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-   -   Thoughts on "lamping down" fresnels? (https://www.dvinfo.net/forum/photon-management/9965-thoughts-lamping-down-fresnels.html)

Matt Gettemeier May 22nd, 2003 10:33 PM

Thoughts on "lamping down" fresnels?
 
A buddy of mine on here presented a new thought to me and I hope you guys can shed some light on the subject...

How significant is "lamping down" on the quality AND CONTROL of the light from a fresnel?

Case in point. A Mole 650w fresnel uses about a 4.5" lens and handles, obviously, 650w... I would consider getting this light and just lamp it at 300w right from the start KNOWING I could go up... unless...

The Mole 300w fresnel uses a 3" lens and is 2.25lbs lighter and probably more appropriate sized for 300w... but who knows? That's why I'm here! If I go with the 300w and WANT to lamp it UP I can't...

So what's the story here fellas?

Bryan Beasleigh May 22nd, 2003 10:36 PM

It's all personal preference I guess. I actually could see a lot of difference in the quality of light between a 300 watt arri and a 650 lamped down. Same with the Strand Bambino

Josh Bass May 22nd, 2003 11:12 PM

So it's advisable to use the light with the lamp it's named after? And what about these strands? Good lights? Comparable with Arri?

Matt Gettemeier May 23rd, 2003 06:47 AM

Aaaarrrrggghh, BRYAAANNN! YOU'RE "the buddy"... I know what you think! I'm wanting to get some other input on this...

Actually I hope you're right 'cause it'll keep me from spending more... it's just that I have a problem with the fact that there's only a $30-$40 difference in 300w or 650w fresnels... and all the accessories (barndoors, snoots, scrims) are the same price so I thought going with a 650w fresnel would be a more versatile selection...?

The 300w are cute and functional, plus lighter so I won't be upset to get those either...

P.S. I'll bet you're pretty happy with those Arri's aren't you? The quality of construction on those looks "satisfying" to feel and see.

Boyd Ostroff May 23rd, 2003 07:33 AM

Well actually I have very little experience with video lighting (although ready to learn :-) however I've been doing stage lighting for nearly 40 years. There are generally two (other than wattage) things to consider in terms of lamp choice for a specific lighting instrument.

First, there's the position of the lamp filament in the bulb; as I recall this is called the LCL (lamp center line). A fresnel is designed such that the filament of the lamp must be in a specific place relative to its reflector and lens or you will get an uneven pattern of light.

The second factor is color temperature, measured in degrees Kelvin, or "K". So if you want to use a smaller lamp than the one which is "factory supplied" with a fresnel you'll need to look at a catalog, or possibly a website, and determine these two bits of data for the original 650W lamp. Then you'll have to see if there's a 300W version with the correct base, LCL and color temperature. If you can satisfy these criteria then the "quality" of the light should be the same, only less intense.

Bryan Beasleigh May 23rd, 2003 07:37 PM

Both the ushio and GE catalogue have filament location and type noted along with color temp.

The usio entertainment catalog is hard to find so make sure you book mark it or save the PDF file. It's a good read.

http://www.ushio.com/files/entcatalog3.pdf

http://catalog.gelighting.com/cgi-bi...&subcat=L2-114

Michael Morlan May 28th, 2003 12:37 AM

Many cine fresnels are designed to be lamped down. For instance, the Mole Baby 1K can take a 650w lamp. (Can't remember the specific lamp numbers right now.)

One major advantage to using a larger fresnel is that you're getting a larger light source in the larger fresnel lens, hence slightly softer light than a smaller cousin.

So I say "go for it." Ask your vendor about the range of bulbs that will fit the fixture.

Michael Morlan

Bryan Beasleigh May 28th, 2003 02:30 PM

This whole area is subjective. What is acceptable to one isn't the same for another person.

I A/B'd an Arri 650 fresnel lamped to 300 and an Arri 300, lamped at 300. I bought the 300 over the 650. I wasn't imagining things, I just didn't like the light from the bigger lens. The 300 jumped out and bit me.(Then coyly whispered buy me)

The 650 faired much better staying in the 500/650 watt range. the Arri 650 can be lamped at 650/500/300. The bambino was closer in that it's rated at 300/500. At this point I don't want or need a 650 fresnel. That could change with the wind like everything else in DV.

If I could see the difference then it exists ,even if only to me. That's why there are multiple brands of everything.


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