fluorescence metoo

[iconoclastica]

For some years I have awed at the beautiful and colourful images posted here, taken with the fluorescence microscope. And by each one I firmly confirmed my personal resolution that I wouldn't be doing that, I draw the line before the high pressure mercury lamps step into my house. Oh well, that was those times before I saw this complete set, apparently in good maintenance, on our local second hand market place. It couldn't harm to make a low bid, I thought. Which was accepted within the hour, no additional shipping cost, here it is.

I believe there are people who say that the best starting point for entering a new technology is no prior knowledge. For the moment I cling to that opinion

Anyway, I 'll have to find out everything now. More questions will follow, I presume...

The first one is about the type of lamp. In the manual for more or less but not exactly this power supply (Nikon, by the way) it says it should be used with USH-102DH mercure lamps. The lamp that came with the unit sits in a USH-103D-box, which is not original, for the lamp itselfs is an Osram HBO103W/2.

Is this of any importance, and if not so, what types of lamps could I use when this lamp will be finished?

[René]

A LED lamp, but check what excitation wavelength you want to use.

Groetjes, René

[iconoclastica]

A LED lamp, but check what excitation wavelength you want to use.

would be interesting to see the effect of the 1600V starting current on the LED. I don't think it will emit at a specific wave length, but for sure it will be SHORT.

[jmc]

First thing, check the spec sheets of the different bulbs. They could be different manufacturers versions with the same specs, which SHOULD be ok to use interchangeably, but I'll admit it is not something I'd want to do without knowing more about the bulbs. If not, then best to just use the original recommended ones.

Do you have filters? You'll need to filter the light from the bulb for fluorescence work. The filters you need will depend on the wavelengths you want to use to initiate the fluorescence, and are there to remove anything that you don't want hitting the subject. You'll also need filters for the camera, to filter out the wavelengths you don't want to reach the camera.

UV safety - do you have some good UV blocking safety glasses? If not then you'll need some before you switch it on. These light sources are incredibly intense UV sources, and that can burn or blind you if you're not careful.

I'm certainly no expert on UV fluorescence microscopy, but have dabbled, and have been working with UV photography for a number of years. I cannot emphasize enough the need to respect these types of light sources, so however you proceed be safe.

[pbraub]

I cannot agree more with jmc and others. you should be careful with what you do (and follow the instructions in the manual closely). There are some specifics like "not touching the glass" and not looking into the unshielded lightsource that come with using a arc source.

Osram ans Ushio both make bulbs that fit, for olympus at least i know that they recommend the usihio (102D in my case) but there is a compatible osram bulb out there. From what our service tech told me nearly everyone switched back from osram to ushio because the bulbs last longer and have a more stable output. this is in line with my experience. the osram bulbs are done at 250h, with the ushio (rated for 300h) you can often squeeze out 400.

Also be aware that mercury short arc lamps can be very inconvenient to use - they need time to warm up and stabilize - usually 30-60 min (if you want to do stacks unstable light sources are a pain in the butt), if you turn them off you cannot turn them on immediately afterwards but have to wait until the bulb has cooled (also an hour or so), they last as mentioned above for 250-300 h, maybe a bit longer. If you exceed their lifetime they either do not start at all, flicker, or explode. The flickering will make stacks lit unevenly, and the exploding issue is not theoretical, i had this happening twice (within 15 years or so), both times my employer thought (against better advice) that he could save money by not buying new bulbs!

[iconoclastica]

First thing, check the spec sheets of the different bulbs. They could be different manufacturers versions with the same specs, which SHOULD be ok to use interchangeably, but I'll admit it is not something I'd want to do without knowing more about the bulbs. If not, then best to just use the original recommended ones.

These oldies come without a manual, so what are the spex? The front panel reads: "HBO 100W/2". The first two parts I understand, but what does the /2-part mean?

from te osram-website:
HBO 100W / 2 100W 20V
HBO 103W / 2 103W 22V

So my 103 is driven somewhat below its specs? On the positive side, it is brighter and has a longer life span (300h); that could be the 3 in 103 instead of 102 in the type numbers. In this context: I was surprised to receive the power supply set to 220V rather than to 240. We made that change some 30 years ago. Could it be that the previous owner set that deliberately knowing there's a 22V lamp attached? The obvious thing would be to measure the output voltage, but either the PS detects there's no lamp started, or my probes are too short to make contact.

On the bright side: it was up and running within an hour:

[jmc]

For the specs of the lights;

USH-102DH - https://estore.ushio.com/products/5000274-ush-102dh
USH-103D - https://estore.ushio.com/products/5000273-ush-102d
Osram HBO103W/2 - https://www.osram.com/ecat/HBO-HBO-Disc ... ZMP_56327/

They all come with spec sheets. The Osram 100 and 103 look pretty much identical other than lifespan and output (https://www.osram.com/ecat/HBO-HBO-Disc ... 1_1028555/), so perhaps the 103 is the newest version? If in doubt, a call to your regional Ushio and Osram reps would be advisable.

[micro_pix]

I have both of these bulbs for my Olympus and my research agrees with the above - the 103D is newer and is rated at twice the life.

The Olympus documentation recommends a 5 - 10 minute warm up before use and a 15 minute cool down after switching off before switching on again, this timing has worked fine for me when stacking.

I do try and set up everything with transmitted light then switch it off before opening the slider to illuminate with UV as with many subjects the bleaching effect is pronounced and the fluorescence weakens as you go through the stack, some subjects maintain an even fluorescence over the same period. For extra safety I don’t use the eyepieces when doing fluorescence, I use my iPad linked to the camera - and I still wear goggles!

Dave

[iconoclastica]

Thanks Dave, that's interesting hands-on experience. I had discovered the transmitted light option for searching and initial focusing for the reasons you mention. The orange protection shield seems to work quite well, as I can see no light with one and little light with the other filter cube. But there's a problem to center and focus the light. I can do that only when looking at the projected image on the stage directly, at the penalty of seeing bright blue stars the next day or two. Obviously, that is not a safe way to do that. Do UV-blocking non-darkening goggles exist?

[micro_pix]

I use a centering device that screws in to the nosepiece, like this, https://www.ebay.co.uk/itm/Nikon-Epi-Fl ... 3039981049 it’s probably worth investing in one but if it is roughly correct I can often centre and focus by looking at the fluorescing image on the ipad. Not sure that it would be the same on the Nikon but the narrow light coverage of the epi fluorescent illumination makes the centring easy and the fluorescence is brightest when in focus.

Dave