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01-23-2013, 06:52 AM   #31
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QuoteOriginally posted by mtb Quote
One more thing, which is sometimes forgotten when talking about max flash sync is the power (or maybe better to say efficency) of the flashgun. At maximum sync speed we have the most effective power from flashgun - more power, quicker recycle, etc. It is really good to have more than 1/180
I recommend you to visit THIS great article about the max flash sync.
Sync speed and flash power are independent. When using full flash it is the flash only that exposes the frame, and the ambient light is generally too low to give any illumination to the shot. Therefore since the flash is perhaps 1/500 in duration, it does not matter what the sync speed is the flash happens in much less time.changing the sync speed will not change the flash power used on a shot.

Now for fill flash, the inverse is true. Increasing sync speed reduces ambient light contributed for the exposure therefore to get the full exposure uses(again for fill flash) more flash power, not les

01-23-2013, 07:11 AM   #32
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For studio, the sync speed is not a problem but outdoors every little stop counts.
Half a stop doesnt sound much but it's the differnce between 600watt flash outdoors or a 900watt.

If this means no SR then so be it, with higherspeeds it isn't needed anyway.
01-23-2013, 10:47 AM   #33
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QuoteOriginally posted by Lowell Goudge Quote
Sync speed and flash power are independent. When using full flash it is the flash only that exposes the frame, and the ambient light is generally too low to give any illumination to the shot. Therefore since the flash is perhaps 1/500 in duration, it does not matter what the sync speed is the flash happens in much less time.changing the sync speed will not change the flash power used on a shot...
That's why he put the caveat in saying "(or maybe better to say efficency)". I think the article he linked explained it perfectly.
01-23-2013, 11:00 AM   #34
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QuoteOriginally posted by MPrince Quote
If you need a half-stop shutter speed more for your business requirements, why did you purchase Pentax gear? Pentax clearly doesn't fit your needs.
When I got back into photography a few years back, I did so, because I had a daughter showing an interest in photography and wanting a DSLR. I thought we could learn together, sharing a camera. My strict budget caused me to really look closely, and at that time, Pentax offered the most bang for the buck. I also had some Pentax accessories left over from my film days, so it made sense.

Had I known that I would become more and more serious about it, and which things I would grow into enjoying to photograph, then yes, Canon or Nikon would have been a better choice. If I continue going this direction, and Pentax does not improve certain things, then a switch would probably be the best route for me. At this point, I like Pentax and hope they advance things.

01-23-2013, 01:52 PM   #35
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QuoteOriginally posted by Lowell Goudge Quote
Sync speed and flash power are independent. When using full flash it is the flash only that exposes the frame, and the ambient light is generally too low to give any illumination to the shot. Therefore since the flash is perhaps 1/500 in duration, it does not matter what the sync speed is the flash happens in much less time.changing the sync speed will not change the flash power used on a shot.
This is not always true. Yes, when flash overpowers ambient, the shutter speed is irrelevant. Well, that really isn't always true either... but for argument sake to keep things in the realm of most normal use cases, it can be thought that way.

A faster shutter speed allows this to happen with less flash power. It also allows capture of fast moving subject when you cannot control the ambient light such as outdoors, or in a conference hall that won't turn off their lights -- just so that the photographer can can use his portable flash.
With infinite money to throw at super-powerful flash, and the help to carry it around and space to position it... all you need is some NDs to cut the light (ambient and flash).... and then maybe some sunglasses and high SPF sun lotion to keep your subject from getting burned.
01-24-2013, 03:36 AM   #36
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I guess I am not really understanding some of the statements made about Pentax synch speed in this thread, and particularly the one about Pentax doesn't "even allow a flash to be triggered at speeds faster than 1/180". This is a general statement that I am pretty sure isn't actually correct. However, there are some elements of the discussion reagarding relationship between shutter and flash power that are useful, and may become apparent in some circumstances that I am yet to personally discover.

Attached photo taken with K5, Sigma 500 f4.5 APO DG EX, Metz 58AF2 flash; Av mode, ISO 1000, f5.6, 1/2000th of a second (and the flash has been triggered just fine). In this case, HSS mode was the answer and I am just loving using the Metz in this mode.
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01-24-2013, 03:50 AM   #37
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QuoteOriginally posted by AdrianM Quote
I guess I am not really understanding some of the statements made about Pentax synch speed in this thread, and particularly the one about Pentax doesn't "even allow a flash to be triggered at speeds faster than 1/180".

Sorry, I should perhaps have been more specific.
Pentax allows flash above 1/180 only with a flash capable of handling Pentax's High Speed Sync. Due to the way it functions the flash power is reduced severely.

Without high speed sync (standard strobe), Pentax disables the pins that fire a flash when the shutter speed is above 1/180.
Most cameras allow flash to be fired at any shutter speed. This can result in the shutter closing prior to the flash firing completely and may result in a dark bar at one edge. But can also be timed with correct flash settings to allow decent photos to be taken at shutter speeds well beyond the normal max sync speed (I've heard of 1/1000s with what they are calling hyper-sync on cameras with normal sync speed of 1/200).

But since Pentax disables any chance of firing a normal strobe at that speed, we're stuck with 1/180.... or your can pretend you're Joe McNally with Joe McNally's budget and bring a half-dozen or more flashes that handle high speed sync to help overcome the sunlight.
http://www.strobist.blogspot.com/2008/05/joe-mcnally-desert-shoot.html
01-24-2013, 08:37 AM   #38
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QuoteOriginally posted by AdrianM Quote
I guess I am not really understanding some of the statements made about Pentax synch speed in this thread, and particularly the one about Pentax doesn't "even allow a flash to be triggered at speeds faster than 1/180". This is a general statement that I am pretty sure isn't actually correct.
It's 99% correct, my old film KX allows me to trigger the flash at any speed, but the max sync is 1/60. Any faster than that and I will start to get black bars in my shot from the curtains blocking the film. I'm sure most of the other manual focus film Pentax cameras allow this too. Now I have a PZ-1p, which is a very advanced film camera, and on it, the max sync speed is 1/250th, still slower than I'd like, but half a stop faster than 1/180th. It will not allow my to fire the flash at above-sync speeds.

But as for Pentax DSLRs, you cannot fire the flash in normal mode at speeds above max sync, period.Try it yourself, in Manual or Shutter priority, set your shutter speed to 1/250th, now engage the pop up flash. Notice anything? You shutter speed has dropped to 1/180th.

"I'll fix that," you say, "I'll use my PC socket as David Hobby suggests in this article: Strobist: Hacking Your Camera's Sync Speed, Pt. 2, so the camera won't know there's a flash attached." Well if you shot Nikon, you'd be on to something. The camera can't sense the presence of a flash on the hotshoe, and so it doesn't limit the shutter speed, nice huh? But the engineers at Pentax in their infinite wisdom sought to protect us from those nasty back bars at all costs, so if you perform the same test as above, but with the flash hooked to the PC socket, you'll notice that 1) your shutter speed won't be limited by the camera anymore, and 2) the flash still won't fire. There must be a command in the firmware that either limits the shutter speed, or disables all sync commands above max sync speed.

The same is true of an external speedlight on the hotshoe. It will limit the shutter speed if it detects a Pentax-dedicated flash on the shoe, but if you attach a non-dedicated flash, or say put electrical tape over the pTTL contacts leaving the center pin exposed, the camera will simply disable the sync commands, but the result will be the same - No flash above max sync.

The only way around it is to use a high speed sync capable flash on the hotshoe (or use another brand). The camera must check to see if there is a HSS flash, and if there is, it will allow you to increase your shutter speed. But, as soon as you cross into HSS territory, the maximum power of your flash drops by two stops (at least, and this is tested on a $400 top-of-the-line flash unit). Basically that means that if you would have been able to get the shot a 1/4 power at 1/180th, but you wanted the background a little darker, then HSS is a viable option. But if you were at half or full power in normal flash mode, say for a late afternoon portrait with the sun over your subject's shoulder, HSS will not save you, your subject will be too dark. Oh, and if you want to work with your speed light off camera, you have to have a second speedlight on the hotshoe, or HSS will not function for the reasons discussed above.

It's a flawed system, but not everyone uses those features, and so many may not know about the limitation. Outdoor portrait photographers know for sure. Sports photographers know. Probably most wedding photographers know if they've ever tried to shoot the bride outdoors or in front of a window with a speedlight. Those are really important segments of the professional market, and Pentax needs to realize that they are just bleeding away serious customers (or not picking them up in the first place). Pentax needs to increase the max sync speed, either by using more robust albeit slightly more expensive shutters, or by going to a leaf shutter system in their professional lenses. And they need to allow users to disable "black bar protection" via the custom function menu.

01-24-2013, 11:25 AM   #39
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Do we actually need HHS at all with very fast shutter speeds?

Flash duration at full power is about 1/500 right so with 1/4000 or 1/2000 you would capture the flash across the frame, not sure how the lights peak and all.
01-24-2013, 02:04 PM   #40
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QuoteOriginally posted by Anvh Quote
Do we actually need HHS at all with very fast shutter speeds?

Flash duration at full power is about 1/500 right so with 1/4000 or 1/2000 you would capture the flash across the frame, not sure how the lights peak and all.
Not if Pentax would allow you to fire the flash at shutter speed above 1/180. Other brands allow this and you can make use of long flash durations to cover the higher shutter speed.

Remember that although the shutter speed may say 1/1000, this is actually more correctly termed the exposure time. A small segment of the sensor is exposed for 1/1000 second as the first and second curtains create a small slit exposing only a portion of the sensor at any given moment. The entire time it takes to expose the entire sensor is still much slower than 1/1000 (I believe still about 1/180 due to mechanical limitations -- this is why propeller blades look curved when photographed with high "shutter speeds")... so your flash duration needs to be exceptionally long. HHS will repeatedly fire the flash rapidly over the course of the progression of the curtains trip across the sensor. A standard strobe would need to create one single flash with a significantly long decay to "consistently" light the entire duration of time it takes the first and second curtains take to sweep across the sensor.

PocketWizard has a mode termed Hypersync that apparently does this with some success... but again, only for cameras that allow flash to be fired above their sync speed. Sad, crippled Pentax DSLRs cannot do this.

Last edited by amoringello; 01-24-2013 at 02:16 PM.
01-24-2013, 04:33 PM   #41
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QuoteOriginally posted by Lowell Goudge Quote
I won't profess to being up on studio lighting etc. but that is not what I was looking at. I was simply looking at suggesting that the issue of maximum sync speed is best addressed by a leaf shutter in lens, not a focal plane shutter,
Sorry about the rant, but even with leaf shutters you still get, how shall I say, a slight vignetting towards the edges of the frame at high shutter speeds and flash durations. This is due to the, and we are talking very tiny amouts of time, shutter opening up, kind of like the aperture closing down for the shot, but in reverse.. Sorry I'm complicating things here, but I'm just saying that in my experience this happens.. I hope this helps, photography is all about compromise and work arounds, Pentax has some fantastic cameras which work great with my old lenses(Bonus!). I find that anyone with a Pentax usually has some knowledge about taking pictures and will find a work around method, which I like, it makes you think a little. Whereas your average CaNikon owner just uses theirs as an oversized point and shoot. I liken it to that scene in Ants where its the "Leaf" and they grind to a halt, a Pentax user would find a way round. Oh I seem to have gone on a bit, but hey, was only apologising about the rant.

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01-25-2013, 05:26 AM   #42
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QuoteOriginally posted by DayleT Quote
Sorry about the rant, but even with leaf shutters you still get, how shall I say, a slight vignetting towards the edges of the frame at high shutter speeds and flash durations. This is due to the, and we are talking very tiny amouts of time, shutter opening up, kind of like the aperture closing down for the shot, but in reverse.. Sorry I'm complicating things here, but I'm just saying that in my experience this happens.. I hope this helps, photography is all about compromise and work arounds, Pentax has some fantastic cameras which work great with my old lenses(Bonus!). I find that anyone with a Pentax usually has some knowledge about taking pictures and will find a work around method, which I like, it makes you think a little. Whereas your average CaNikon owner just uses theirs as an oversized point and shoot. I liken it to that scene in Ants where its the "Leaf" and they grind to a halt, a Pentax user would find a way round. Oh I seem to have gone on a bit, but hey, was only apologising about the rant.

Dayle
The whole problem here is we are arguing about a 1/3 stop difference which in almost all cases is meaningless between 1/180 and 1/250 sync speed. The real problem here is the same as the full frame argument. Since the others offer it, even though it may not be a benefit Tom most shooters, they see it as a weakness and argue it should be provided even if it will not be useful
01-25-2013, 05:43 AM   #43
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QuoteOriginally posted by Lowell Goudge Quote
The whole problem here is we are arguing about a 1/3 stop difference which in almost all cases is meaningless between 1/180 and 1/250 sync speed. The real problem here is the same as the full frame argument. Since the others offer it, even though it may not be a benefit Tom most shooters, they see it as a weakness and argue it should be provided even if it will not be useful
I agree with you, though I will say a faster max sync speed is useful to people who use flash outdoors and need to overpower the sun. But that small difference in max sync speed can be overcome using more powerful flashes combined with a good quality variable ND filter. Heck, you can turn day into night with a single speedlight and an ND filter. This image was taken in the middle of May on a bright, sunny afternoon at a little after 2 PM:




I shot this at 1/180, f8, with a Hoya ND8 neutral density filter.

Setup shot:



(Of course, in this example, it helps that the subject is small).
01-25-2013, 08:23 AM   #44
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QuoteOriginally posted by Lowell Goudge Quote
The whole problem here is we are arguing about a 1/3 stop difference which in almost all cases is meaningless between 1/180 and 1/250 sync speed. The real problem here is the same as the full frame argument. Since the others offer it, even though it may not be a benefit Tom most shooters, they see it as a weakness and argue it should be provided even if it will not be useful
I could not disagree more. (respectfully of course). I think the exact opposite phenomenon is at work, what I'll call the "good enough for me" mentality. If a feature is of no use to an individual for the work that they do, it's for easy for them to think of it as frivolous and unnecessary.

I'll give you an example of which I know I am guilty: auto white balance. I hate AWB and never use it, I'll shoot the entire afternoon with the wrong white balance, just as long as it's consistent, then I'll fix one shot in post, and apply it to the rest. That's just my workflow, it's geared towards fast production. For me AWB is a nuisance, and I would rather Pentax spend their R&D Yen on something that's more useful to me like flash. But to a novice shooter who probably works in JPEG and has enough on their plate just deciding what aperture to use in Av mode, AWB can mean the difference between a great vacation memory or an off color one.

It's the same with flash. If you're a studio shooter for instance, you don't have to deal with a lot of ambient light, and even the concept of shutter speed is a novelty, it's flash duration that counts. If you work outside, but always put the sun behind you, your biggest worry is probably raccoon eyes and how to fill them. If you're a "natural light shooter", flash itself is an unnecessary concept. But, if you like the look of contra-jour light in your photos, I can assure you that a high sync speed is of the utmost importance. It can mean the difference between carrying one or two inexpensive speed lights, and carrying thirty pounds of monolights, soft boxes, stands, and power inverters to a remote location. Just because it's "good enough for me", doesn't mean it's good enough for everyone.

By the way 1/180th to 1/250th is half a stop.
01-25-2013, 12:13 PM   #45
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QuoteOriginally posted by Lowell Goudge Quote
The whole problem here is we are arguing about a 1/3 stop difference which in almost all cases is meaningless between 1/180 and 1/250 sync speed. The real problem here is the same as the full frame argument. Since the others offer it, even though it may not be a benefit Tom most shooters, they see it as a weakness and argue it should be provided even if it will not be useful
Wow, imagine if we used this argument for all camera features! Maybe I could start the "average joe" camera company only concentrating on features that MOST people thought were useful. My system would have a max fps of 3, no grip available, not allow for a remote trigger, max ISO of 1000, etc... etc... etc... And the AverageJoeForums website would have nobody requesting new features, or debating features needed. Sounds like a fun place.

I agree with you that this max synch speed is not an issue for MOST photographers. For some it is, and that's why we are having this discussion.

I think the two areas where Pentax falls short that allows users of other systems to scoff at Pentax are the flash system, and the autofocus system. If Pentax could close the gap in these two areas, they could at least be in consideration for more photographers. The more people buying, the more money for R&D for all parts of the system, some of which will be the area that happens to be important to each user.
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