"Mystery Modifier" revealed - DPChallenge Forums

08/03/2006 01:58:56 PM · #1

In the thread LightSphere the best? Show me. one of the devices I tested was called the "Mystery Modifier". There was a bit of interest as to what it is, so I thought others might be interested.

So, at the risk of exposing myself to much ridicule and snickering, I am going to show it here.

First some background. I made it something like 12 years ago in an attempt to apply the principles of soft lighting, as I understood them, to my on-camera strobe. At the time, I was even cheaper than I am now, hard as that may be to believe for those that know me. The materials were a piece of artist's velumn (available at most art supply houses) and a beloved styrofoam 6 pack cooler (sob!). Fortunately they are readily available for a couple of bucks.

After doing some calculations regarding the angle of coverage of my flash (at wide angle) and the placement of my sensor - TTL makes that unnecessary, but you still need to be aware of where your focusing light comes from - I determined how much of the styrofoam cooler to cut off...the final dimensions are 9 1/2"wide x 6 7/8"high x 6"deep.

On the bottom of the cooler (now the back of the modifier) I traced the outline of my flash head as near to the center as the considerations mentioned above would allow and used a box cutter to cut out a hole through which I slip my flash head. This hole should be a fairly tight squeeze. This allows the really quite lightweight box to stay on-flash very securely.

Over the opening of the top of the cooler (now the front of the modifier) I placed a piece of the velumn large enough to fold over the edges about 1/2" and Scotch Taped it firmly in place.

That's it! Here are some shots of it (as well as of my ultra clean office space). The last is taken into a mirror to show the evenness of coverage and just how large an apparent light source it is. I actually measured the light falloff from center to corners when I made it, and although I don't recall the specifics, it was less than 1/2 stop. Overall, the light loss is around 2 1/3 stops, which is slightly higher (1/3 to 2/3 stops) than the other modifiers I have. I would be interested in any measurements of the LightSphere light dropoff in it's various configurations if anybody has them.

front and side

back w/hole

shot into mirror

OK...it IS funky looking. I have only had the nerve to use it in public a few times. But after the tests in the thread I am seriously reevaluating my pride. This unit rocks performance wise. Maybe I can do something cosmeticly to "pro" it up. I have tried spray paint - that doesn't work as it eats the styrofoam. Leather dye surprisingly seems to be neutral to the foam, but black dye looks gray and a bit uneven.

Any ideas?

kyebosh

Canon EOS-20D

Canon EF 80-200mm f/2.8L

08/03/2006 02:00:50 PM · #2

ha! i totally guessed it!

Canon RF 24-70mm f/2.8 L IS

08/03/2006 02:03:44 PM · #3

lol I have to put up some pics of my own homemade lightsphere when I get home now..... I will post some shots of my homemade lightsphere later today

I just order the lightsphere it should be here soon

kirbic

Canon EOS R5

08/03/2006 02:11:15 PM · #4

Looks great, LOL!
You can paint it, but avoid paints that have a solvent other than water. Styrene reacts strongly to almost all hydrocarbon-based solvents.
There are some water-borne spray paints, but you could just brush on a water-based paint as well.
One other thing to consider: line the box with aluminum foil. Crinkling it up a bit and re-stretching before application to make it less specular might be a good idea.
The aluminum foil should eliminate light escaping from the box, increasing efficiency. It should not impact the apparent source size.

08/03/2006 02:11:19 PM · #5

Originally posted by kyebosh:

ha! i totally guessed it!

Well...not totally, but you were on the right track! The box has some real advantages over simply "holding a piece of paper in front of the flash..."

08/03/2006 02:13:06 PM · #6

Originally posted by kirbic:

Thanks for the very good suggestions...the best I could come up with is pasting a bunch of beer bottle labels all over it!

kyebosh

Canon EOS-20D

Canon EF 80-200mm f/2.8L

08/03/2006 02:34:12 PM · #7

Originally posted by jemison:

Originally posted by kyebosh:
ha! i totally guessed it!

Well...not totally, but you were on the right track! The box has some real advantages over simply "holding a piece of paper in front of the flash..."

yeah but my 2nd guess was almost exactly on :-D

This is a bit longer than others in terms of front to back thickness than one's i've seen made. and one i saw was really wide and tall, maybe twice as big. The guy had gotten some really nice lighting with his off camera flash cable and the diffuser.

DjFenzl

08/03/2006 02:35:43 PM · #8

this would make shooting i-TTL impossible wouldn't it - since the light sensors on the front of the flash would be blocked?

hyperfocal

Nikon D7000

Nikon MF 105mm f/2.5 AIS

08/03/2006 02:42:01 PM · #9

Originally posted by Megatherian:

this would make shooting i-TTL impossible wouldn't it - since the light sensors on the front of the flash would be blocked?

The sensors on the SB-600 & 800 are on the side, so there shouldn't be a problem.

Message edited by author 2006-08-03 14:42:17.

08/03/2006 02:43:55 PM · #10

Originally posted by kyebosh:

Originally posted by jemison:

Originally posted by kyebosh:
ha! i totally guessed it!

Well...not totally, but you were on the right track! The box has some real advantages over simply "holding a piece of paper in front of the flash..."

yeah but my 2nd guess was almost exactly on :-D

This is a bit longer than others in terms of front to back thickness than one's i've seen made. and one i saw was really wide and tall, maybe twice as big. The guy had gotten some really nice lighting with his off camera flash cable and the diffuser.

Hmmm...larger surface and closer to the flash? Either he has a really wide angle flash head or he is getting a big hot spot. You can do the calculations by finding out what the angle of coverage of your particular flash is and projecting it in front of the flash. As I described that is what I did, which led to the particular dimensions I used...anything larger (at the same distance from the flash) or the same size closer to the flash would not have sorked as well, producing a hot spot. I thought it was important to try to achieve even illumination of the front window.

Sigma 30mm f/1.4 EX DC HSM for Nikon

08/03/2006 02:48:56 PM · #11

Originally posted by Megatherian:

this would make shooting i-TTL impossible wouldn't it - since the light sensors on the front of the flash would be blocked?

Dan,

Not sure exactly what i-TTL is, but the whole idea of TTL flash, as I understand it, is that the exposure info is taken from the film-plane, which is unaffected by whether or not the sensor on the flash is covered. FWIW when I originally built it I took that into consideration...although it covered my on-flash sensor, My OM4 had TTL so it was not a problem. Where it could be a problem is with Auto flash mode, which utilizes the on-flash sensor.

Correct me if I'm wrong here someone.

ShaneBlake

Nikon D7100

08/03/2006 02:49:43 PM · #12

Originally posted by kyebosh:

ha! i totally guessed it!

bah... i figured it would be a milk jug...

DjFenzl

08/03/2006 05:30:00 PM · #13

Originally posted by jemison:

Originally posted by Megatherian:
this would make shooting i-TTL impossible wouldn't it - since the light sensors on the front of the flash would be blocked?

Dan,

Not sure exactly what i-TTL is, but the whole idea of TTL flash, as I understand it, is that the exposure info is taken from the film-plane, which is unaffected by whether or not the sensor on the flash is covered. FWIW when I originally built it I took that into consideration...although it covered my on-flash sensor, My OM4 had TTL so it was not a problem. Where it could be a problem is with Auto flash mode, which utilizes the on-flash sensor.

Correct me if I'm wrong here someone.

right, nevermind, I'm having a sand-in-the-head day and not thinking straight.

Art Roflmao

Canon EOS-6D Mark II

Nikon AF-S Nikkor 50mm f/1.4G

08/03/2006 06:02:04 PM · #14

;-)

Tim

Nikon D300

08/03/2006 06:55:42 PM · #15

Originally posted by jemison:

yes, you are wrong actually. Thats how TTL worked for film cameras but not for the new digital setups. I'm talking Nikon here but I assume that the others are the same, the TTL with my SB 800 is done with a short preflash and metered off a sensor in the front of the flash unit - not the film plane.

violinist123

Canon EOS-6D

Canon EF 24-70mm f/2.8L USM

08/03/2006 06:59:04 PM · #16

Weird that it is termed TTL then (Through The Lense).

Tim

Nikon D300

Nikon AF-S Nikkor 50mm f/1.4G

08/03/2006 07:11:55 PM · #17

Originally posted by routerguy666:

Weird that it is termed TTL then (Through The Lense).

the manual calls it dTTL or something like that, I'm at work so I can't really flick through it and find the exact term. I suppose I could google it but thats probably even more slack than reading fourms at work.

dwterry

Canon EOS-1D Mark III

Canon EF 24-70mm f/2.8L USM

08/03/2006 08:07:26 PM · #18

Originally posted by dr_timbo:

Are you sure?

Canon's e-TTL uses a pre-flash as well, but the metering is done through the lens, just as the name implies.

Edit: However, the comment about the measurement being taken on the film plain is wrong (and probably applies to the film days). The exposure measurement from these flashes comes before the shutter opens.

Message edited by author 2006-08-03 20:14:38.

Nikolai1024

Nikon D300

Nikon AF Zoom-Nikkor 24-85mm f2.8-4.0D

08/03/2006 08:14:40 PM · #19

Originally posted by dwterry:

Originally posted by dr_timbo:
yes, you are wrong actually. Thats how TTL worked for film cameras but not for the new digital setups. I'm talking Nikon here but I assume that the others are the same, the TTL with my SB 800 is done with a short preflash and metered off a sensor in the front of the flash unit - not the film plane.

Are you sure?

Canon's e-TTL uses a pre-flash as well, but the metering is done through the lens, just as the name implies.

I use a on flash softbox that covers that sensor sometimes. That leads me to conclude that metering is done by camera while flash sends out the pre flashes.

Nick

08/03/2006 09:00:21 PM · #20

Originally posted by dr_timbo:

Originally posted by jemison:

Originally posted by Megatherian:
this would make shooting i-TTL impossible wouldn't it - since the light sensors on the front of the flash would be blocked?

Dan,

Not sure exactly what i-TTL is, but the whole idea of TTL flash, as I understand it, is that the exposure info is taken from the film-plane, which is unaffected by whether or not the sensor on the flash is covered. FWIW when I originally built it I took that into consideration...although it covered my on-flash sensor, My OM4 had TTL so it was not a problem. Where it could be a problem is with Auto flash mode, which utilizes the on-flash sensor.

Correct me if I'm wrong here someone.

yes, you are wrong actually. Thats how TTL worked for film cameras but not for the new digital setups. I'm talking Nikon here but I assume that the others are the same, the TTL with my SB 800 is done with a short preflash and metered off a sensor in the front of the flash unit - not the film plane.

To tell the truth, I can't say definitively one way or the other. My experience shows that the metering is done in-camera, through the lens, though most likely not actually at the "film plane', which as David points out is an old film days terminology. Canon's literature is totally lacking in explaining how the ETTL works, but the Mystery Mod that I use on occasion covers the "sensor" and the TTL still seems to work fine. I am also a bit mystified as to how a sensor on the flash itself could account for FEL metering on various focus points in the viewfinder. I think that the evidence points pretty strongly in the direction of the flash exposure being controlled in-camera, atleast for Canon, but I'm going to study a bit more to see if I can find out.

08/03/2006 09:19:09 PM · #21

with flash and homemade lightsphere

with fllash but without homemade lightsphere

no flash at all

crayon

Samsung Galaxy S24 Ultra

08/03/2006 09:22:56 PM · #22

I thought he had used a lampshade or something...

08/03/2006 09:30:20 PM · #23

Originally posted by digitalpins:

here is my homemade lightsphere I use on my sigma 500 flash, Sorry for the crappy pics they were the first ones i took right after I made it, so I am still playing around with it and doing some testing.

with flash and homemade lightsphere

with fllash but without homemade lightsphere

no flash at all

Ryan, try doing some tests where the flash is the only (or at least the main) light-source...even better, try the setup in the first message in this thread and post your results there.

08/03/2006 09:34:49 PM · #24

ok i will keep testing when I get a chance I will post some pics