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-   -   Microbeam early impressions (https://www.dvinfo.net/forum/photon-management/146122-microbeam-early-impressions.html)

Josh Bass March 18th, 2009 03:57 PM

Microbeam early impressions
 
Got my Microbeam today, and toyed around it with it a little bit. I haven't taken any footage yet. . .gotta wait til it's dark and there's someone else here for that, but I can tell you a little about it.

It measures about 5"x3, most of that (except a 1/4" on each side) is LED surface. It feels fairly solidly put together, comes with a swivelly gimbally thingy for your hot shoe mount (and also a screw if that mount is screw-in instead of slide-in)

Also comes with a selection of color correction gels and a little plastic folder to hold them. There's a "warming" gel (looks like it's equivalent to a 1/2 or 1/4 CTO, a "tungsten" (quotes indicate what they wrote on the gel) that I'm guessing is a full CTO, a "diffusion" (seems like Lee 251 or Opal. . .one of those thin ones that you can kinda see through), and a minus green. There's a slot directly in front of the LEDs that holds the gels. You just slip it in. There's no way to secure it on top, meaning if you turn the light upside down it'd just fall out, but I guess you could tape it in or something.

I don't know how much it weighs, but you definitely feel it with a battery on there (I'm using the big cannon battery right now, for an XL2).

That's what I got so far.

Josh Bass March 18th, 2009 09:03 PM

pictures this time
 
7 Attachment(s)
Ok, so I found out I'd be alone tonight, but decided to do these tests anyway, by myself. So I have a series of pictures with different filters on the light, and different white balance settings.

So, these were all taken with a Canon XL2 from about nine feet away, shutter 1/60, open to f1.6, no gain.

Josh Bass March 18th, 2009 09:23 PM

I took so long to edit that last post that now I can't! Hah!

So, again these were all taken with a Canon XL2, using my "low light settings" (low knee, normal gamma, black stretch, everything else should be factory presets) from about nine feet away (since the specs say 85 lux @ 9 feet, I wanted to test that), 30p, shutter 1/60, open to f1.6, no gain, light at full intensity (it has a dimmmer).

"Well, Josh that's a nice block of pictures, but I don't know what any of this means. And by the way, you look like a jackass."

Now, hold on, people; I'm going to explain what each pic is, and the silly faces are for your amusement. And cause no one ever posts tests with silly faces.



So, Top left is tungsten white balance preset, with nothing on the light. Top right is with the diffusion filter only on the light, tungsten white balance preset.

2nd Row (from the top) left is nothing on the light, but daylight white balance preset. 2nd row right is tungsten white balance preset, with the warming filter on the light.

3rd row left is tungsten white balance preset, with both the tungsten filter and the diffusion on the light.
3rd row right is a wideshot so you could see the spread of the light (and my cereal and wheat thins). This is from about 18-20 feet away, daylight preset

bottom pic is tungsten white balance preset with the tungsten filter only on the light.

I'm not too familiar with how the attachments work on this board, so sorry it's not more organized.


So what we see is that the raw color of the light in a tungsten environment is totally unacceptable (though we knew that), but that it's also not quite truly 5600K or else the daylight preset shots would look totally right instead of slightly weird. We also see that the tungsten filter WAY overcorrects, in my opinion, so you'll probably need to experiement and cut your own gels to find the best color correction, or fiddle with manual white balances (one thing I didn't do in these tests). However, the idea should be to match the light's color to the rest of your environment, so that your backgrounds don't look totally different from what the light is actually hitting.

Oh by the way, the slivers of light in the room behind me are from a tungsten source, so perhaps manual WB is the answer? I'm clocking out for tonight, so I guess we'll never know (until the other couple guys on this board that ordered one get theirs, that is).

Man. . .I shoulda tried the tungsten with the minus green. Oh well.

Josh Bass March 20th, 2009 03:16 AM

more "tests"
 
8 Attachment(s)
Okay, there were some things I didn't do in the first battery of tests, so with Patient Girlfriend Watching 30 Rock" as my subject, I did some different settings. All of these were shot at 30p, 1/60 shutter, from 3ft away or so. A note: all manual white balances are done WITHOUT any gels on the light, for better or worse.

Top left - Half CTO on light, indoor wb, f2.8 Top right - half cto, manual wb, f3.4

2nd row left - nothing on light, manual wb, f3.2 2nd row right - quarter minus green, daylight wb, f3.2

3rd row left - screwed up and named it wrong, no idea! 3rd row right - quarter minus green, tungsten filter, indoor wb, f2.4

4th row left - quarter minus green, warming filter, day wb, f2.4 4th row right - warming, manual wb, 3.7

Sorry I didn't correct the aspect ratio on these stills.

So, you'll see I got pretty decent results with a manual white balance, and daylight using just the minus green, so if you're outside those might be useful. Also found out there are two minus greens that come with this light, a half and a quarter. They were stuck together when I first played with the filters. I think the half mg corrects TOO Much. . .gives it a purple cast, to my eye.

Some things I wish I'd tried this time around: quarter minus green and half CTO on an indoor WB, using the tungsten filter and THEN white balancing, using a half CTO and doing the same.

Josh Bass March 20th, 2009 05:29 AM

a few final tests
 
2 Attachment(s)
Ok, it was driving me nuts so I did a few more tests. "Patient Girlfriend Watching 30 Rock" does not live at Bass studios so you are stuck with me as model again. These were all done from about six feet away, open to f1.6, 30p, 1/60 shutter, (by the way, everything I've done has been on -3 gain--I haven't noted that anywhere).

I thought it might be nice to have a tungsten-ish source for reference in the background, so I left the lights on in the storage room/sleep quarters of Bass studios behind me. It's one of those lights that's attached to your ceiling fan, so whatever kinda bulbs those are. . .well, that's what you're seeing the light from. So you can see how other 3200K sources might change with the different white balances I used in these last tests. You can also see what the microbeam does on a pure white surface (those walls in the room with me are basically white). By the way, those walls (the white ones, not the ones in the other room) are about 18-20 feet from the light if you want an idea of how the exposure falls off over distance.


First off, that quarter minus green plus half CTO, with the indoor wB preset I mentioned before? Looks terrible, didn't bother to post a pic of it.

Ok so, left pic is half CTO on the light, manual white balance AFTER the cto was put on. Right pic is a half CTO AND a quarter minus green, manual white balance AFTER the CTO was put on, but BEFORE the minus green. I know that one's pretty complicated.

So, you can see that on the right, my face is a purplish color like I've been choking, but my arm looks okay. What's up with that? the white walls also have slightly purplish tinge. In the left pic, my face looks more natural but my arm's a little green, and the walls have a slightly green tinge. Now, I am a pasty fella always told he needs tan. Well you know what? I don't tan, I burn! The room behind me looks orange on this here computer montor, but on my NTSC monitor it looked like it looked to my eye.

So, I say with this light either of these two options is your best bet to match an indoor environment's lights (more than likely-if they don't have weird mercury lights or something). If you don't mind the slightly purple cast, go with the quarter minus green (or hey, you know what? See if you can dig up some 1/8. . .I think it exists.) If not, go with the no minus green. The half CTO appears to not cut out too much light, but makes a pretty big difference.

I just want to note, if you use half CTO, you'll have to buy it. . .this isn't one of the filters that comes with the light. Also, regarding sensitivity, the XL2 is rated at 320 ASA from what I've read.

Ian Lim March 20th, 2009 07:21 AM

Josh, thanks for taking your time reviewing Microbeam!

Vasco Dones March 20th, 2009 09:50 AM

Thank you so much, Josh!

Vasco

Adalberto Lopez March 20th, 2009 02:13 PM

Hey Josh, thanks for the review. Guess I'm now pretty confident and I'll just go with the Microbeam.

Josh Bass March 20th, 2009 11:51 PM

1 Attachment(s)
Glad I helped someone. I wanted to mention that after attaching and detaching this thing several times, I'm finding the hot shoe mount and i's connected parts to be quite a pain in the ass. Maybe it's an XL2 thing, but it's tough to tighten and loosen the ring against the hot shoe mount without a tool of some sort, and the light seems to turn/spin kinda easily at the at other ring, the part that tightens against the light itself. I'm sure there's an easy fix for these annoyances, but I wanted to let everyone know that (for me) they were there. The screw that tightens the gimbal seems to hold pretty well, however.

There are no real large pics on the Prompter People site, so here's a nice big pic of the actual light, you can see the gimbal/hot shoe piece.

Dana Love March 21st, 2009 06:04 AM

Josh, that's a lot of information. Thanks for sharing it!

John Gyovai March 21st, 2009 12:23 PM

Great job Josh and thanks for all the info.

Now go out there and get some man on the street interviews :-)

Josh Bass March 30th, 2009 01:27 AM

6 Attachment(s)
Okay, at the request of folks in another thread, I did a few more shots to show the spread and reach at gain settings other than -3. These are all done on the XL2 with the same camera preset as the previous pics in this thread.

So, first we have three pics showing the spread on this thing. The first is from about five feet away, the second ten, the third 30-40, since I'm shooting upward at the side of that house (those are trees at the side). The first two are shot at -3 gain, 1/60 shutter, iris at f1.6, 30fps. The last spread pic is +6 gain 'cause I couldn't see much at -3.

The last three pics are inside my casa, and meant to show the "reach" of the light at +3 and +6 gain, since apparently a lot of guys shoot with those settings. These are all about 18-20 ft from the light/camera.

The darkest one is 30p, 1/60 shutter, +3 gain, manual wb through Half CTO and 1/4 Minus green, f1.6 .

The middle dark one is 30p 1/60 shutter, +6 gain, manual wb through Half CTO and 1/4 Minus green, f1.6 .

The brightest one is 30p, 1/30 shutter, +6 gain, manual wb through Half CTO and 1/4 Minus green, f1.6 .

Steve Sobodos March 30th, 2009 08:28 AM

There are great, thanks for taking the time to post these. The spread looks very uniform - no bad hot spot in the center. Also reach doesn't look too bad.

I think I'm going to order one of these.

Josh Bass March 30th, 2009 11:07 AM

No problem. Don't know why it didn't occur to me in my earlier battery of tests to white balance through the minus green and half CTO at the same time. . .seems to solve all the weird color issues at once. You know, like logic would DICTATE that it would. Though it does leave it a little cool compared to not using the minus green.

Steve Berg March 31st, 2009 12:27 PM

Can you tell me a little about the power for this unit. Looks like this uses the standard camera battery. Is there an adaptor? Any idea if you can use an adaptor and use AA battery like the Micolite? I feel like this migh be a better way to go as my HMC150 batterys are over 200 a pop. Someone told me this is the equivalent of a 100W light can you really light up a room/ bride at 15- 18 feet away?

Thanks,


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