in addition to all else that has been said, its the color temps, or light output color that is difficult to get what you want....
warm white by one supplier may not actually be warm white, although it may be a shade warmer than the cool white version they sell, it will still be hard on the eyes.
and another supplier may sell one that actually has a warm white output, but the actual lumins being produced is so low that it is hard on the eyes...
as many led bulbs as I have purchased for my trucks, enclosed trailers and boats, I still have a hard time buying LED bulbs. not because of the cost, but because of the varying and/or mis-stated bulb color or intensity of the light output from it.
sometimes its hard to trust the internet to supply us with what we need, but when you find a source that KNOWS what you want, and can dependably deliver it to you, I can promise that the premium price they may charge is going to be cheaper than it will when you take a crap shoot at some bulb that fits your socket but it ends up having too much of a blue tint to it, or not strong enough for the purpose, then having to buy something to replace it..... and more than likely taking another crap shoot at another "promising" looking bulb.
but how do you know for sure?...
its really too bad there isnt some standard somewhere for LED bulbs and/or someone who does independent testing and reviews..... so the public could buy what they actually want for their purpose, with the confidence of knowing when they install it and flip the switch, it will be just right the first time.
there is such a selection of LED bulbs in different voltages and qualities, and in so many different shades and intensities between warm and cool, and so many people who dont even know the difference. understandably, it can all be a bit confusing.
I strongly believe in being frugal with a dollar and shopping around, but I also believe that "buying right the first time" is one of the very best ways to save money, but deciding on which LED bulbs I want to purchase for the interior or cockpit, without it being on a lighted display somewhere, continues to be one of the most difficult decisions to make, and have any amount of confidence that im going to be happy with what I receive.
I tried to source my own LED's (spent a year at this game) built to my own specs to sell to my customers. Price was good, product was crap and had ZERO consistency. First batch would always be spot on, place the real order and they send me JUNK. I wound up throwing away an entire $400.00 order as the color temp was not even in the realm of warm white and bordered on Spencer Gifts Glow Light purple. This is typical of the way the Chinese tend to do business. I quickly realized I would burn through lots of $$$$$$$$ before I found a REPUTABLE manufacturer.
I don't know how Jeff Field, the owner of Marine Beam, does it other than having sold a lot of the manufacturing equipment to these guys to begin with, in a previous life. I honestly don't think their is a Taiwanese, Chinese or Japanese lighting manufacturer he has not sold manufacturing equipment to. He knows them all.
When a major company like IM#RA (can't give too many more clues) gives up on sourcing their own LED product and turns to Jeff Field then you know he's doing something right.
Jeff/Marine Beam has become my #1 source for LED conversions, and for good reasons. I also love the Sensibulb but it is quite pricey.
#1 He stands behind the product (so does Sensibulb, Dr. LED not so much)
#2 The product is the color he says it is
#3 The lumen output is what he says it is
#4 He understands this industry (right down to each and every player) far better than anyone else I know.
#5 He won't sell junk
#6 His products are extremely quiet RF wise, as of yet not one single complaint.
#7 He has every possible bulb I need, plus complete fixtures
#8 I have never once had a customer complain about brightness, color or VHF/SSB/AM/FM noise when I have installed the Marine Beam bulbs. I have had them call me to ask when I would get to it, and they have been surprised to learn the conversion was already completed. "
Wow I can't tell the difference!"
#10 He is always pushing the technology and offering
innovative new products.
#11 He now has a complete line of LED navigation lights that are USCG/ABYC A-16 compliant
The Chinese are very good at "look-a-like" but they often fall flat on their face when it comes to "performs-a-like".
Who can tell me which one is the Marine Beam bulb and which one was purchased from Superbrite LED? Both are sold as warm white. Both claim the same beam width and current draw.
Identical? Not at all........
Superbrite LED (drew .2A more than the Marine Beam)
Marine Beam
Camera on fixed tripod, settings identical (manual mode) bulb test fixture 25" from door. In the real world (human eye) the Superbrite LED was a painful blue tint the Marine Beam was actually warm white. The Marine Beam also had a wider spread and drew less current.. Oh and worst of all the Superbrite LED bulb caused lots of RF noise and the Marine Beam bulb none.
....