DPChallenge: A Digital Photography Contest You are not logged in. (log in or register) 
 

DPChallenge Forums >> Individual Photograph Discussion >> 1/8000 sec flash sync...HOW?
Pages:  
Showing posts 1 - 16 of 16, (reverse)
AuthorThread
 08/14/2006 11:46:15 PM · #1
I PM the photog on this but does anyone know how to sync D70 to 1/8000 flash sync? I have the SB800 and a D70 but can only go to 1/500.

Shot here:

08/14/2006 11:52:51 PM · #2
Disclaimer: I'm speculating, because I lack some specific knowledge of the camera used...
The photog used a Vivitar 283 flash, and the spray is *stopped* meaning only one firing of the flash. Normally, in order to synch a flash at shutter speeds faster than the rated synch speed of the camera, the flash neds to "strobe" to evenly illuminate the frame as the shutter "slit" passes over the sensor. Here, there's no evidence of that, and I don't believe this flash/camera combination is capable of it
Conclusion: The shutter speed is at or below the camera synch speed. It's the flash duration that sets the exposure at 1/8000. That timing sounds about right. It would vary based on the flash design and power level.

Message edited by author 2006-08-14 23:53:35.
 08/14/2006 11:53:34 PM · #3
Step 1: Sacrifice a goat to the flash gods...

Actually, I didn't think this was possible. I think you just need to have a bright constant light shining on the subject. If not, I'd love to hear how this was done as well.
 08/14/2006 11:58:29 PM · #4
The best way to do this is to use the tape over the contacts trick.

There are two types of contacts on the hotshoe. One type is for flash firing. The other is for I-TTL information communication.

Only the hotshoe bracket tabs (which are metal and give the hotshoe its name) and the center post actually have anything to do with the firing of the flash.

On the other hand, the four (?) other contacts are for specific communication from flash to camera. If the camera can communicate with a flash, it will give you I-TTL functions, aka flash metering. BUT, it will only sync to the max sync speed (1/200 on the D80 recently released).

If there are only two contacts (hotshoe and center post), then the flash acts as a dumb flash.

If you cover the communication contacts, you will fool the camera to think that even your expensive SB800 (or whatever else you use) is a dumb flash.

The D70 will allow flash sync with a dumb flash as fast as it can.

You WILL NOT get any sort of flash metering, so flash output needs to be controlled manually on the flash and/or using the aperture/ISO/distance to subject chart on the back of the flash or in the manual.

For stop motion, this works very well.

For fill flash or for actual flash illumination, this is not very good.

One thing you could do is buy a cheap extra hotshoe mount that effectively negates the extra contacts and use it instead of messy tape. You might have to use the PC-Sync for it, but it would just keep things tidy and organized so you could use i-ttl most of the time, but when you wanted high speed sync photography, you could swap quickly and easily.

FP (flash pulse) capable flashes will not give stop motion, but will also allow high speed syncing WITH i-TTL.

There is a custom function for flash sync speed in your D70 and you can enable this function as well. (I think it's flash sync speed 1/250 (auto FP)) or something like that.

Also see this thread with great links.

EDIT: sorry, started this one before the other replies...

The D70 has a CCD, which has two types of shutter. A mechanical one for up to sync speed and an electronic one specific to CCD type mechanisms.

The FP mode function is not required with a CCD type shutter.

UNLESS it is used for bright condition fill flash. In that case, the output of the flash will need to be a lot higher and could easily become longer than 1/8000. The maximum output of a flash is typically around 1/1000, so you would only get roughly an eighth of the actual flash light under those circumstances. (it would be the same with either type of shutter because the illumination from the flash would in principle be a constant light source from the POV of the camera)

Problems start to arise when the flash is used at really high shutter speeds and the flash duration is LESS than the shutter speed (ie shutter speed 1/8000, flash duration 1/10000), where with a mechanical shutter, you would get flash light clipping and areas of darkness (or non-flash-exposed) in the frame and it would probably look like crap.

This is not an issue for a CCD electronic shutter, so things actually work out on the D70.

Kirbic: Don't quote me on it, but I don't remember the Vivitar 283 as having output duration control... ?

Message edited by author 2006-08-15 00:10:23.
 08/15/2006 12:02:27 AM · #5
I haven't tried this but I've heard from a few people.
Cover all the pins on the flash with tape - leaving only the middle pin exposed. Apparently the flash will fire at speeds above 1/500, but you lose the ability to control the flash - so no TTL.

EDIT: too slow...

Message edited by author 2006-08-15 00:02:50.
 08/18/2006 12:41:01 PM · #6
Sorry, I didn't see this a few days ago. For once Kirbic guested wrong, as my shutter speed was 1/8000 of a second. The D70, in addition to the normal focal plane shutter has a CCD shutter that is capable of flash sync at any speed. Nikon (and I assume third party TTL flashes) disables this functionality by setting the shutter speed to 1/500. As others have stated if you cover all of the contacts except for the center pin it will work with Nikon flashes. I just use the old & great Vivitar 283. WARNING if you are temped to try this with a Vivitar 283, be sure to check the flash sync voltage. A lot of older 283s have sync voltages greater than 300V. Mine is a safe 8 volts.

Another thing to keep in mind is that flash durations can be longer than the selected shutter speed, especially at or near full power. So if you are using a hand held flash meter reading, a calculated exposure, or using the auto thyristor of the flash the exposure can be off.

Message edited by author 2006-08-18 12:47:37.
 08/18/2006 12:44:35 PM · #7
You put the camera on BULB in a dark room.
you set the flash to trigger on noise or motion or some such.
 08/18/2006 12:55:39 PM · #8
Originally posted by eschelar:

Kirbic: Don't quote me on it, but I don't remember the Vivitar 283 as having output duration control... ?


The Vari-Power attachment that allows power to be manually controlled from 1:1 down to 1:32 (or maybe 1:64 as there is a mark past 1:32). It just relplaces the tyristor sensor.
 08/18/2006 12:58:19 PM · #9
Originally posted by Prof_Fate:
You put the camera on BULB in a dark room.
you set the flash to trigger on noise or motion or some such.

Hope this doesn't hijack the thread but I have a question on this statement; is setting the flash to trigger on noise or motion fairly common or does it require special equipment?

For example, I'm considering this flash unit (Sigma EF-500 DG Super ADI TTL Shoe Mount Flash) in the near future. Is it capable of triggering on noise or motion?

Thanks - and sorry for the possible hijack.
08/18/2006 03:06:38 PM · #10
Originally posted by glad2badad:
Originally posted by Prof_Fate:
You put the camera on BULB in a dark room.
you set the flash to trigger on noise or motion or some such.

Hope this doesn't hijack the thread but I have a question on this statement; is setting the flash to trigger on noise or motion fairly common or does it require special equipment?

For example, I'm considering this flash unit (Sigma EF-500 DG Super ADI TTL Shoe Mount Flash) in the near future. Is it capable of triggering on noise or motion?

Thanks - and sorry for the possible hijack.


you almost always need more equipment or electronics to make a flash trigger on anythig but a another flash /
some simple things you just need two wires though ..
Dr. Edgerton football pic. used a wire trigger ...
08/18/2006 04:21:09 PM · #11
When I want to freeze action, I set my camera up on B, use a remote, open the shutter in near pitch black pointed at what I want, have what I want do whatever it's supposed to, than manually hold my flash and fire it when I want at its fastest. Then, close the shutter.

Bam, easy stopped motion.

-Hideo
 08/18/2006 04:25:06 PM · #12
The easiest way to do a shot like that is set up a 1 or 2 second shutter speed and use the flash in the dark. The only exposure you will get is from the duration of the flash.

(easiest if your flash won't high speed synch anyway)


08/18/2006 04:48:50 PM · #13
Originally posted by jmsetzler:
The easiest way to do a shot like that is set up a 1 or 2 second shutter speed and use the flash in the dark. The only exposure you will get is from the duration of the flash.



That was ideal when film was the rule, but with sensor noise if I had the option I'd go for the fash sync. Also with really high sync you could do some shots like we have seen here, like water ballons being busted by arrows etc, outside where you can make a mess and in an area where you can really see what you are doing (ie safely).
 08/18/2006 04:49:40 PM · #14
I can synch to 1/8000" with the Canon 550EX flash using the high speed synch option.
 08/18/2006 05:27:31 PM · #15
Originally posted by hyperfocal:
Originally posted by jmsetzler:
The easiest way to do a shot like that is set up a 1 or 2 second shutter speed and use the flash in the dark. The only exposure you will get is from the duration of the flash.



That was ideal when film was the rule, but with sensor noise if I had the option I'd go for the fash sync. Also with really high sync you could do some shots like we have seen here, like water ballons being busted by arrows etc, outside where you can make a mess and in an area where you can really see what you are doing (ie safely).


I did my balloon shots outdoors with no flash!
 08/18/2006 05:43:43 PM · #16
Originally posted by jmsetzler:
I can synch to 1/8000" with the Canon 550EX flash using the high speed synch option.


You won't quite get the same results. See my first post. As the shutter "slit" passes over the sensor, the flash fires multiple times. the upshot is that the exposure is 1/8000, but only in each "stripe" and the individual stripes will be time-shifted.
I'd also use your first method, reducing ambient lighting and shooting at max (normal) synch speed at small aperture/low ISO to limit ambient light intrusion, and use the flash duration to limit exposure time.
Pages:  
Current Server Time: 09/14/2025 07:21:10 PM

Please log in or register to post to the forums.


Home - Challenges - Community - League - Photos - Cameras - Lenses - Learn - Help - Terms of Use - Privacy - Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 09/14/2025 07:21:10 PM EDT.