Small Studio Work

[purephotos]

Hey all, I'm on holidays from school and we have a spare room, so I decided I want to set up a small studio type area so I can expand my photography collection and skills. I have access to a ew bits of gear, such as backdrops, lights, gels, flash units (only small ones, no monoblocks or floorpacks) as well as a large variety of lenses, a D200 and a couple of tripods and diffusers. I am also thinking of making a small light tent.

My main two questions are:

How should I set up my studio for some action shots
and
What are some ideas to get me started.

I have a fair bit of experience with cameras just have a quick look at http://l0stsnypr.deviantart.com/gallery

Thanks in advance all!

-R

[Bunyip]

What do you mean by 'action shots'?

[purephotos]

Action shots such as: Paintball splatter/impact deformation, exploding lightbulb etc.

-R

[Bunyip]

Oh wow! you want to do high-speed stuff? Hmm. I believe that most of that kind of thing is done with a special camera. The trick will be to fire the camera and flash at the point of impact. You have me stumped, I'm admit.

You're going to need some plastic sheets anyway.

[purephotos]

I was thinking just use motor drive and sync it with my speedlight and just keep trying. I've got 500 paintballs and it's not difficult to get more. The light bulbs may be a bit more tricky, but again, probably motor drive. I have pretty good reflexes and I can time things well cause I'm a musician so maybe that will help.

-R

[jev]

What you need for 'high speed' studio photography is a trigger that triggers ;) the flash when it detects something. No special camera or special shooting-skills involved. I'm afraid though you will have to make such a trigger yourself; I'm not aware of anything COTS available. I've made such a trigger a long time ago, never got it to work correctly but I'm tempted to dig up the pieces and see if I can get it to work this time.

[purephotos]

hmm yes. I've seen a few home made IR detectors, perhaps i could wire one of those into a servo motor...I'm not sure how to make it trip the camera except mechanically....

-R

[jev]

Why would you want to trip the camera mechanically? That is asking for trouble...

The trick is to 100% darken the room, open the shutter in bulb and trigger the flash at the right time. You shutter times will be far too long to get a nice action shot.

I'ld say: if you can get an IR detector (better make sure it uses a very narrow beam first!) hook it up to a relay and have that trigger your flash. It ain't rocket science ;).

[Bunyip]

It ain't rocket science ;).

Maybe not, but it's not exactly click-and-giggle either is it?

The strategy sounds good.

[purephotos]

I can do 1/8000th sec shutter, but only sync flash to 1/250 sec. Could you go into more detail for a flash trip? Ie. Hw to build this "relay" I don't know what you mean, or is the relay something you buy?

-R

[kiwi]

I can do 1/8000th sec shutter, but only sync flash to 1/250 sec. Could you go into more detail for a flash trip? Ie. Hw to build this "relay" I don't know what you mean, or is the relay something you buy?

-R

I believe a sound activated trigger is the way to go. I've seen it done really well using these things.

Found this (and heaps of of other link googling)

http://forums.dpreview.com/forums/read.asp?forum=1021&message=16980928

[hoffy]

Its not the flash sync that makes it work, its the flash duration. I have this down as a future project (Yes, I think I am turning into a "gunna").

Some standard "Speedlight" type flashes (Metz) can have a flash duration of aproximately 1/30000 or even quicker. The trick is timing. If you are good, you can even manage by triggering the flash yourself at the right time, just by hitting the test button.

Check out this below with some using info and decent shots:
http://www.dyxum.com/dforum/forum_posts.asp?TID=39296&KW=high+speed

[purephotos]

Thanks for the replies guys! I'll have a look and if anyone else has ideas, please post!

-R

[jev]

I'ld just like to add a little explanation on the "why not using a high-speed shutter instead of flash" question. Not only is a flash much, much faster as hoffy already said, but there is the thing of your camera using a focal plane shutter too.

The technical explanation: the shutter in your camera basically consists of two curtains that travel up and down. When in rest, the first curtain is covering your sensor. When your trigger the shutter, the first curtain opens, thus exposing the sensor. After a set time, the second curtain follows and covers the sensor again, after which both curtains move back to the original position.

The curtains move fast, but they still need some time to move from completely closed to completely open or vice versa. In a modern camera, this takes somewhere between 4 and 5 milliseconds, or 1/250" to 1/200". Do these times seem familiar to you? They should, because they are known as the X-sync time when using flash (as you noticed).

"Now then", you may say: "my camera can make pictures at much shorter timing". The answer to that is simple: in case of an exposure shorter than X-sync, the second curtain starts closing before the first one is completely open. Imagine a crack through which the light moves over the sensor. As a result, there is only a part of the sensor visible at a time.

Now, if you have a fast moving object like a bullet, it depends on how the curtains actually move (in a modern DSLR usually vertically) and where the bullet is when the crack exposes the part of the sensor where your bullet is flying.

There's a second reason you don't want to use a short exposure based on shutter times: you would need a hell of light source to light your scene. You will want to be pretty close to the subject with some DOF. Let's assume you use a 50mm lens on a distance of 100 cm from your subject. With f/8, that would give you a DOF of 12.2 cm. However, with 1/2000", you'ld need to cranck up your lights to generate 17 Ev or 327680 lux. That is as much light as you would get in full sunlight on a beach or in the snow with ISO set at 200. To give you an idea: the recommended office lighting in Australia is 320 lux...

[purephotos]

I already knew of the curtains in a DLSR, but I was hoping that there might be some way to use the fast shutter speed to help. I just tried some photos of a water drop hitting still water at 5 FPS, but no luck so far...I think I need a more powerful flash with shorter strobe times. ATM I'm using an older Nikon SB-25 and it just isn't working, I currently am using full motor drive with synced flash operating at 1/64 output, which the manual says will give me a strobe time of 1/23, 000th sec. I still Can't cleanly get a shot of water hitting water. Any ideas?

-R

[hoffy]

Excellent explanation there Jev!

I have thought of getting one of my electronic engineering mates to see if he could come up with a trigger box....The idea would be to have as close to maximum trigger speeds as possible, but to also be able to adjust those trigger speeds down, to get different effects and to fine tune the shot. Challenges obviously would be the trigger itself (it needs to be fast enough).

I was thinking of the old Bullet through the cards scene that I am sure you have seen before. The way I was thinking of it, was to shoot through 3 or 4 cards, have the trigger set on the first card and with some trial and error (and probably a few decks of cards) get it timed so you could get the shot on one of the middle cards. My biggest concerns are deflection (I would probably use a .22) of the bullet and a suitable location to pull this one off.

[jev]

Challenges obviously would be the trigger itself (it needs to be fast enough).
Nah, that's no challenge. Even when using someting processor based it'll have plenty of time. Maybe next week - it really shouldn't take more than a couple of hours to get something up and running.

[jev]

By chance I found this reference on another forum today: build your own (http://www.hiviz.com/tools/triggers/makeown.htm). There's a lot more on that same website on high-speed photography BTW!

[purephotos]

Thanks for the link! It looks pretty easy so I'll go get thew bits from DSE and try it out. I think I'll try the optical trip first. I tried some stuff last night, but had no luck. Hopefully this will help!

-R