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06-17-2013, 05:54 AM   #16
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QuoteOriginally posted by Digitalis Quote
the shutter curtains will be visible at 1/250th and above.
Since there is no way to test that i'm very curious how you can be so sure... Canon and Nikon camera's are often able to go slightly past that limit.
If you do see a shutter you can take that into account and slightly crop the image.

The bad thing is that Pentax does not give us that option.
That it is disabled that way with the K30 okay, but with the K5 the user has to know that and judge if the risk is worth it or not.

06-17-2013, 06:00 AM   #17
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QuoteOriginally posted by thechumpen Quote
That's what I was thinking as well. Although pretty sure you need an external flash for that. At least my K-r does - there is no HSS option when using the inbuilt flash. However, if I use my Metz flash and set it to PTTL-HSS then I can get much faster shutter speeds (can't recall exact upper limit).
You want faster speed so that you have a lot of flash light and little daylight.
With HSS you easily have only 1/4th of the power you normally have.
So if you've 1/125 at full flash power you get the same balance roughly at 1/500 or 1/1000 shutter speed with HSS.

HSS simply isn't that useful, it's only really handy if you want to use the flash as fill light.
06-17-2013, 06:02 AM   #18
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QuoteOriginally posted by Anvh Quote
Since there is no way to test that i'm very curious how you can be so sure... Canon and Nikon camera's are often able to go slightly past that limit.
If you do see a shutter you can take that into account and slightly crop the image.

The bad thing is that Pentax does not give us that option.
That it is disabled that way with the K30 okay, but with the K5 the user has to know that and judge if the risk is worth it or not.
actually there is likely a way to use a CRT to evaluate the width of the shutter slit
06-17-2013, 06:12 AM   #19
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QuoteOriginally posted by thechumpen Quote
pretty sure you need an external flash for that.
Correctimundo.
The Sigma DG 530/610 Super series, the Pentax 360 and 540, various Metz - would all be necessary if you want to do HSS.

I know nothing about any of them - just read the details from here:
The Definitive Guide - Pentax P-TTL Flash Comparison

06-17-2013, 06:36 AM   #20
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QuoteOriginally posted by thechumpen Quote
That's what I was thinking as well. Although pretty sure you need an external flash for that. At least my K-r does - there is no HSS option when using the inbuilt flash. However, if I use my Metz flash and set it to PTTL-HSS then I can get much faster shutter speeds (can't recall exact upper limit).
Some other makes had flash sync at all speeds with f p shutters, to achieve this the flash had to fire several times per exposure. Back in 1966 I had a Zeiss Werra that had a leaf shutter up to 1/750 sec. As for sensor shake reduction, doe's anyone know how much it can move? Most professional roll film cameras with f p shutters had one or two leaf shutter lenses to get round the sync problems. The other older method was to use slow burning flash bulbs and F P sync which fired the flash just before the shutter opened. The flash bulb burned as the gap in the blinds traversed the film plane. The Z1P is a more advanced camera than the M Z S imo although nowhere near as good looking. I will be keeping the Z1P but the M Z S is bound for ebay soon.
06-17-2013, 06:43 AM   #21
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QuoteOriginally posted by pentasonic49 Quote
Some other makes had flash sync at all speeds with f p shutters, to achieve this the flash had to fire several times per exposure.
with pentax it is called high speed sync
QuoteQuote:
Back in 1966 I had a Zeiss Werra that had a leaf shutter up to 1/750 sec. As for sensor shake reduction, doe's anyone know how much it can move? Most professional roll film cameras with f p shutters had one or two leaf shutter lenses to get round the sync problems. The other older method was to use slow burning flash bulbs and F P sync which fired the flash just before the shutter opened. The flash bulb burned as the gap in the blinds traversed the film plane. The Z1P is a more advanced camera than the M Z S imo although nowhere near as good looking. I will be keeping the Z1P but the M Z S is bound for ebay soon.
the PZ-1 and PZ-1p are good cameras, but the whole issue of sync speed is not really that bad. we are discussing 1/2 stop difference. this is more a question of envy. if canikon only did 1/125 we would find simething else to complain about.

note that the sync speed also impacts shutter life,

the bigger issue is that we are much more limited with low ISO compared to film. a DSLR caps out at 100 or maybe 80, but we had 25 ISO film. so we give up a lot more stops with ISO and daylight balance, than we do with max sync speed
06-17-2013, 07:03 AM   #22
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QuoteOriginally posted by ksm Quote
well, in that case.... I have a good news and a bad news... The bad one is, the flash won't fire ...and the good one, your camera won't be fried!
..but I wish it worked that way as you said. sigh...
Well, that sucks. I thought maybe at least the hotshoe was still "hot" above 1/180.

This calls for desperate measures. Anybody have a IR-triggered flash or strobe that works with the same remote as the camera?
06-17-2013, 07:06 AM   #23
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QuoteOriginally posted by pentasonic49 Quote
Some other makes had flash sync at all speeds with f p shutters, to achieve this the flash had to fire several times per exposure. Back in 1966 I had a Zeiss Werra that had a leaf shutter up to 1/750 sec. As for sensor shake reduction, doe's anyone know how much it can move? Most professional roll film cameras with f p shutters had one or two leaf shutter lenses to get round the sync problems. The other older method was to use slow burning flash bulbs and F P sync which fired the flash just before the shutter opened. The flash bulb burned as the gap in the blinds traversed the film plane. The Z1P is a more advanced camera than the M Z S imo although nowhere near as good looking. I will be keeping the Z1P but the M Z S is bound for ebay soon.
I have just tried high speed sync with K5 and Metz 48 AF-1 shooting down the stairwell of my house at 1/8000 @ 2.8, increasing the ISO until at 3200 the exposure was acceptable. This is the great advantage of digital over film as with film I would not have known what the correct exposure was. By the way, without the flash the shutter speed needed to be 1/90 sec.

06-17-2013, 07:27 AM   #24
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QuoteOriginally posted by pentasonic49 Quote
I have just tried high speed sync with K5 and Metz 48 AF-1 shooting down the stairwell of my house at 1/8000 @ 2.8, increasing the ISO until at 3200 the exposure was acceptable. This is the great advantage of digital over film as with film I would not have known what the correct exposure was. By the way, without the flash the shutter speed needed to be 1/90 sec.
This certainly not the correct way to use it though.

The flash actually "strobe" in that mode so it does not freeze motion or anything.

You can probably get the same result in normal mode.
use ISO 400 up to 800 and the flash normally with shutterspeed at 1/180
Curious to see which one you like
06-17-2013, 07:28 AM   #25
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QuoteOriginally posted by Giklab Quote
Well, that sucks. I thought maybe at least the hotshoe was still "hot" above 1/180.

This calls for desperate measures. Anybody have a IR-triggered flash or strobe that works with the same remote as the camera?
Cactus v5
06-17-2013, 07:41 AM   #26
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QuoteOriginally posted by Anvh Quote
Since there is no way to test that i'm very curious how you can be so sure... Canon and Nikon camera's are often able to go slightly past that limit.
The reason for my certainty is because I know how shutter systems work. I work with Canon and Nikon cameras and I do notice a drop in the GN when full synch speed is being used, the difference between 1/180th and 1/250th is only really important when you are using focal lengths at or above 200mm.

QuoteOriginally posted by maxfield_photo Quote
But for the sake of argument, lets say that the black bars begin appearing at 1/181st of a second, that still doesn't mean that they will occupy the entire frame at first.
Correct, the black bars will not be immediately visible. It is interesting to note that in practically all modern shutter units the shutter blades are only moving at roughly 7m/s which is around 25.2 Km/h (15.6Mp/h). The T.1* time of the Pentax AF540FGZ at 1:1 power is said to be around T.1=1/400. So using this knowledge I'm sure someone could figure out how much of the frame would be black, as things stand the hour is too late for me to accomplish such a task at present. Burning the candle at both ends has its drawbacks.

*T.1 times are more relevant when one is trying to stop fast motion, The T.5 time for the AF540FGZ @ 1:1 power is approximately 1/1200th.
06-17-2013, 07:53 AM   #27
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This isn't what we are discussing.

You said that with Pentax you will see a black bar at 1/250, so far i've seen no proof of that.
06-17-2013, 08:01 AM   #28
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This is from the AF360 Operating Manual:
Flash duration (1/2 peak each) (M1/1) flash: Approx. 1/1200 sec. (TTL) Fastest duration time: Approx. 1/20000 sec.

The AF16 manual had a graph of flash intensity vs time (1/4000th to half) but I have never seen such a graph in the later flash manuals.
06-17-2013, 08:42 AM   #29
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QuoteOriginally posted by wombat2go Quote
This is from the AF360 Operating Manual:
Flash duration (1/2 peak each) (M1/1) flash: Approx. 1/1200 sec. (TTL) Fastest duration time: Approx. 1/20000 sec.

The AF16 manual had a graph of flash intensity vs time (1/4000th to half) but I have never seen such a graph in the later flash manuals.
When I tried out the high speed sync the strobing flash did not stop the motion but the 1/8000 sec shutter probably did. In this mode the flash power was greatly reduced and I can't think of many applications. Since my last post I have updated the firmware for the Metz (just because I could) after about half a dozen tries because there was no FTDI driver. Then by magic the driver appeared saying something about 64 bit Windows and everything worked. I would have used XP 32 bit if I had known.
06-17-2013, 08:43 AM   #30
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QuoteOriginally posted by Anvh Quote
You said that with Pentax you will see a black bar at 1/250, so far i've seen no proof of that.
Using a shutter speed of 1/250th when using flash as the sole light source with a shutter mechanism with a synch limit of 1/180th you Will see a black (unexposed) area. This isn't a question of proof, it is an inconvertible truth - if you had any idea how camera shutters work with flash you would know this.

HSS works my mimicking a continuous light source, something that a single-pulse flash doesn't do terribly well as it cannot be sustained for long, nor can it be used to illuminate large areas without boosting the ISO or by using a wider aperture.

Last edited by Digitalis; 06-17-2013 at 08:52 AM.
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