Continuous light for macro

[boomblurt]

GDay from Australia.

Been a long-time lurker and love the site. Please excuse me if this has been discussed before but I can find little here, or elsewhere, regarding the use of continuous light for macro photography. I have searched, really

In particular I am curious about the pros and cons of fibre optic illuminators as used in microscopy; eg a 150W Halogen cold-light source (or even LED).

The lenses used will be Canon 100/f2.8L, MPE-65 and a Nikon 10x/0.25 infinty objective on a telephoto lens.

Thanks very much for the site and for any information.

[Craig Gerard]

Some pros and cons regarding FO halogen illuminators.....it can depend somewhat on the brand. Generally they provide a rather powerful, adjustable intensity light source and require light guides. They can run a bit noisy and can introduce vibration concerns if positioned on the same surface as your camera setup; but overall they are very effective and widely used. Schott/Fostec and Volpi are two good brands. The units originating from the Orient are best left over there. If you decide to go down this path and have trouble sourcing a unit locally let me know.

LED technology has progressed in recent years and many members use such devices for macro. There are a number of alternatives.

The Ikea JANSJÖ LED work lamps are one alternative, but they are not very bright, so long exposures are necessary. There are also some batch related inconsistencies in the output which could become an issue if you are using more than one unit as there may be differences in the colour temperature of individual units. These lights can be purchased in Australia from an Ikea store or via Ikea Online.

The Metz Mecalight LED-480 (72 High CRI LEDs) appear to be good units. I currently have three of them running on AC power. Output is adjustable and they provide good (sufficiently bright) illumination. I like them, but have not performed any serious analysis to date. A quick Google search will list retail outlets in Australia stocking such items.

There are some LED fibre optic illuminators available which are compatible with a range of light guides, but such units tend to be rather expensive and the less expensive ones are probably best avoided. I picked up a Schott LLS for a good price on eBay and I'm thus far happy with its performance.


Craig

[g4lab]

I have various medical arc lamps and fiber optics available. Surgical headlights.

They have better color rendition than LEDs (xenon arcs are the best continuous artificial daylight source there is 5 to 6K degrees Kelvin.

They have adjustable intensity before the fiber (by diaphragms or perforated plates) and very high color rendition indices which they have not yet quite managed with LEDs.

I have more than I will ever use and will be happy to sell them quite reasonably (ie. ebay prices) Send me a PM if interested.

Quartz halogen fiber optic illuminators are widely available on ebay and can frequently be gotten for prices that border on theft. I like FOSTEC Volpi and Dolan Jenner in that order due to quantity of light guides available. Schott are nice but expensive and the guides even more so.

Quartz halogen are limited to about 3400 degrees Kelvin color temp.
When selecting a unit pick , generally a 150 watt unit that uses either a 20-21 volt lamp (EKE EJA DDL ) or a 15 volt 150 watt (schott and some volpi) Maybe the 250 lamp (ELH I think)

Avoid the 80 watt units and lower power. The ones from China still do not seem to have all their QC problems beaten into submission.

[Cyclops]

I have used LED lights before I got a flashgun to good effect. White balance can be a little cool, giving a slight blue tinge with some lights.

I've also used the flashlight on my phone which is really bright!

[Chris S.]

Boomblurt, welcome to the forum!

I'm currently using three Schott/Fostec Ace1 illuminators--good, workhorse units purchased second-hand. They use EKE halogen bulbs. They are on a hanging shelf, supported by ropes suspended from the ceiling, to avoid transmitting vibration to the macro rig (this is, as Craig noted, very important). While I also have flash equipment, I find myself using continuous light more and more. It is far more WYSIWYG than flash, and I find it more consistent and less problematic. Notably, this is the opposite of what I would have predicted two or three years ago.

If you go shopping, I'd recommend limiting your search to illuminators that have an iris. The ability to modulate the light without changing the color temperature is important. Using the dimmer on the unit has a dramatic effect on color temperature; on my units, if I set the dimmer dial to anything less than 80 out of 100, the light becomes too "warm" to correct in-camera.

I happen to like illuminators that have a shutter as well as iris, but doubt this would be important to most photographers. Units equipped with both shutter and iris are not so easy to find.

When you shop for light guides, I suggest you avoid the semi-rigid "gooseneck" types, which can be annoying. The flexible light guides that need to be clamped in position are much easier to work with.

I like FOSTEC Volpi and Dolan Jenner in that order due to quantity of light guides available. Schott are nice but expensive and the guides even more so.

Gene, would you be able to explain Schott/Fostec branding a bit? You likely know their history, and I do not. Presumably, these were once separate companies that have merged some time ago? Of the three Ace1 units described above, two are labeled "Fostec," and the other "Schott." Otherwise (and but for the fact that only two have shutters), they seem to be the same model. Certainly, they accept the same light guides.

A Dolan-Jenner unit that I have lives up to its name, as in "dolorous." My specimen is of rather poor build quality, and I would not recommend it.

--Chris

[boomblurt]

Thanks very much for the replies. I was sceptical about these lights as so little is online about their application to macro yet they seem to have some very real advantages, especially as Chris S. mentions.

Now I just have to find a suitable, cheap-ish one to buy

[scottburgess]

Craig, I too have been interested in LED video lights like the Metz (which may be discontinued, can't find it on B&H or Amazon).* But I have to wonder if there are noticeable oddball effects from the individual bulbs in things like eye catchlights. Have you compared the bare bulbs to running them through a diffuser?

Scott

*Not to worry, B&H has similar products from Genaray, Sunpak, etc... and some of them have color temperature controls, diffuser attachments, and so forth.

[Craig Gerard]

Scott,

Good point. I'll have a look.

The Metz Mecalight LED-480 units do come supplied with diffuser panels which attach via magnets. The standard diffuser does not hide the individual LED bulbs but I always have a secondary diffuser between the Metz and the subject.

One of the main reasons I went with the Metz Mecalight was the AC adapter option. The other reason was the CRI. I've used similar units but the Metz are much better.


Craig

[g4lab]

Schott is a venerable and huge German glass company. Fiber optics and their illuminators are a tiny tiny tiny little bit of their business. They have made optical glass for Zeiss and other big German companies.

They have been in the fiber optic business and a few years ago bought the
FOSTEC company and proceeded to dismantle the factory in Auburn New York (where the Swiss producer Volpi also has a plant) They shipped the machinery to China but they still sell FOSTEC illuminators only now they say Schott/FOSTEC. FOSTEC was an acronym for Fiber Optic Specialties Technology.
The two product lines are both owned and sold by Schott but are still as separate as they were when they were separate firms. Separate in the sense that there are no interchangeable parts. Different light guides and lamps. Both in the same catalog sheets and web pages though. and dealers. The Schott branded product is more expensive both used and new.

Schott fiber optic illuminators have a very heavily over engineered collet to bite the guides. Very precise and solid and expensive. But they haven't sold as many as FOSTEC so they are only available on ebay to the extent of a small fraction of FOSTEC. Maybe 10%. They are nicely made but much harder to find various guides for. FOSTEC are very common and lots of different varieties show up all the time.

I have had three Dolan Jenners for a long time. THey were the first in the fiber optic business starting in the sixties. They are not as pretty as FOSTEC Schott or Volpi but mine work fine and give no cause for complaint. They have a nice system that allows you to use their inlluminator with anybody's fiber guide by using an system of inserts. I like that idea. That said I have done a little business with Dolan Jenner lately and they are definitely not the company they used to be. They were also sold not long ago.

All of these use the same bubbs. DDL EKE or EJA . The one with the short life in hours has about an extra 50 degrees K of Color Temp which can be helpful. The FOSTEC lamp holders allow you adjust the lamp position for the above three different flavors of lamps.

Volpi and Schott use a 15 volt 150 watt lamp. They are all extremely similar.

FOSTEC also has lamp holders with a stainless steel iris diaphragm.

I agree with the comment about "flexible goosenecks" they are officially called obedient goosenecks but I find them very dis obedient. Eventually you can get them positioned to the point that they will stay where you point them. But if you have to change setups a lot they are a big pain. A bit less so after they are broken in. Kind of like an uncomfortable pair of shoes.

[boomblurt]

Thanks g4lab. This is very informative.

Fostec has different models of illuminators for the bulb types you mentioned. Do the ones marked "DDL" on the front take EKE bulbs? Is the electronics inside the same, just the positioning varied. Also what does working distance mean in relation to EKE/DDL bulbs?

[g4lab]

The gadget that you snap the metalized reflector qh lamp into is held onto the deck that it lives on with two screws. There are either two or three sets of screw holes depending on which lamp is intended to be used. I have an installation print that shows whcih one is which. The focal length of the lamp reflectors is not identical. They come factory set for a particular lamp but the user can change them with no harm and it is easily reversible.

Similarly the lamps are either 20 or 21 volt and the power supplies (of which there are also several flavors including DC regulated. All the supplies can furnish enough voltage and current to overdrive the lamp a bit which juices up the blue and also reduces the lamp life. But one lamp is rated at a shorter life and higher color temp when operated at its rated voltage.

Of course if you don't turn it way up in routine use the life is extended. You do need to run it hot enough that the quartz halogen cycle functions properly.

[Planapo]

This is an occasion to remember Otto Schott who has to be mentioned in the same breath together with Ernst Abbe and Carl Zeiss. The cooperation of these three led to a huge progress in the devolpment of microscopes and other optical instruments.

(BTW, Schott is correctly pronounced 'shot' and not 'scot' )

--Betty

[g4lab]

Just so.
I didn't mention him because my lectures are already long and windy enough.

The glasses he developed enabled Abbe and Schott to cook up achromatic lenses and really launched the microscope business.

He also formulated "Jenaer Glasses" which were colored filter glasses.
There are people (ahem!) who collect these.

[Chris S.]

Gene, your "lecture" was just what I was hoping for. Thanks!

--Chris

[g4lab]

You are welcome Chris. I will dig up that print which I happen to know where it is because I recently referred to it. I will scan it and post it hopefully over the week end.