Illuminating glass flower vase from the rear, at night

[brucehughw]

Hi.
With my D7000 and a borrowed SB-700, I wanted to place a flower vase between the camera and the SB-700 (acting as a remote flash), using the remote flash to backlight the stems in the water, the petals, and the water. In the Commander Mode the D7000 apparently uses its own flash to communicate with the SB-700, and the in-camera flash produces specular reflections. Do I need radio transmitters (model suggestions?) to make this setup work? Or is the setup incorrect? I'm looking for that elusive dark background (did this in the evening), and I thought having the flash backlighting the subject would keep the background dark.

Thank you, Bruce

PS Light Science & Magic on the way

[Manfred M]

Bruce - the pop-up flash on the D7000 is causing reflections for sure. It has to fire to communicate with the SB-700 so you will need to prevent light from hitting the vase for your experiment to work.

One thing you could try is placing an opaque reflective surface at a 45 degree angle in front of the pop up flash to ensure that none of the light hits the vase, but enough light is emitted to fire the SB-700. I would test this first before heading down the radio trigger route.

When it comes to radio triggers, I use PocketWizard Flex TT5 tranceivers on my Speedlights and my camera as well at the AC3 Controlller on camera. These are quite expensive, but I'm not sure which less expensive units are compatible.

[Mike Buckley]

Return to your first thread discussing all this stuff about flash. You'll find a post I wrote providing a link to an expensive product that solves your problem regarding the pop-up flash producing specular highlights in the glass. The device blocks all of the light except the infrared beam that transmits the information to the remote flash.

[Mike Buckley]

Dave alerted me that I meant to write that the product is inexpensive, not expensive.

[Dave Humphries]

Dave alerted me that I meant to write that the product is inexpensive, not expensive.

You were supposed to just quietly edit the post Mike - but thanks for the acknowledgement (though none was required).

[brucehughw]

Hi, Mike (and Manfred).

Thanks very much for the additional advice. I recall you mentioning that inexpensive device -- I think it blocks visible light and passes IR. I believe it's this one, and I'll double check in the earlier post. I'll try Manfred's suggestion (the free one) first. I also found the Lighting 101 link in another CiC post, and the author there recommends a simple hot-shoe attachment and 1/8" cable (I know, tripping hazard, but this is all table-top or around-the-table setups) to sync the camera and remote flash. More things to try.

Thanks again, Bruce

Dave alerted me that I meant to write that the product is inexpensive, not expensive.

[Manfred M]

Hi, Mike (and Manfred).

Thanks very much for the additional advice. I recall you mentioning that inexpensive device -- I think it blocks visible light and passes IR. I believe it's this one, and I'll double check in the earlier post. I'll try Manfred's suggestion (the free one) first. I also found the Lighting 101 link in another CiC post, and the author there recommends a simple hot-shoe attachment and 1/8" cable (I know, tripping hazard, but this is all table-top or around-the-table setups) to sync the camera and remote flash. More things to try.

Thanks again, Bruce

Bruce - I assume you are referring to something like this?

http://www.nikonusa.com/en/nikon-pro...mote-cord.html

If you want to control the flash output from your camera, you need something with the Nikon contacts and a lot of the third party stuff does not have this built in, so all you get is the full power flash or whatever you have dialed into the SB-700. I use one of these with my StroboFrame or off-camera hand-held work.

I can almost guarantee you will be cursing the cable in the image and knocking over the vase if you go this way. which is one of the reasons I did not suggest it.

The "dumb" option means you have a synch chord as well as a hot shoe adapter for the camera and flash (the SB-700 does not appear to have a synch cord port). This type of solution tends to be rather tenuous at best as the contacts never seem to work as well as they should, the tripping hazard is well identified and not all hot shoe adapters have a "hot" output that fires the flash.

[Mike Buckley]

a simple hot-shoe attachment and 1/8" cable

Unless your friend can loan them to you, their cost will be far greater than the cost of the device I suggested and a lot more hassle to use.

[Mike Buckley]

By the way, another advantage of the device I suggested is that once you mount it on the camera, you can control multiple remote flash units. I don't even know if it's possible to do that using cables. If it can be done, it will be hugely, relatively more expensive and hugely more of a hassle in every imaginable way.

[brucehughw]

Manfred and Mike,

You've convinced me -- cords are not the way to go. I'll pick up the device Mike mentioned in the previous thread (Nikon SG-3IR) and try that out. If I end up liking flash work, I'll look into radio triggers (or has this already been covered in another thread?).

For backlighting, which I plan to do with the external flash, won't the subject between the camera and the external flash block the IR emitted by the camera, precluding it from reaching the external flash? Or is the IR emitted rather broadly from the in-camera flash, and it's just a question of some reaching the external flash so that it knows to fire? Comments here and elsewhere suggest the subject will not interfere with the IR and the external flash firing, but I'm just wondering if anyone has encountered that.

Thanks again for your advice.

Bruce

[Manfred M]

By the way, another advantage of the device I suggested is that once you mount it on the camera, you can control multiple remote flash units. I don't even know if it's possible to do that using cables. If it can be done, it will be hugely, relatively more expensive and hugely more of a hassle in every imaginable way.

With Speedlights, there is no way. Normal practice is to run a cable to one Speedlight and use it as a master to fire any of the slaves. This is really no longer commonly used as there are so many better alternatives.

If you are looking at studio lights, those that use power packs work that way. A single trigger will fire the power pack with up to four studio lights plugged into it. Each light ran back to the power pack and the output of each light could be adjusted individually. The set was usually a tripping hazard as the cables from the power pack to the lights ran everywhere.

[Mike Buckley]

I've never had a problem with anything blocking the IR signal. As an example, I regularly place a 14" x 21" piece of foam core and a circular diffuser measuring 42" in diameter directly behind the subject and directly in front of the speedlight with the camera pointed directly toward all of them. Yet the signal always reaches the remote flash.

In your other initial thread, Manfred mentioned that when using a large modifier such as a large soft box, he has had issues with the modifier preventing the IR signal from reaching the speedlight or strobe. I regularly use a small strip soft box and have never experienced that issue.

[brucehughw]

Hi, Mike.

Any chance of you including a sketch or image of the setup you describe? I think I'm after something similar, and I don't fully understand the foam core's placement or function.

Thanks! Bruce

I've never had a problem with anything blocking the IR signal. As an example, I regularly place a 14" x 21" piece of foam core and a circular diffuser measuring 42" in diameter directly behind the subject and directly in front of the speedlight with the camera pointed directly toward all of them. Yet the signal always reaches the remote flash.

In your other initial thread, Manfred mentioned that when using a large modifier such as a large soft box, he has had issues with the modifier preventing the IR signal from reaching the speedlight. I regularly use a small strip soft box and have never experienced that issue.

[Mike Buckley]

You'll see the setup and an alternative setup described and explained in Light: Science and Magic once it arrives. The explanation is far better than anything I could provide. Refer to diagrams 7.6 and 7.7 on pages 189 and 191, respectively, of the latest version of the book.

[brucehughw]

Ah, great. The book, which I reserved, arrived today in the library. My own copy should arrive soon.

Thanks for telling me where to look. CiC has very generous members!

[brucehughw]

Hi, Mike.

I just got the book and looked at the figures you cited. Very clever. Looks like a great book. I look forward to learning the material and posting results in CiC.

Bruce

You'll see the setup and an alternative setup described and explained in Light: Science and Magic once it arrives. The explanation is far better than anything I could provide. Refer to diagrams 7.6 and 7.7 on pages 189 and 191, respectively, of the latest version of the book.

[Manfred M]

Hi, Mike.

I just got the book and looked at the figures you cited. Very clever. Looks like a great book. I look forward to learning the material and posting results in CiC.

Bruce

We look forward to seeing the results of your experimentation!

[Marie Hass]

Dear Bruce,

My studio is small and cords are a PIA, especially if you have a flash cord and are working tethered. And sometimes a corded headset if i am on Skype. Next time around, i will try to do wireless everything.

Marie