PDA

View Full Version : High-Speed Sync for Speed Graphic



AeroK
29-Dec-2019, 23:21
I want to use a strobe in conjunction with the focal-plane shutter in my Speed Graphic. Normally, one uses slow-burn flashbulbs because the shutter has vertically sliding slots -- different widths for different speeds. Regular strobes are way too fast and therefore only expose a small part of the frame.

High-speed sync simulates a slow-burn flashbulb by firing many times in rapid succession while the focal-plan shutter wipes across the film.

My question is: Has anyone figured out to connect the Speed Graphic's flash contacts to a strobe (or trigger) for high-speed sync with anything like Godox or any other strobes?

...doug

Tin Can
30-Dec-2019, 06:09
https://www.bhphotovideo.com/c/product/164971-REG/Paramount_PMBPPF_Female_PC_to_Bipost.html

However they are a tight and hard fit

I think you need to use slow shutter speeds and let the flash stop the action

I sometimes shoot without lights on

Oren Grad
30-Dec-2019, 08:10
Physically connecting the flash should be simple enough with a bipost sync cord. I think what you need to find out is the travel time of the SG shutter curtain at different tension settings compared to the travel time of the small, bladed focal plane shutters in modern SLR and mirrorless cameras for which HSS has been promoted. My guess is that the Speed Graphic curtain will be way too slow, that the HSS flash pulse sequence won't last nearly long enough to cover it. And if it does, the power will probably be so attenuated that it's not especially useful. But it's a great question, I too would like to hear about it if someone has found a way to make it work.

Tin Can
30-Dec-2019, 08:53
Searching, https://news.ycombinator.com/item?id=16107292
https://www.photo.net/discuss/threads/flash-synchronization-in-1-8000-with-nikon-d70.125993/

Don't know OP's plans, need more input

I settle by using Packards and Dial Set shutters at 1/30th with any strobe

Dan Fromm
30-Dec-2019, 09:01
Tin Can has a point.

OP, why must you use your Speed's FPS?

BrianShaw
30-Dec-2019, 09:04
It can’t be worth the effort...

BrianShaw
30-Dec-2019, 09:10
Doug, I seem to recall that (some?) pacemaker graphics had synch contacts on shutter curtain... for FP bulbs. But your talking about retrofitting your Anniversary... right? If so, perhaps you need a second camera. :)

Oren Grad
30-Dec-2019, 09:10
Tin Can has a point.

OP, why must you use your Speed's FPS?

Dan, my guess is that it won't work. But if it did, it would be a welcome option for Graflexes with barrel-mount lenses.

Tin Can
30-Dec-2019, 09:18
Arenít the Speed curtain sync contacts only in one place or opening?

That has messed me up before

BrianShaw
30-Dec-2019, 10:10
Aren’t the Speed curtain sync contacts only in one place or opening?

That has messed me up before

Not sure, but seem to recall some limitations. But don’t have any experience with that feature. A search of a user manual would answer that question. I’ll bet my 1966 PM 3&2 course book would say... will look up later if I can.

AeroK
30-Dec-2019, 10:44
OP, why must you use your Speed's FPS?

I'm using an Aero-Ektar lens without a shutter.

Dan Fromm
30-Dec-2019, 10:47
I'm using an Aero-Ektar lens without a shutter.

There are large Packards, you could mount one in front of the lens. Is 1/25 too slow given ambient lighting?

Re too slow given ambient, one way of dealing with that is to use slower film.

Neal Chaves
30-Dec-2019, 10:48
Just use a leaf shutter with X sync. Enjoy the focal plane shutter with barrel lenses. If you are determined to use the shutterless Aero Ektar with electronic flash, a front mounted Packard as has already been suggested is the best approach.

Tin Can
30-Dec-2019, 10:56
Also setting that combo up. Actually mine is ready but soon changing lens mount

I am sure my 1951 Speed has curtain sync contacts on only one slit as I thought they were NG some years ago

I will be checking that soon







I'm using an Aero-Ektar lens without a shutter.

AeroK
30-Dec-2019, 11:10
Don't know OP's plans, need more input

Thanks for the links to Packard shutters. Might work. Need a bit more studying.

I'm using an Aero-Ektar 178mm f/2.5 barrel lens. Not mounted in a shutter.

AeroK
30-Dec-2019, 11:12
There are large Packards, you could mount one in front of the lens. Is 1/25 too slow given ambient lighting? Re too slow given ambient, one way of dealing with that is to use slower film.

That might work, Dan. 1/25 is probably ok. I'd like the option of faster speeds to manage the ambient light, but 1/25 is better than nothing at all!

AeroK
30-Dec-2019, 11:15
I too would like to hear about it if someone has found a way to make it work.

I need to dig into the wiring of HSS strobes. It's probably not something as simple as a contact closure, but it might be possible to control it with an Arduino or something like that. I fear you're right, Oren -- that HSS won't last long enough for the relatively slow shutter speeds of the focal-plane shutter.

BrianShaw
30-Dec-2019, 11:17
The Pacemaker Graphic and FP bulbs was only for fast shutter speed: 1/250 and higher.

Oren Grad
30-Dec-2019, 12:02
I need to dig into the wiring of HSS strobes. It's probably not something as simple as a contact closure...

It might be. If the HSS setting is made on the flash rather than from the camera's menu, and the exposure mode is set for manual or for AE controlled via on-flash sensor rather than camera-controlled TTL AE, there might not be anything that needs to be communicated between camera and flash other than sync closing. In theory the duration of the HSS pulse sequence might be customized to different camera bodies via some signal through the dedicated flash contacts, but in practice I suspect that it's a fixed parameter.

LabRat
30-Dec-2019, 12:51
The ez, old school way is to use bright hot lights, and use any speeds you can meter...

Steve K

Tin Can
30-Dec-2019, 13:30
I tried 2K's a while ago, no thank you!


The ez, old school way is to use bright hot lights, and use any speeds you can meter...

Steve K

LabRat
30-Dec-2019, 14:05
I tried 2K's a while ago, no thank you!

Hey, Hurrell did it all the time!!!

But the poor subject might be scared of the "interrogation", or be cooked like BBQ...

Steve K

AeroK
30-Dec-2019, 23:35
...if the HSS setting is made on the flash rather than from the camera's menu, and the exposure mode is set for manual or for AE controlled via on-flash sensor rather than camera-controlled TTL AE, there might not be anything that needs to be communicated between camera and flash other than sync closing. In theory the duration of the HSS pulse sequence might be customized to different camera bodies via some signal through the dedicated flash contacts, but in practice I suspect that it's a fixed parameter.

Just a guess, but I would think the manufacturer would design a system in which the strobe was aware of the shutter speed so it didn't have to keep flashing once the shutter was fully closed. Big difference between asking the strobe to cover 1/500 seconds versus 1/8000.

Tobias Key
31-Dec-2019, 05:38
Just a guess, but I would think the manufacturer would design a system in which the strobe was aware of the shutter speed so it didn't have to keep flashing once the shutter was fully closed. Big difference between asking the strobe to cover 1/500 seconds versus 1/8000.

I don't think that is what happens. The shutter always takes the maximum sync speed (say 1/250th) to open then fully close at high speeds. The slit between the shutters (the shutter is never fully open at higher speeds) creates the higher shutter speeds. So the burn of the HSS flash is always 1/250th or whatever but at higher speeds the maximum power is cut as the gap between the shutters narrows. The shutter curtains themselves always travel at the same speed it's the timing of the second curtains release that controls shutter speed. So what you would need to look for is a flash that burns for the amount of time it takes for the the speed graphic shutter to fully open and fully close. I don't know how long that takes with a speed graphic but if it takes 1/30 with a Pentax 67 I would guess it would take a 1/15 or an 1/8 second with a Speed. I don't know where you would find a flash that burns for that long.

Oren Grad
31-Dec-2019, 09:16
Just a guess, but I would think the manufacturer would design a system in which the strobe was aware of the shutter speed so it didn't have to keep flashing once the shutter was fully closed. Big difference between asking the strobe to cover 1/500 seconds versus 1/8000.


So what you would need to look for is a flash that burns for the amount of time it takes for the the speed graphic shutter to fully open and fully close. I don't know how long that takes with a speed graphic but if it takes 1/30 with a Pentax 67 I would guess it would take a 1/15 or an 1/8 second with a Speed. I don't know where you would find a flash that burns for that long.

What Tobias said. The relevant parameter isn't the marked shutter speed, it's the curtain travel time, because that's the duration during which some part of the sensor or film is being exposed.

Tin Can
31-Dec-2019, 09:20
Nikon TTL History
What is TTL? D-TTL? iTTL? (https://www.scantips.com/lights/ttl.html)

AeroK
31-Dec-2019, 09:51
...the shutter always takes the maximum sync speed (say 1/250th) to open then fully close at high speeds. The slit between the shutters (the shutter is never fully open at higher speeds) creates the higher shutter speeds.

That makes sense Tobias. I think you're probably right. Thanks.

...doug

AeroK
31-Dec-2019, 09:58
...the shutter always takes the maximum sync speed (say 1/250th) to open then fully close at high speeds...So what you would need to look for is a flash that burns for the amount of time it takes for the the speed graphic shutter to fully open and fully close.

I'm still on my first cup of coffee for the day, but how about this: Assuming Tobias is correct and that the total duration of the HSS flashes are within a 1/250-second window, then I should be able to use the Speed Graphic's focal-plan shutter at 1/250 or faster. I just need to figure out how to trigger the flash. Might start experimenting today. ...doug

Oren Grad
31-Dec-2019, 09:58
In theory the duration of the HSS pulse sequence might be customized to different camera bodies via some signal through the dedicated flash contacts, but in practice I suspect that it's a fixed parameter.

Thinking about this some more, the frequency and magnitude of the pulses might be tailored to the shutter speed, though any of the sequences should work for a much slower curtain shutter - *if* the overall duration of the pulse sequence is long enough, which it probably isn't. Oh, well.

Oren Grad
31-Dec-2019, 10:03
I'm still on my first cup of coffee for the day, but how about this: Assuming Tobias is correct and that the total duration of the HSS flashes are within a 1/250-second window, then I should be able to use the Speed Graphic's focal-plan shutter at 1/250 or faster.

Again, it's the curtain travel time that matters. This is the HSS total duration you'd need:


...I would guess it would take a 1/15 or an 1/8 second with a Speed.

AeroK
31-Dec-2019, 10:07
Again, it's the curtain travel time that matters. This is the HSS total duration you'd need:

I probably would have figured that out after my second cup of coffee. Thanks again, Tobias!

Oren Grad
31-Dec-2019, 10:16
I probably would have figured that out after my second cup of coffee.

:)