Help - I need to shoot 500 paintings with glass on top, only have a 580 and 430 flash

[bocaj]

Ok well they aren't paintings they are merely prints of paintings that have been framed and a glass cover on top of the print ( the glass presents a problem as i dont want a light reflection off of them ). I picked up a job to shoot 500 of these things, and build them a website, and a print catalog so its a pretty big job. SOO my question is.. can i shoot these with just using a 580ex flash and a 430ex? I have a canon xti with an off shoe camera cord. Lightsphere II for the 580ex and an umbrella for the 430ex. Here are two samples i came up with out of the 50 crappy shots i have taken. The prints will be hung on a wall ( shot on location not my place ) but these were just layed on the floor then on a seat just to get my lighting down ( i didnt want to poke big holes in my dry wall )

The image below was shot with it tilted on the ground hence you can see the reflection of the sheet in the glass, this wont be an issue as they will be hung on a wall and shot.


The image below was propped up on a stool but this wont be an issue as it will be mounted on a wall.


Are these images good enough? or should i go ahead and buy two B800's and just figure that as cost of doing business or can i work them with just the two little flashes i have. Im using a 17-40 4L lens... but i also have a sigma 20mm 1.8 if that would be better. Any suggestions as to light placement would be great or anything else. Also what should i charge for shooting 500 different framed prints? The size of the prints range from 12" all the way up to 72"

[FlashZebra]

To rid yourself of reflections you need to get two flash units off the camera and at exactly 45 degrees from the plane of the art (and glass) on either side of the art.

Pull the flash units back enough to get even illumination over the entire art and the illumination from both flash units must be the same.

Try to use at least F/8 to cover for any focusing errors, but do not close down more than F/11 to avoid diffraction problems.

This is going to be hard to do with two Canon flash units as there is no inherent way to fire the units off camera without a third control flash. Canon flash units are very annoying in this respect.

Your 580EX and 430Ex will provide enough power, but getting them to fire is the problem.

For this specific sort of work you have about $650.00 worth of flash gear that is has a built in crutch (lack of any rudimentary off camera manual triggering control).

I suspect two inexpensive basic hotshoe adapters, a PC splitter (sometimes called a spider) and cords might be the least expensive way to go (and flash units set to manual). I am constantly baffled why Canon did not include some sort of basic PC port on their flash units so meat and potatoes work like this can be done without pain or huge expense.

Enjoy! Lon

[bocaj]

Originally Posted by londuck

To rid yourself of reflections you need to get two flash units off the camera and at exactly 45 degrees from the plane of the art (and glass) on either side of the art.

Pull the flash units back enough to get even illumination over the entire art and the illumination from both flash units must be the same.

Try to use at least F/8 to cover for any focusing errors, but do not close down more than F/11 to avoid diffraction problems.

This is going to be hard to do with two Canon flash units as there is no inherent way to fire the units off camera without a third control flash. Canon flash units are very annoying in this respect.

Your 580EX and 430Ex will provide enough power, but getting them to fire is the problem.

For this specific sort of work you have about $650.00 worth of flash gear that is has a built in crutch (lack of any rudimentary off camera manual triggering control).

I suspect two inexpensive basic hotshoe adapters, a PC splitter (sometimes called a spider) and cords might be the least expensive way to go (and flash units set to manual). I am constantly baffled why Canon did not include some sort of basic PC port on their flash units so meat and potatoes work like this can be done without pain or huge expense.

Enjoy! Lon

I have an offshoe cord running to the 580EX that will hopefully allow me to get it in the 45 degree angle i need it to be, and it will wirelessly trigger the 430EX to fire when it does.. so i think i might be ok after all. Thanks for the f stop advice. Should i worry about soft boxes or anything? or just point the flashes directly onto the artwork without any diffusion?

[Lightstream]

Try picking up the Canon ST-E2 if all else fails. It's wonderful to work without cords and will allow you to command both flashes. They can also be set to manual if you prefer consistent lighting. Still cheaper than a set of B800's. Good luck.... '

As Lon said, optical slaves on the Canons, and PC Sync ports would be wonderful. Think it must be a conspiracy to get us to buy the ST-E2. (then again I prefer it to tripping over wires)

[FlashZebra]

Originally Posted by bocaj

I have an offshoe cord running to the 580EX that will hopefully allow me to get it in the 45 degree angle i need it to be, and it will wirelessly trigger the 430EX to fire when it does.. so i think i might be ok after all. Thanks for the f stop advice. Should i worry about soft boxes or anything? or just point the flashes directly onto the artwork without any diffusion?

If you put the flash units at 45 degrees from the plane of the art, and the art surfaces are flat, you should be fine without any diffusion. There will be no reflections in the image. Art surfaces with texture or surface wrinkles are not so forgiving.

One thing I neglected to mention. When you make the actual exposure, turn off all but insignificant room lights, especially overhead lights. You do not want to have them butting into the action with their own set of reflections.

Regarding the "offshoe" cord you cite. If it is the standard Canon cord, it is very likely that it will not be long enough to net the needed 45 degree angle, and still sufficiently away from the artwork to get nice even illumination, especially for such large art.

Another approach:

Since artwork does not move and you can use long exposure times, do not use flash and instead use two inexpensive incandescent flood lights, a tripod, a cable release, and a custom white balance. Those very inexpensive clip on floods with the large aluminum reflectors sold at hardware stores work fine. If you want to get fancy you can use four lights instead of two. With such large art, four might be a good idea.

This approach works fine and avoids all the off camera flash triggering issues.

When things do not move, this creates a lot of photographic opportunities.

If you do not have a cable release, use your self timer.

Enjoy! Lon

[Wilt]

In addition to all the other tips provided:
Set a black hanging cloth, with a hole in it to stick the lens thru. You and the camera remain hidden behind the cloth, so that any bouncing light in the room does not illuminate you so that your reflection is seen in the glass which covers the art you are photographing.

[bocaj]

hmm if i go the clip on flood light route whats the best way to set my white point? Do i just shoot a piece of paper that all the lights are directed to and let my canon rebel xti use that image for the white point? or do i get a kodak grey card and shoot that... i have not had much luck with setting my own white point i always keep it on AWB... damn im such a n00b sumtimes.

[Curtis N]

Normally I say just shoot something white and be done with it, but I think color accuracy is important for a project like this. Better get a gray card.

[bocaj]

any particular grey card i should use? or just go grab one from the photo store and shoot it and then set my white point to that grey card in the camera. or just do all of the post processing work on the RAW images in photoshop. Hmm seems easier to set the white point in the camera... but doesnt the card need to be white? or will the camera set the white balance just fine when it reads the grey card?

[bocaj]

Also i got a couple of these from a while ago:

Craftsman 500 watt Tripod Light with Portable Stand
http://www.sears.com/sr/javasr/produ...seBVCookie=Yes

Will 4 of these work out ok? if so then i think i might be home free

[Curtis N]

An 18% gray card, available at camera shops. Just ask for it, they'll know what you want.
Use it to set a custom WB per the camera's instruction manual, or just shoot it and use your RAW converter to adjust all the shots accordingly. The result will be the same.

4 of those shop lights will be fine if you follow the procedure as Lon described. Wilt's advice is good, too. 2,000 watts might be more than one electrical circuit can handle. Have enough extension cords handy to plug into two different outlets on different circuits.

And you'll have plenty of heat, too.

[Wilt]

pursuant to Curtis' comment about loading the circuit...Watt = Volt * Amp
2000w / 110v = 18.18 amps. Standard household circuit is 15 amps, so you WILL blow the circuit breaker or fuse if you put that much on a single circuit! You would be OK if using a 20A industrial rated circuit.

(Ever notice that consumer hair dryers and electrical space heaters max out about 1500w? That's why!...13.6 max continuous load allows 10% safety margin on 15A household circuit.)

[FlashZebra]

Originally Posted by bocaj

Also i got a couple of these from a while ago:

Craftsman 500 watt Tripod Light with Portable Stand
http://www.sears.com/sr/javasr/produ...seBVCookie=Yes

Will 4 of these work out ok? if so then i think i might be home free

I would not want to be in a room long enough to photograph 500 large pieces of art with four 500 Watt lights (2000 Watts total).

Move it down several several notches. Four 150 Watt or 200 Watt incandescent bulbs will be fine, you can use long exposure times, the art will sit still.

Also, do not use automatic white balance. With AWB you will have a different white balance with every image. This will be worse that having the white balance off just slightly in a consistent manner.

If you have a gray card use it for a custom white balance, if you do not don't sweat this detail use anything white.

Enjoy! Lon

[johneric8]

You dont need near what they are saying.. You can get a pocket bouncer and that will work just as well for your purposes.. trust me I have used one and been paid well for the job..


Oh, I just realised you are shooting a glass surface... sorry..

[JSimonian]

For the group here... What about a circular polarizer to deal with the reflections? Just thought I'd ask, as no one has brought it up. Or would it not help in this situation?