Volpi fibre optic light

Have questions about the equipment used for macro- or micro- photography? Post those questions in this forum.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

lauriek
Posts: 2402
Joined: Sun Nov 25, 2007 6:57 am
Location: South East UK
Contact:

Volpi fibre optic light

Post by lauriek »

Can anyone here with a Volpi fibre optic light unit tell me whether the PSU is external, or easily changeable?

I mean if I buy a US unit with a 110V PSU would it be easy enough to change it to a UK 240V PSU with the correct voltage output and enough power capacity?

I've got quite a few power supplies lying around and if I don't have one with the correct output I expect I could source one okay..

g4lab
Posts: 1437
Joined: Fri May 23, 2008 11:07 am

Post by g4lab »

Most fiber optic light sources these days use either a 15 volt 150 watt (10 amp) EFR bulb or a DDL, EKE EJA EJN bulb of 20 or 21 volts and 150 watts.
There are differences in the life, color temp and focal point. If memory serves Volpi uses the EFR bulbs.

Most Volpi fiber optic sources sold in the US were made in their Auburn New York facility. I have a couple of them and I will look and see whether the supplies are switchable. I think they are not. Any step down unit that runs cool with about 200 watts hanging on it should do fine.

Charles Krebs
Posts: 5865
Joined: Tue Aug 01, 2006 8:02 pm
Location: Issaquah, WA USA
Contact:

Post by Charles Krebs »

Laurie,

I've got a couple Volpi NCL 150's. 120V/60Hz/170watt internal power supply. Uses 20V/150watt DDL or EKE. Have no idea about how easy "swapping" power supplies can be.

Graham Stabler
Posts: 209
Joined: Thu Dec 20, 2007 11:22 am
Location: Swindon, UK

Post by Graham Stabler »

If the PSU is linear rather than switch mode you could probably just switch the transformer. Otherwise you could just run the bulb straight from a suitable power supply based on its voltage and current requirements.

You can also get transformers that convert 240v to 110 but this may be a bulky solution. And you must get one that matches the required power.

http://www.maplin.co.uk/Module.aspx?ModuleNo=13358

I'm actually dismayed by my light source, it is 150W Dolan-Jenner PL-800 and it cost a pretty penny and I feel robbed. A simple PSU, an IR filter a dimmer circuit oh and a fibre clamp that is next to useless as after 5min it is loose. They are just a bulb in a box really :)

Graham

AndrewC
Posts: 1436
Joined: Thu Feb 14, 2008 10:05 am
Location: Belgium
Contact:

Post by AndrewC »

Graham Stabler wrote: I'm actually dismayed by my light source, it is 150W Dolan-Jenner PL-800 and it cost a pretty penny and I feel robbed. A simple PSU, an IR filter a dimmer circuit oh and a fibre clamp that is next to useless as after 5min it is loose. They are just a bulb in a box really :)

Graham
Not even any condensor optics ? Robbery !

rjlittlefield
Site Admin
Posts: 23564
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

AndrewC wrote:Not even any condensor optics ? Robbery !
Well, it's not quite that bad. The replaceable "bulbs" in these things have integral lenses and mirrors that do a pretty good job of delivering light to a fiber bundle. Here's a picture of mine, running on very low power, shining on a piece of black paper. I believe the PL-800 uses the same bulb.

Image

On the other hand, that fancy bulb can be purchased for $20 retail. The power supply in my unit (unbranded, but looks just like the HEI-FOI-110 shown here) is a high frequency switcher that completely eliminates the flicker you might expect with 50-60 Hz line power. It would be nice to have an iris to adjust brightness without changing color, but mine doesn't have that. I'm confused about whether the PL-800 has an iris or not -- I've seen manuals and advertisements both with and without.

Anyway, yeah, "bulb in a box" is a pretty good description!

--Rik

rjlittlefield
Site Admin
Posts: 23564
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

Graham Stabler wrote:You can also get transformers that convert 240v to 110 but this may be a bulky solution.
I recommend against this approach. Once upon a time I fried a number of US-spec power supplies by running them on German power stepped down to 110-120V. It took a while to catch on that the supplies were overheating because they didn't like 50 Hz instead of the 60 Hz they were designed for. They'd work OK for a while, though warm, but the MTBF dropped to about a week.

--Rik

g4lab
Posts: 1437
Joined: Fri May 23, 2008 11:07 am

Post by g4lab »

Dolan Jenner is a venerable old company and probably the first to make reasonably priced fiber optic illuminators. The models 170 and 180 still made I think are little more than a transformer,fan, and lamp holder. Although the fiber connector is a little crude it is so easy to adapt that even the company's adapters for other makers fibers are very inexpensive.

The NCL 150 that Charles mentions is essentially a somewhat nicer copy of the above. Was sold under both the Scholly and Volpi names. It does have a less versatile but much nicer fiber grabber and some have irises and some don't.

Having been a student of this subject for a while, my opinion is, that the one to buy, if you are not already committed to a particular unit, is a FOSTEC or Schott/FOSTEC. A model with an iris. The lamp holders in these have movable focusing distance (two screws) to accommodate different bulbs.
They have an IR filter which is nice for the fiber ends which can get scorched. The iris leaves are made of stainless steel. They have accessories like shutters and remote and computer control if you need them. And lastly, but certainly not least, it appears that they sold more to industry, than other brands, so different types of fiber and accessories, appear on ebay more than others. And they do have a wide variety of different fibers and accessories.

I do like Volpi stuff too. But there is not nearly as much of it out there.

FOSTEC was acquired by Schott who have recently closed the US manufacturing facility in Auburn New York. I believe the equipment was sent to the Far East but I don't know where.

Swithching power supply equipped units do have the advantage of operating internationally. Some have a switch to operate while others autosense the power source and work accordingly. I don't care for them because when they die they are difficult or impossible to fix. I had an ophthamologist in Panama send me a Zeiss switcher from his slit lamp.
It had been struck by lightning. It was hopeless. A transformer supply would have blocked the lightning stroke by its large inductive reactance.

I don't think the switching frequency should make much difference because I think the thermal mass of these QH bulbs doesn't pass along much AC flicker. (Fluorescents of course do which is why they need to be high frequency) If the unit has an SCR/Triac dimmer you may hear filament noise. If there is flicker it is more likely a malfunction of the dimmer causing hunting.

The FOSTEC/Schott line is not interchangeable with the Schott line which is nice but very expensive. The fiber couplers are different. Schott uses a very sturdy collet grip. But doesn't allow for using other fibers very well.

There are some medical illuminators that have a Jacobs chuck type arrangement that can bite any fiber less than about 13mm in diameter. That is a nice innovation. (there are many different non standardized types of fiber optics in the OR)
Being made for the OR they are built like tanks. They are clunky and ugly but they work great. I have an extra one if someone is interested. US power only. They also have lamps on a turret so surgery is not interrupted to change bubbs.

If you are not in a hurry you can still equip yourself with Fiber Optics and illuminators on ebay for a small fraction of buying a new one.

Graham Stabler
Posts: 209
Joined: Thu Dec 20, 2007 11:22 am
Location: Swindon, UK

Post by Graham Stabler »

Rik,

The PL800 does indeed have an iris and yes it does use an EKE21V150 bulb. I just bought a stack of spares, not from Edmund of course, they seem to have a X2 pricing policy.

Another thing I noticed that these bulbs look almost identical to the sorts of things you buy for your kitchen only with the front glass removed. I've removed the front glass from spots before to make a tiny vac former so it makes me wonder if there is a host of lighting solutions one could make very cheaply if one wanted. Perhaps there are issues of colour and they aren't generally 150W+ from my recollection.

Cheers,

Graham

g4lab
Posts: 1437
Joined: Fri May 23, 2008 11:07 am

Post by g4lab »

Consumer and even display light bulbs usually operate at much lower color temperatures in order to give acceptable life. They also have very different focal characteristics than the lamps that are used for FO illuminators. The size and distance of the focal spot would not get much light into your fiber. If you do a picture like Rik's the spot will be comparatively huge.

You are correct also that they don't come in 150watt because the surface temp of the bulb is too much for bare operation. Needs to be in a luminaire when over about 75 watts or so.

The difference between DDL and EKE is color temp and hours.
Some of these bulbs were originally intended for eight mm projection and were a natural fit for fiber optics when that went away.

rjlittlefield
Site Admin
Posts: 23564
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

I don't think the switching frequency should make much difference because I think the thermal mass of these QH bulbs doesn't pass along much AC flicker. (Fluorescents of course do which is why they need to be high frequency) If the unit has an SCR/Triac dimmer you may hear filament noise. If there is flicker it is more likely a malfunction of the dimmer causing hunting.
I should clarify. When I say "flicker" I don't mean variations that are normally visible by eye, but rather show up as small exposure variations when you photograph with high shutter speeds. It's not a big problem in most cases, though I did once run into a strange halogen bulb that had a diode built into its base. As a result, it was actually running on unfiltered half-wave-rectified DC, putting out big pulses at 60 Hz instead of little ripples at 120 Hz. That one got replaced in a hurry.

When I first got my fiber illuminator, I was curious about its output ripple. So I shined it on a photocell ripple detector...and saw nothing. Great, I thought, this must be a DC supply. But when I metered it, I discovered no DC at all -- just 12-22KHz AC, depending on power setting. Quite unexpected.

This one is fixed input, by the way. 120 V 60 Hz, not switchable, not auto-sensing.

--Rik

g4lab
Posts: 1437
Joined: Fri May 23, 2008 11:07 am

Post by g4lab »

Scanning cameras also like DC lamps and can show banding if the resolution and exposure result in movements that are related in frequency to the ripple. But again more of a problem with fluorescent illuminators. These cameras are not common but there are a few out there.

The FOSTEC/SCHOTT DCR II and III feed the bubb with DC but have auto sensing, love all the world, power supplies.

The voltage adjusters on the transformer coupled lightsources are sometimes on the line side and sometimes on the lamp side. Even though the transformer is a big ugly inductive load if they derate the triac enough it will work satisfactorily. On the old Dolan Jenners they just had a big ceramic power rheostat to absorb the power that was not sent to the lamp.

Putting the triac on the line side keeps the fast rising spikes out of the lamp filament which doesn't like them and sometimes will respond to them by jumping apart if already getting elderly. The transformer smooths those sharp rises and makes them more palatable for the bubb.

lauriek
Posts: 2402
Joined: Sun Nov 25, 2007 6:57 am
Location: South East UK
Contact:

Post by lauriek »

Wow thanks for all the info all! (And Thanks Betty for bringing that other thread to the fore) - plenty of searching on Ebay to do now!!

Post Reply Previous topicNext topic