[Digitalis]

I'm impressed, £10000 of equipment to demonstrate what I achieved with a camera worth £15. See thread 37.

except I got a pentax K5IIs to synch at 1/250th, which considerably harder than getting a Cosina C1 to sync beyond its normal speed.

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Last edited by Digitalis; 06-22-2013 at 06:11 PM.

[pentasonic49]

Regarding flash duration, my Sigma EF-430ST which predates PTTL So will not work with my MZS or digital cameras runs between 1/100 and 1/30000 so they are being honest like Metz.

[pentasonic49]

Regarding flash duration, my Sigma EF-430ST which predates PTTL So will not work with my MZS or digital cameras runs between 1/100 and 1/30000 so they are being honest like Metz.

I have just had a thought regarding getting the K5 to sync above 1/180. Using a HSS capable flash and manual aperture settings to underexpose a light coloured wall and triggering a short duration additional flash using one of the light activated triggers which fires within a few microseconds of the first of the HSS strobe.This may work, I will search in my junk for an ancient trigger that I havn't seen for years to test out my theory.

[pentasonic49]

I have just had a thought regarding getting the K5 to sync above 1/180. Using a HSS capable flash and manual aperture settings to underexpose a light coloured wall and triggering a short duration additional flash using one of the light activated triggers which fires within a few microseconds of the first of the HSS strobe.This may work, I will search in my junk for an ancient trigger that I havn't seen for years to test out my theory.

I tried three different remotely triggered flashguns without success. The flashes fired but in most cases there was probably a delay between the light sensor seeing the first flash and it triggering the second flash. Even trying all the available settings failed. I don't have any specifications for the trigger to show what it's delay is. Perhaps someone could get this method to work. I have only one flashgun which works on HSS and that is also the only one which has full manual control.

[Anvh]

Regarding flash duration, my Sigma EF-430ST which predates PTTL So will not work with my MZS or digital cameras runs between 1/100 and 1/30000 so they are being honest like Metz.

Flashes that can do hyper syncing are often slower because they work better with hypersyncing then.

HSS does not strobe actually, i also thought that but it isn't true.

When you look at the amount of light a flash give you have a deep spike and then fall of quickly but the fall off will slow down.
What HSS do is not not capture all the light, or the peak of the light but it delays the exposure. The exposure goes off when the light of the flash settles down and you basicly only just use the "after glow" of the flash.
So a flash with long flash duration actually has a shallow (brighter?) after glow.

[maxfield_photo]

HSS does not strobe actually, i also thought that but it isn't true.

When you look at the amount of light a flash give you have a deep spike and then fall of quickly but the fall off will slow down. What HSS do is not not capture all the light, or the peak of the light but it delays the exposure. The exposure goes off when the light of the flash settles down and you basicly only just use the "after glow" of the flash. So a flash with long flash duration actually has a shallow (brighter?) after glow.

There are actually two methods of syncing above max sync, and I think you may be confusing the two, or at least the names.

High Speed Sync or HSS (what Nikon now calls FP or Focal Plane sync) does indeed produce a stroboscopic effect which pulses for the entire time that the shutter curtains are in motion, 1/180th of a second in the case of Pentax. This allows the entire frame to be illuminated, but by separate bursts.

Hypersyncing has no acronym to my knowledge and is not a standard option for the Pentax system. Hypersyncing utilizes the long tail of a single powerful burst to provide light while the curtains are in motion. Shutter timing comes into play, because as you say, the peak of the burst isn't captured, otherwise part of the frame would be brighter than the rest, so the first curtain only begins it's movement after the peak of the flash. I know Pocket Wizard offers hypersyncing mode for Canon and Nikon systems with their Flex TT5 recievers, but either they don't know the timings for the Pentax system, or more likely, they know them but deem such a trigger system commercially unviable.

What may be confusing is that some older Pentax film cameras had an "FP" sync port for syncing with flash bulbs or older flash guns that used that method of timing. But that FP sync and Nikon's FP sync, which is really HSS, are different.

[JimJohnson]

When reading maxfield_photo's explanation, when he got to hypersyncing, I was immediately reminded of flash-bulb synchronization ... and read further to see he mentioned just that. I have a YashicaLM TLR that offers both types of flash synchronization, only flash-bulb sync is called "M" versus "X". I also have a Kodak35 rangefinder that I had converted to X-sync many years ago.

In my earlier photography days I tried using an electronic flash on an older, cheap TLR meant for flash-bulbs. I got exactly what maxfield_photo describes .... the flash would fire just before shutter opened and the only artificial light on my negatives was the tail of the the flash. Needless to say, my negatives were extremely thin.

[Anvh]

Glad to stand correct =]

[pentasonic49]

My test with HSS triggering a second flash optically may have been doomed to failure If the HSS flash was triggered before the shutter opened. Without an adjustable optical trigger the slave may have fired prematurely. As regards hypersyncing, my Metz 48-af2 at full power is 1/125 which would work with shutter blinds taking only 1/180 to run across the sensor plus allowing for the shake reduction extra couple of mm.

[pentasonic49]

My test with HSS triggering a second flash optically may have been doomed to failure If the HSS flash was triggered before the shutter opened. Without an adjustable optical trigger the slave may have fired prematurely. As regards hypersyncing, my Metz 48-af2 at full power is 1/125 which would work with shutter blinds taking only 1/180 to run across the sensor plus allowing for the shake reduction extra couple of mm.

Does anyone remember the top of the range Minolta 35mm camera which had 1/12000 sec shutter and flash sync of 1/300?

[maxfield_photo]

1/125 is probably a bare minimum flash duration for hypersyncing with a 1/180th shutter, and it still may be too quick. The catch is you don't want to capture the first... oh 30% or so of the flash because if you do, the top and bottom of your frame will receive different amounts of light. You really need the flash to fire in advance of the shutter to avoid black bars, but if you were willing to crop them out, a 1/125th t.1 duration might work. The black bar will take care of much of the unevenness caused by the flash's peak intensity. (I think, you might also see if setting the flash gun to rear curtain sync has any effect.)

What you need is a remote that will trigger both the flash and the camera, the Cactus V5 should work, but possibly others too. You would set up the camera, preferably on a tripod, with the wireless reciever unit plugged into the cable release port on the camera. You'll want to start with a just-above-sync speed like 1/250h. Then put a flash on the hotshoe of the transmitter unit, and set it to manual, and full power. Then just point the flash at your subject and use the test button on the transmitter to fire both the flash and the shutter of the camera.

You'll need to use aperture and ISO to adjust your exposure, but you can think of the flash as a continuous light source, just one that you can't meter, so it will take some trial and error. If there is still some unevenness of exposure in the frame, you might be able to fix it in post by using a gradient mask on an exposure layer to counteract the variation caused by the flashes tail. Photographing a gray card, and then flipping the image to negative should give you a perfect mask that you can then save and use on all your images taken at that shutter speed.

This is all kind of theoretical, but I'll test it out soon. I'm just missing a subminiphone adapter.

[pentasonic49]

1/125 is probably a bare minimum flash duration for hypersyncing with a 1/180th shutter, and it still may be too quick. The catch is you don't want to capture the first... oh 30% or so of the flash because if you do, the top and bottom of your frame will receive different amounts of light. You really need the flash to fire in advance of the shutter to avoid black bars, but if you were willing to crop them out, a 1/125th t.1 duration might work. The black bar will take care of much of the unevenness caused by the flash's peak intensity. (I think, you might also see if setting the flash gun to rear curtain sync has any effect.)

What you need is a remote that will trigger both the flash and the camera, the Cactus V5 should work, but possibly others too. You would set up the camera, preferably on a tripod, with the wireless reciever unit plugged into the cable release port on the camera. You'll want to start with a just-above-sync speed like 1/250h. Then put a flash on the hotshoe of the transmitter unit, and set it to manual, and full power. Then just point the flash at your subject and use the test button on the transmitter to fire both the flash and the shutter of the camera.

You'll need to use aperture and ISO to adjust your exposure, but you can think of the flash as a continuous light source, just one that you can't meter, so it will take some trial and error. If there is still some unevenness of exposure in the frame, you might be able to fix it in post by using a gradient mask on an exposure layer to counteract the variation caused by the flashes tail. Photographing a gray card, and then flipping the image to negative should give you a perfect mask that you can then save and use on all your images taken at that shutter speed.

This is all kind of theoretical, but I'll test it out soon. I'm just missing a subminiphone adapter.

It must de difficult to get a number of strobe pulses to just overlap without causing horizontal bands across the picture.

[maxfield_photo]

It must de difficult to get a number of strobe pulses to just overlap without causing horizontal bands across the picture.

I'm sure it is, but that's a concern for the engineers when they attempt to implement HSS. But what I was describing is a possible way to achieve a partial frame sync on a Pentax DLSR using the theory behind hypersyncing.

HSS and Hypersyncing are radically different approaches to achieving the same goal.

[awaldram]

Daylight killing power. Higher sync speeds make your flash effectively stronger when trying to balance with ambient light. Things like ND filters, or stopping down, or lowering your ISO will tame the daylight too, but will adversely affect your flash power in so doing. Shutter speed is a freebie.

Given most flashes at full power deliver t1 figures in the 1/125 region then having a faster sync speed to kill sun is more myth than reality.

[Digitalis]

Daylight killing power. Higher sync speeds make your flash effectively stronger when trying to balance with ambient light. Things like ND filters, or stopping down, or lowering your ISO will tame the daylight too, but will adversely affect your flash power in so doing.

For professional portraiture assignments I just use an Elinchrom Quadra RX for outdoor daylight flash work - it is easy to overpower the sun with a good 1200 WS flash head. However In the studio, high flash sync speeds are not really needed.