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10-16-2016, 01:23 AM   #16
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Ok. I see, sorry.... So in fact when in HSS mode it is the exposure time (eg 1/2000) that impacts on the motion freezing. Whereas longer times than the max sync it is the flash burst that has that impact .... You can get a double effect too, with flash frozen outlines and blurred effects around that. I think some people refer to this as ' dragging the shutter'.

I wonder though if with HSS the freezing effects are the same as without flash? Just thinking that even though the exposure is very short, there is a moving light passing over the whole frame ..... Regardless of the time value set this moving light (the HSS flash) takes 180th sec to pass over the whole frame (the time the moving slit takes to complete its run over the frame) ..... So. would this actually produce a more blurry effect than the same image and subject movement without any flash ...?

10-16-2016, 05:55 AM   #17
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QuoteOriginally posted by mcgregni Quote
I wonder though if with HSS the freezing effects are the same as without flash? Just thinking that even though the exposure is very short, there is a moving light passing over the whole frame ..... Regardless of the time value set this moving light (the HSS flash) takes 180th sec to pass over the whole frame (the time the moving slit takes to complete its run over the frame) ..... So. would this actually produce a more blurry effect than the same image and subject movement without any flash ...?
Should be easy enough to test with a fan and a HSS flash (I only have the former). No flash in the following links, but they do test the various rolling shutter effects (mechanical and electronic shutter) and get to play with lego at the same time: Micro 4/3rds Photography: Shutter readout speed.
10-16-2016, 07:30 AM   #18
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QuoteOriginally posted by mcgregni Quote
Ok. I see, sorry.... So in fact when in HSS mode it is the exposure time (eg 1/2000) that impacts on the motion freezing. Whereas longer times than the max sync it is the flash burst that has that impact .... You can get a double effect too, with flash frozen outlines and blurred effects around that. I think some people refer to this as ' dragging the shutter'.

I wonder though if with HSS the freezing effects are the same as without flash? Just thinking that even though the exposure is very short, there is a moving light passing over the whole frame ..... Regardless of the time value set this moving light (the HSS flash) takes 180th sec to pass over the whole frame (the time the moving slit takes to complete its run over the frame) ..... So. would this actually produce a more blurry effect than the same image and subject movement without any flash ...?
Even without a flash this is always true. So motion should be stopped as well as if no flash was used. The rolling shutter effect may be possible with the right speed and direction.
10-17-2016, 06:08 AM   #19
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QuoteOriginally posted by noblepa Quote
I'm not sure who actually makes this flash. I do know that Promaster is not a manufacturer. They buy products from other manufacturers and put their name on them, just as Vivitar does. It very well could be made by Tumax.

So far, I like it. The only significant feature is seems to be lacking is wireless flash control. I have seen nothing in the manual about that.

For the earlier poster who was not familiar with HSS, it is a technique that allows flash pictures to be taken with the shutter speed faster than the camera's "synch" speed. On a Pentax dslr, that speed is 1/180 second. That is the fastest speed at which the shutter is completely open. At faster speeds, the trailing curtain begins to close before the leading curtain has finished its run. This results in a moving slit across the image sensor.

An ordinary flash fires once (aside from the exposure-control pre-flash) at the instant the shutter is fully open. HSS mode allows the flash to fire multiple times, as the shutter traverses the image sensor. The cost is flash intensity. An HSS flash is not as bright as an ordinary flash.

It also has less motion-stopping power. An ordinary flash may have a duration as short as 1/50,000 second. I think it is 1/20,000 on my Promaster flash. That will stop a bullet in flight. In HSS mode, the motion stopping ability is that of the physical shutter, which on most cameras is 1/4,000 or 1/8,000 second.

Someone on a forum somewhere did an experiment to demonstrate this. He shot a tabletop fan (the kind used to provide a breeze in a hot room). with an ordinary flash exposure, the fan blades were perfectly frozen. In HSS mode, the fan blades were completely blurred.

HSS is particularly effective as a fill flash in bright sunlight, to compensate for shadows that may fall across the face of your subject. In bright sunlight, a shutter speed of 1/180, even with an aperture of f/16 or f/22, may still be enough to overexpose the picture. By raising the shutter speed, you can control the exposure caused by the ambient light, while using the flash to fill in the faces of your subject.
That was a fantastic explanation, thank you so much!

Daylight filling flash is exactly what I want, so now I'll start researching which HSS flash I'll get...

10-17-2016, 03:06 PM - 1 Like   #20
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QuoteOriginally posted by ChristianRock Quote
That was a fantastic explanation, thank you so much! Daylight filling flash is exactly what I want, so now I'll start researching which HSS flash I'll get...
If you haven't already seen it, this guide is excellent: Comprehensive Pentax P-TTL Flash Guide Updated - Articles and Tips | PentaxForums.com

And have a look at @McGregni 's practical guide to HSS here too, CR: A Practical Look at High Speed Synch
10-18-2016, 06:56 AM   #21
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So back to the Promaster FL160...

It is TTL so for Pentax DSLRs (other than the ancient ones like the the *istD) it's all manual settings, right?

Other than the AF540 and the upcoming Youngnuo YN585EX, are there any other P-TTL HSS options? It's hard to search Adorama or Amazon because their descriptions don't usually mention HSS. For the Promaster FL160, for example, it says "External flash for Pentax"... and the Amazon page doesn't even mention HSS or "high speed sync"...!

So, it's hard to research one to buy.
10-18-2016, 07:04 AM   #22
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Af360...
10-18-2016, 07:18 AM   #23
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QuoteOriginally posted by UncleVanya Quote
Af360...
Thanks... and there's the Metz 64 also, it seems? Adorama description just says "high speed", I guess that must mean high speed sync? Still, these are all still in the pricey side...

10-18-2016, 07:46 AM   #24
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Try this:

pttl.mattdm.org

At the moment it won't load but I'm hoping that is a temp glitch.
10-18-2016, 08:03 AM   #25
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QuoteOriginally posted by UncleVanya Quote
Try this:

pttl.mattdm.org

At the moment it won't load but I'm hoping that is a temp glitch.
Thank you good Sir, bookmarked
11-16-2016, 02:43 PM   #26
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QuoteOriginally posted by UncleVanya Quote
Af360...
So as an update... I didn't think I'd be able to afford this one - at least not the AF360fgz II which goes for at least 250 in the used market, usually - but I found one online in EX condition for 80 bucks And to my surprise, it actually showed up and was as advertised

I ran some HSS tests today with my F 50 1.7... got my first HSS shots, so I'm pretty happy. Next time I go out with the kids to a park during daytime, I'll get much better pictures
11-16-2016, 03:36 PM   #27
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QuoteOriginally posted by ChristianRock Quote
So as an update... I didn't think I'd be able to afford this one - at least not the AF360fgz II which goes for at least 250 in the used market, usually - but I found one online in EX condition for 80 bucks And to my surprise, it actually showed up and was as advertised

I ran some HSS tests today with my F 50 1.7... got my first HSS shots, so I'm pretty happy. Next time I go out with the kids to a park during daytime, I'll get much better pictures
That is a STEAL - great catch sir!
11-16-2016, 04:41 PM   #28
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Great get, CR. Enjoy it.
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