bogster, what flashlight- and what cutoff-patterned lamps have you used before? And was there any particular that you liked as a low beam?
I'm certainly not defending the retailer you ordered from, or the Ixon IQP as a sole lamp for all conditions, but on a dry and level road, just 16 mph max? With a 8000 candela beam? If it's not a glare-intensive road environment, low lamp aim or your vision status that contributed to your experience, it almost sounds like you should attempt to swap lamps with someone who isn't satisfied with the lower runtime and lower CCT of his Philips SR-80 Gen.2.
Derek's last and second to last photograph pretty much represent what I see from IQP lamps when pointed like his. (I might aim them a bit higher.) On a dry and level ground, how do his photos compare to what you were seeing? What these kinds of photographs do not show is the gradual greying and loss of sharpness that happens the farther one gets into the scotopic side of mesopic vision.
When I first started cycling in the dark (several years ago) I used a single LED Dinotte light which (I thought at the time) was very good. I then graduated to building my own lights and have built several configurations of single, twin and quad XP-G lights with various combinations of optics. My favourite design for road use has always been my twin XP-G light with Ledil 10 degree optics to give a reasonably tight beam with decent throw. Driving this at 1.25A I would estimate I'm getting somewhere in the region of 700 lumens.
Recently I have started experimenting with XM-L LEDs and fresnel lenses and I have to say I am very impressed. The throw is fantastic and in combination with a single XP-G light to provide fill-in closer to the front wheel almost give the " corridor of light" effect I have always been striving for.
One of the big problems though with all these type of lights (commercial or DIY) is the "shotgun" effect which is unavoidable when and LED is used as the illumination source firing forwards. The varying amount of spill depending on the power of the light can be very distracting for oncoming drivers.
Hence the main reason for buying this light was investigating the technology involved in achieving the pronounced vertical cut-off with a view to seeing if I could replicate something similar in a light of my own. The light actually uses a shaped reflector with the LED mounted at the top firing backwards at the reflector.
If you examine Derek's second last photo closely you will be able to see a number of effects.
1. Level with the first visible plant on the right is the region in my review where the light starts to get brighter. If you look at the brick pattern to the left of the plant (and closer) you should be able to make out that this region is actually darker than the area further away.
2. Closer in still, either side of the brighter centre line you can see a still darker patch.
3. Then further in still there is a dark line followed by another bright patch
This is my main problem with this light, the variability of the light pattern.
If you look at the last of Derek's photos you will see the same variable pattern replicated again although the photo has now been taken from a slightly different perspective to the first one.
The other problem is that the overall light level captured by the camera is not the same as it appears to the eye. I don't think I've ever seen a beam shot which does capture this sort of thing faithfully because a camera lens and associated image sensor is just not the same as the human eye. What the camera seems to be doing in this case is over-exposing the amount of light which is also leading to washing out the definition between the light and dark areas.
If you look at the review of the Ixon IQ and Ixon IQ Premium by Captain Overpacker on YouTube, as excellent as the review is, the pictures just do not represent what the eye sees in reality.
Don't get me wrong, I don't dislike the Ixon IQ Premium, it's a great bit of design and construction. It's just that it is severely limited in terms of its light output and illumination level and is designed for a certain market, application and use which should be taken into consideration if you expect something more of it.
If a company like Exposure could produce something with a similar design but with maybe 2 or 3 times the output in an aluminium case to handle the heat dissipation adequately, then in my opinion you might just have a winner.
p.s. I'm not the only one who thinks this. A friend riding with me last night thought the Ixon IQ Premium was a joke. He kept asking me to switch it to the High setting. He also thought the horizontal cut-off to the side was a problem but I didn't really mind this. Everyone has their own opinions obviously.