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Old December 29th, 2008, 06:36 PM   #1
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RIFA 88 Photometrics

All the talk of lighting recently, and my upcoming shoot, got me in the mood to do some testing. So I thought I'd share the results with the community.

Over the holiday, I bought 4 more 100w 5500k CFL bulbs from Home Depot, and a number of 2-to-1 adapters.

So I had a total of 6 bulbs in the fixture, and placed it 10ft from a blank wall, and measured the light output both with and without the front diffuser.

With Front Diffuser = 19.6FC @ 10ft
Without Front Diffuser = 34.8FC @ 10ft

So at typical 5ft operating distances for interview, the fixture is giving off nearly 80FC with the front diffusion on, and nearly 140FC without the diffusion.

According to the Panavision here (Table of Exposure for Motion Picture film stock)

If we rate our cameras at ASA 320 (like I do for my EX1 at -3db) we are at ~T2.0 at 10ft with the diffuser on, and T2.8 with it off. At 5ft, we are just above T4 with the diffuser and nearly T6 without!

I took some photos of the bulb configuration but I'll have to wait until I get home later tonight to attach them.

After this testing I have to reiterate my comments, that the 3-lamp fluorescent fixtures for this light transforms it from a nice softbox into a wonderful cinematographers tool. Anyone with basic sewing skills could easily make their own front diffussers with some black canvas strips, 4 grommets, and some grid cloth or other diffusion material. To get really fancy (and I may do this myself) you could make the diffusion material attach with velcro all the way around and have instant control of the softness of the light

Terrific solution.
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Old January 3rd, 2009, 07:51 PM   #2
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Perrone - just thought I'd drop in here with a quick note to thank you for your posting to these forums and your detail when doing so. I'm in the process of planning a lighting purchase probably for early February primarily for interview use (but with the hopes of also using it for narrative shorts as well where possible).

Your post here as well as your post in this thread have really been a big help and have sold me on the Rifa and the MR Baby 1k as my primary lights, along with the value of not putting off the purchase of proper grip gear.

Thanks again, and please - keep it up! :)
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Old January 5th, 2009, 02:05 AM   #3
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Are you use the eX sockets in the Rifa 88?

I have a couple of Rifa 88's and wondered if it would be worth upgrading them to the new eX sockets.

Thanks!
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Old January 5th, 2009, 03:04 AM   #4
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Yes, I am using the EX sockets. The FloX3 accessory in the EX.
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Old January 6th, 2009, 12:53 AM   #5
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Can you guys clarify something for me here? You're asking about the "eX" sockets - I'm assuming you mean the sockets that are part of the Rifa-88 lamp itself - so Perrone, you have the Rifa-88 -> FloX3 -> Std fluorescent lights, or as I've heard you mention in another thread: Rifa-88 -> FloX3 -> Light Doubler (from Home Depot) -> Std fluorescent lights?

I guess I'm a little confused by Jack's post asking about upgrading his Rifa-88's to the eX sockets - is that something you have to buy separately from the Rifa-88 purchase itself?

This is the only thing I was thinking Jack might be talking about, but not really sure what the purpose of it is:

Lowel | Rifa eXchange 1000W Module | TH-X1000 | B&H Photo Video
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Old January 6th, 2009, 12:58 AM   #6
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Quote:
Originally Posted by Ryan Mitchell View Post
Can you guys clarify something for me here? You're asking about the "eX" sockets - I'm assuming you mean the sockets that are part of the Rifa-88 lamp itself - so Perrone, you have the Rifa-88 -> FloX3 -> Std fluorescent lights, or as I've heard you mention in another thread: Rifa-88 -> FloX3 -> Light Doubler (from Home Depot) -> Std fluorescent lights?

I guess I'm a little confused by Jack's post asking about upgrading his Rifa-88's to the eX sockets - is that something you have to buy separately from the Rifa-88 purchase itself?

This is the only thing I was thinking Jack might be talking about, but not really sure what the purpose of it is:

Lowel | Rifa eXchange 1000W Module | TH-X1000 | B&H Photo Video
Of course, with another quick search on the Lowel website I think I found the answer. The link I have above is just another lamp head (minus the bulb) to replace the one that comes with the EX88, for example. I can also get the smaller lamp head to accommodate lamps under 500W. So Perrone, you just have the FLO-X3 going right to the Rifa socket, and either the flouro bulbs or your 2-in-1 splitter in the FLO-X3.

As for Jack's question about upgrading, I'm assuming he's talking about getting the FLO-X3 accessory, not some other adapter that he needs to have...

Sorry for the confusion.
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Old January 6th, 2009, 01:06 AM   #7
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Quote:
Originally Posted by Ryan Mitchell View Post
I guess I'm a little confused by Jack's post asking about upgrading his Rifa-88's to the eX sockets - is that something you have to buy separately from the Rifa-88 purchase itself?
Pre-eXchange system Rifa's came with a different mount that only allowed for tungsten lamps. The eX system allows for a quick change from tungsten to fluoros and requires an upgrade on older Rifa's. EX Rifa's have the new socket that can facilitate the usage of your choice of several lamping options.

Lowel | Rifa eXchange Fluorescent 3- Lamp Module | FLO-X3 | B&H is the Flo3 being referred to.
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Old January 6th, 2009, 01:18 AM   #8
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The Rifa lights were originally sold without being able to exchange the lamp heads. The new Rifa's have the "Exchange System", and allow the lampheads to be changed with a quick release.

The Rifa 88 comes standard with a 1000w lamphead and a 1000w tungsten bulb that goes in that lamp head. The Flo-X3 is a different lamphead. You can simply pop off the 1kw lamphead, and pop on the FLO-X3. This is what I do. The FLO-X3 has 3 sockets that take common sized Edison base bulbs. I recently bought some doublers. I screw those into the 3 sockets on the FLO-X3, so that I eventuallly end up with a configuration where I can place 5-6 100w equivalent CFL lamps.

Does this make more sense?
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Old January 6th, 2009, 06:55 PM   #9
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I promised photos so...
Attached Thumbnails
RIFA 88 Photometrics-rifaconfig_wide.jpg   RIFA 88 Photometrics-rifaconfig_closeup.jpg  

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Old January 7th, 2009, 09:20 AM   #10
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Quote:
Originally Posted by Perrone Ford View Post
The Rifa lights were originally sold without being able to exchange the lamp heads. The new Rifa's have the "Exchange System", and allow the lampheads to be changed with a quick release.

The Rifa 88 comes standard with a 1000w lamphead and a 1000w tungsten bulb that goes in that lamp head. The Flo-X3 is a different lamphead. You can simply pop off the 1kw lamphead, and pop on the FLO-X3. This is what I do. The FLO-X3 has 3 sockets that take common sized Edison base bulbs. I recently bought some doublers. I screw those into the 3 sockets on the FLO-X3, so that I eventuallly end up with a configuration where I can place 5-6 100w equivalent CFL lamps.

Does this make more sense?
Thanks Shaun and Perrone - is sure does. The cloud of confusion in my mind has been disspelled. At least on this topic. :)
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Old January 7th, 2009, 09:24 AM   #11
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Originally Posted by Perrone Ford View Post
I promised photos so...
That's great, Perrone, thanks! How much of a hassle is it for you to break down and store the lights after a session? It seems like it's a little tight in there, and you'll have to unscrew each lightbulb and store them in what I think you said was a tupperware container afterwards.

Also, one question I have about flouro's is how to rate the amount of light they give off comparable to the 1000W tungsten that you'd usually keep in there for the EX88? Knowing the inverse-square law of lighting distances as well as the heat (or lack of heat) advantage of flouro's, is there any time that you instead back the light off a bit and use the tungsten 1000W bulb, or is the flouro set up you have just as bright in the end?
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Old January 7th, 2009, 09:50 AM   #12
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I'm never in a hurry, so the extra 5 minutes is no big deal. In fact, these save me time over the time it would take the 1k lamp to cool off enough to fold up the Rifa.

These do not give off as much light as the 1k for sure. But the point of a softbox is to be close to the subject. The 1k is overkill for any work I do. I've been fine using the flox3 with just three bulbs until now.

If I really need a BIG source with punch, I use the silks with a larger fixture.
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Old January 8th, 2009, 12:20 AM   #13
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Perhaps a stupid question, and sorry for what seems like an endless barrage of them, but why use silks instead of something like a Chimera - do silks diffuse less so you basically get a large light source (but need to use it on something bigger than a 1k for a large light)?

I understand the value of the EX88 with flouro's for one-shot or two-shot interviews, but when would you instead think about using silks with a larger fixture, and is that larger fixture something other than your EX88 with its 1k tungsten bulb?
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Old January 8th, 2009, 01:01 AM   #14
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Not a stupid question at all, and I'm glad you are asking them. Helps me by explaining, and will likely help others down the road.

A Chimera requires a speedring and a light source. And even at that, it has significant limits on how large it can be. With a silk, I can light the front of a building if I so choose. There is a lovely shot in ASC magazinne of a silk being used on the set of Casino Royale I believe, or perhaps it's Van Helsing. But the silk (and that is a generic term for a frame with diffusion material) looks to be 30x30 or so. Just MASSIVE.

In terms of when to use large sources, that depends on what you are trying to light. For my upcoming shoot, I will need to light a building rotunda, and a classroom. This is when a Chimera would fall down. I'll be pushing about 4k through silks to get nice smooth light for this. The Rotunda will likely see a 2k up high emulating sunlight, and another 2k on the floor giving general light on the talent. If I had a 10k I'd use it, but I don't. The classroom scene will probably see a 2k bounced off the ceiling to emulate overhead lighting, but I'll soften it first, and then a couple of 1ks through silks to give some frontal lighting to the scene.

Silks are terrific when you aren't worried about spill, as they are essentially uncontrollable. But you can color balance the fixture, and you can get nice spread with them. So that's how they are used.
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Old January 12th, 2009, 08:50 PM   #15
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Thanks, Perrone - that really helps. It sounds like having silks is a good general tool and perhaps a Chimera for smaller applications when you need controllable light in a smaller space (i.e. interviews).

Is there any sort of things one needs to look for in silks? Any sort of accessories that you need to mount silks on the lights, or do they usually come with all necessary mounting hardware?

It's amazing how my lighting budget seems to be getting bigger and bigger as I read more and more... I blame you, primarily. :)
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