice apparently "getting something for nothing") -

I still strongly suggest not using it - as it is out of spec,
or if you are willing to risk it doing it very sparingly
(remember do this at your own risk - and this flashlight would not be under warranty for this out of spec usage)
- as I have a Fenix L1D-Q5 that I used to use as one of my comparison flashlights with very occasional Li-Ion -
that has turned a distinct violet blue in tint -
so much so that I had to replace it for comparisons.

So perhaps Li-Ion may not cause sudden death -
but probably long term permanent injury?

 

[ky70]

Thank you Vincent for that detailed explanation :twothumbs

Though I did like the exrta brightness of the mini using a 3.7v, I switched a while ago to a 3.0v LifeP04 123 battery so I still get the benefit of guilt free lumens without the risks of frying the LED.

 

[Rat6P]

Just had to resurrect this.
Epic.
Thank you to the OP.