LED Retrofit of my Laborlux 12

[einman]

Ok. A while back I had purchased a retrofit kit from E-bay for my laborlux. The rheostat had been acting up and was not reliable. I could rebuild the switch or take this opportunity to retrofit it to LED. Gone would be the issue of replacing bulbs not to mention the intense heat over time. So here are pictures of the retrofit. It took about 5 minutes and performs great. More light is available, no "daylight" filter required.

[75RR]

Hi einman,
Do you get any banding on video?
Do you know the make and type of LED in the kit?

[einman]

Hi einman,
Do you get any banding on video?
Do you know the make and type of LED in the kit?

I cant say. I just installed it and looked at a few slides. I have not made any videos yet. Let me charge the battery in my camera and I will make a quick video and post it.

[einman]

ok. I did a very quick video. First I noticed it is very blue. Some white balancing is in order. But I do not see any significant banding.

http://vid596.photobucket.com/albums/tt ... I_1156.mp4

[75RR]

Thanks for taking the time to do this einman. Much appreciated.

I see some faint thin banding - it is more readily apparent in the clear areas.

Do you remember the sellers ID?

[einman]

Thanks for taking the time to do this einman. Much appreciated.

I see some faint thin banding - it is more readily apparent in the clear areas.

Do you remember the sellers ID?

I thought i noticed some very faint intermittent banding but not significant. Why is that a problem with LED systems in general or just specific ones?
Sure his name was daedal2005

[75RR]

Why is that a problem with LED systems in general or just specific ones?

LED systems in general.
It is to do with the pulse rate when dimming.
See link:
http://www.photomacrography.net/forum/v ... hp?t=25718

Crater Eddie has field tested his conversion and it avoids this problem.
See link:
viewtopic.php?f=12&t=194

Thanks for the seller ID

[einman]

Why is that a problem with LED systems in general or just specific ones?

LED systems in general.
It is to do with the pulse rate when dimming.
See link:
http://www.photomacrography.net/forum/v ... hp?t=25718

Crater Eddie has field tested his conversion and it avoids this problem.
See link:
viewtopic.php?f=12&t=194

Thanks for the seller ID

I am not savvy when it comes to electrical devices. But after quickly reading over the information am I understanding it correctly but altering the frame rate of the video could minimize or eliminate the banding. Given the video I posted had very little perhaps I could alter the frame rate slightly. The camera is capable of quite a bit. I would be interested in anything the seller shared in terms of construction.

On the flip side I can change back over to he original lamp assembly in about 5 minutes.

[75RR]

... altering the frame rate of the video could minimize or eliminate the banding.

I think one idea is to increase the frequency of the pulses to at least twice the video frame rate.
Though it would still be visible to the naked eye when viewing the sample through the eyepiece.

Alternatively, one can eliminate the pulses using the method Eddie used.

I would be interested in anything the seller shared in terms of construction.

I am having something made up, wanted the sellers ID in case it does not work.

[gekko]

I don't think banding has anything to do with LEDs as such. I use a tungsten filament and I get banding on occasion. Rather it has to do with the flicker in the light (whether LED, tungsten, or fluorescent). Tungsten is usually run on AC (unless DC is necessary for other reasons). LED is run on DC obtained by (normally full-wave) rectification. So, basically in all cases the flicker will potentially be at twice the mains frequency. In the case LED, if the power supply is adequately filtered or regulated, it should not flicker. The bands appear where there is flicker at (or close to) a multiple of the camera's frame rate. So, in the US, where the mains frequency is 60 Hz (flicker rate 120 Hz), if the camera's frame rate is (or very close to) 30, 60, etc. Hz, then bands are liable to appear. The best way to avoid them is to use well-regulated DC. At least that is my understanding.

[einman]

The LED system I purchased uses an AC/DC adapter operating at 50/60HZ and 1.6A. Much like used with laptops. Currently the little amount of banding is not an issue with me. It could be when I start to make more videos. So would turning up the dimmer and thus the strength change the pulses and possible eliminate the banding?

I am talking frame rate and etc because I already have the system so have no desire to build one.( i probably could not anyway..too many irons in the fire as it is)

[Crater Eddie]

I have watched this vid several times and I do not see any banding. ???

Edit: Ok, I saw it this time. Is is very slight.

[gekko]

Sorry, einman: I didn't intend to imply that your video showed bars, as I actually didn't see any, so I assume that what bars are there are just too subtle to matter practically. Both 75RR and CE appear to say basically the same thing-- hardly visible to them, invisible to me...

[75RR]

I don't think banding has anything to do with LEDs as such.

I stand corrected. It is how the dimming is achieved that can cause banding.

In your case it is very slight banding.
You can probably confirm this with Eddie - but you might only need to add the module to your setup.

[gekko]

I think the reason why "my" banding is not too obtrusive is that the filament, unlike the LED, has thermal inertia, and when the sine wave current reverses passing through zero, the filament would still be hot and would still emit light, but the light is somewhat modulated at 120 Hz (I guess somewhat like an LED supplied by an incompletely filtered rectified DC source). I think you forget that I'm not using LED, so the module you suggested won't help unless I convert-- but thank you for your optimistic assumption that I will be converting to LED!

[75RR]

Was referring to einman's banding and the possibility that the module might be added to his retrofit kit.

Should have been clearer!

[The QCC]

I have retrofitted a 10W LED on my B&L microscope. It is the third 10W LED unit. The first two were defective with severe banding and shut down issues at high intensity and were returned under warranty.
All three LED units use a 2000 Lumens Cree XM-L T6 unit.
The third and last one I will buy does not shut down at high intensity, but still bands slightly around 50% intensity.
The LED light uses a 12VDC 2A switching power supply. I cannot attest to the quality of the power supply.
As a research test, I will connect a 12V battery and see if it the banding is still present. This will determine if the banding is from the power source or inherent in the LED chip design.
I use Canon cameras with Live View and the banding is evident in the screen previews and in still image captures.

I purchased this unit on eBay

The diffuser on the LED unit is a bit lame, so I added my own diffuser above it using old filter rings,

IMG_0149.jpg (79.99 KiB) Viewed 12667 times

einman:
I apologize for adding an image to your thread.

[einman]

Feel free to post all the images you want. I recognize the design as being similar to ones for sale on E-Bay.

[billbillt]

I think you did a super job in converting....

[apochronaut]

very classy , professional looking job. i have a couple of questions . i have been fooling around with leds for a while and my chief gripe with them is the excessive blue colour value, so i have played with yellow filtering. with filament bulbs, the opposite is true, so some degree of blue filtration is almost always the rule. are you finding the excessive blue colour a problem? our eyes adjust and tend to normalize skewed colours but photo or video doesn't.
do you have a problem with that tile floor in your lab? they can be brutal if you happen to drop a lens or something.

[The QCC]

I used both high power LED (20W) and 100w halogen lighting and do not use filters on either light source.
My camera capture programme does all the colour balancing.

I may be the exception, but I do not use the eyepieces on the microscopes. All viewing is done on the calibrated display through the Canon cameras.

[apochronaut]

Yes; I can see that possibility. This brings up a whole other question , though, that has been stammering from time to time in the back of my mind. I didn't want to hi-jack Einman's thread with it, so can I start another thread with your answer?

[The QCC]

A very good idea.
This thread is deviating from the original topic.

[billbillt]

For me, the "warm white" LED's seem to lack the intense blue tinge...

[einman]

very classy , professional looking job. i have a couple of questions . i have been fooling around with leds for a while and my chief gripe with them is the excessive blue colour value, so i have played with yellow filtering. with filament bulbs, the opposite is true, so some degree of blue filtration is almost always the rule. are you finding the excessive blue colour a problem? our eyes adjust and tend to normalize skewed colours but photo or video doesn't.
do you have a problem with that tile floor in your lab? they can be brutal if you happen to drop a lens or something.

Yes now that you mention I do. Attracts objectives like a magnet!!!

[clipi]

Hello..

Could you please tell me where did you get the retrofit kit for laborlux?
Manufacturer? Led type?
Thanks so much!!

[billbillt]

Hello..

Could you please tell me where did you get the retrofit kit for laborlux?
Manufacturer? Led type?
Thanks so much!!

Hi,

This example was home made... It is a relative simple project.. I have seem some on Ebay that someone has made for sale at elevated prices... It actually costs very little to make...

BillT

[einman]

very classy , professional looking job. i have a couple of questions . i have been fooling around with leds for a while and my chief gripe with them is the excessive blue colour value, so i have played with yellow filtering. with filament bulbs, the opposite is true, so some degree of blue filtration is almost always the rule. are you finding the excessive blue colour a problem? our eyes adjust and tend to normalize skewed colours but photo or video doesn't.
do you have a problem with that tile floor in your lab? they can be brutal if you happen to drop a lens or something.

Ha..just reading some old posts and caught this one. The answer is yes I have lost a few objectives initially to this tile floor. So now I am verrrry careful!

[einman]

Hello..

Could you please tell me where did you get the retrofit kit for laborlux?
Manufacturer? Led type?
Thanks so much!!

E-bay. There is a company that specializes in LED retrofit kits. Just search led retrofit in microscope accessories and parts.

[clipi]

Thanks for your reply.

I think you are refering to RetroDiode but I guess they don´t make that model anymore since I could not find it in their website.
It look very nice.