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09-28-2010, 05:11 AM   #1
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K-5: Any word on cheating the flash sync speed?

I haven't seen anything other than the 1/180 sync speed spec, so I was hoping to see if anyone at Photokina had tested or asked about speeds faster than that (unofficially).

That is, on other cameras, either the hotshoe x-contact or pc sync port is still activated at faster than x-sync speeds, allowing you to cheat the official sync speed. For example, at 1/300 you might still be able to get 3/4 of the entire frame synced with flash, allowing you to crop in. This wouldn't be that bad a compromise with the higher resolution now. On all the recent Pentax models, I have noticed that the flash contacts are de-activated once you are faster than 1/180.

This was one of the hopes that I had with the firmware hack projects that were being developed (e.g. focus adjustments). Any more word on this from anyone?

Thanks!

P.S. Please refrain from the constant questions about why this might be necessary or "just use HSS." It's not just for higher shutter speeds for action. A higher sync speed allows for easier balanced daylight with flash shots, for example, without having to resort to HSS which drastically reduces effective flash power (e.g. working distance and/or aperture flexibility). If you don't understand why this may be relevant/desired, check out strobist type sites for examples.


Last edited by thigmo; 09-28-2010 at 05:15 AM. Reason: Added P.S.
09-28-2010, 05:14 AM   #2
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You'd think but for some reason Pentax won't allow any sort of flash sync after 1/180. It's something so simple that could be changed in the firmware.

Apparently Pentax's own flashes are unable to properly sync faster than 1/180 so it's disabled.

As to any more answers, only Pentax's knows.....
09-28-2010, 05:15 AM   #3
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I wouldn't count on that, unfortunately.
09-28-2010, 05:26 AM   #4
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At least we get ISO 80 which makes daylight fill flash somewhat easier, though I wish the camera went as low as ISO 50, or 25.

09-28-2010, 05:28 AM   #5
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QuoteOriginally posted by Digitalis Quote
At least we get ISO 80 which makes daylight fill flash somewhat easier, though I wish the camera went as low as ISO 50, or 25.
True, well how does going down to 80 affect IQ?



What I've wondered is, is there any way to trick the camera in thinking a P-TTL flash is connected in HSS mode, then again that'd require some fancy circuity and knowing the protocols....too much effort lol.

Then again there is always ND filters
09-28-2010, 05:54 AM   #6
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QuoteOriginally posted by Christopher M.W.T Quote
True, well how does going down to 80 affect IQ? What I've wondered is, is there any way to trick the camera in thinking a P-TTL flash is connected in HSS mode, then again that'd require some fancy circuity and knowing the protocols....too much effort lol. Then again there is always ND filters
i'm uncertain on how the K5 performs at ISO 80 Falk and others on this site should be able to answer such a question but I suspect it will perform very well.

as far as I know there is not way to "trick" the camera into thinking there is a HSS enabled flash on the camera. the only practical way of circumventing the 1/180th synch speed "limitation" is by using a 645 or 67 series leaf shutter lens that can sync all the way up to 1/500th

ND filters are a pain in the arse, they make your viewfinder dark. When I really need to underexpose ambient light, I usually put on a linear polariser on my 50mm f/1.2 then I can darken the sky as well as push the ambient exposure under a stop or two, and still achieve shallow DOF.
09-28-2010, 06:36 AM   #7
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QuoteOriginally posted by Digitalis Quote
i'm uncertain on how the K5 performs at ISO 80 Falk and others on this site should be able to answer such a question but I suspect it will perform very well.

as far as I know there is not way to "trick" the camera into thinking there is a HSS enabled flash on the camera. the only practical way of circumventing the 1/180th synch speed "limitation" is by using a 645 or 67 series leaf shutter lens that can sync all the way up to 1/500th

ND filters are a pain in the arse, they make your viewfinder dark. When I really need to underexpose ambient light, I usually put on a linear polariser on my 50mm f/1.2 then I can darken the sky as well as push the ambient exposure under a stop or two, and still achieve shallow DOF.
Where'd you find a 50mm 1.2 in Australia? and how much?

Leaf shutter lenses hey? they are they compatible with a standard Pentax DSLR?
09-28-2010, 06:48 AM   #8
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QuoteOriginally posted by thigmo Quote
I haven't seen anything other than the 1/180 sync speed spec, so I was hoping to see if anyone at Photokina had tested or asked about speeds faster than that (unofficially).

That is, on other cameras, either the hotshoe x-contact or pc sync port is still activated at faster than x-sync speeds, allowing you to cheat the official sync speed. For example, at 1/300 you might still be able to get 3/4 of the entire frame synced with flash, allowing you to crop in. This wouldn't be that bad a compromise with the higher resolution now. On all the recent Pentax models, I have noticed that the flash contacts are de-activated once you are faster than 1/180.

This was one of the hopes that I had with the firmware hack projects that were being developed (e.g. focus adjustments). Any more word on this from anyone?

Thanks!

P.S. Please refrain from the constant questions about why this might be necessary or "just use HSS." It's not just for higher shutter speeds for action. A higher sync speed allows for easier balanced daylight with flash shots, for example, without having to resort to HSS which drastically reduces effective flash power (e.g. working distance and/or aperture flexibility). If you don't understand why this may be relevant/desired, check out strobist type sites for examples.
Thanks for bringing this up. I have been wondering about this issue my self. Delivering a simple sync shortening at all shutterspeeds would be really helpfull for all who wants to experiment. It would also be good for triggering remote cameras.

09-28-2010, 06:54 AM   #9
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QuoteOriginally posted by Christopher M.W.T Quote
Where'd you find a 50mm 1.2 in Australia? and how much?

Leaf shutter lenses hey? they are they compatible with a standard Pentax DSLR?
With 645->K adapter they are but of course without any automatism. In this context you probably don't care a lot (==> stop down metering).
09-28-2010, 06:55 AM   #10
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QuoteOriginally posted by Christopher M.W.T Quote
here'd you find a 50mm 1.2 in Australia? and how much?
I collect 50mm lenses for 35mm cameras and out of a selection of 178 of them(at last count) the SMCP-K 50mm f/1.2 is my favourite. I actually was given mine at age 15 by my mum who has an affinity for using the fastest lenses she can get her hands on ( she pinches my leica noctilux 50mm f/1.0) so I don't know how much it cost.

QuoteOriginally posted by Christopher M.W.T Quote
Leaf shutter lenses hey? they are they compatible with a standard Pentax DSLR?
yes but they have to be used in conjunction with the 645 to 35mm K mount adapter or the 67 to K mount adapter, you need to set your DLSR camera's shutter to a slower speed than what you are synching at - I would recommend about 1/60th to be on the safe side. Because of the adapters you are going to be working with no metering,or automation. But leaf shutter lenses are the only practical way to get past the 1/180th synch speed on pentax DSLR's.

For 645 format there is a 75mm f/2.8LS and 135mm f/4LS - the LS of course stands for Leaf Shutter, and they both offer 1/500th synch speeds. They have a PC synch plug on the lens itself so that professional strobes can be used, however you can use a hot shoe adapter in order to use the leaf shutter lens with a camera mounted strobe if that is desired.
09-28-2010, 07:52 AM   #11
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QuoteOriginally posted by Christopher M.W.T Quote
You'd think but for some reason Pentax won't allow any sort of flash sync after 1/180. It's something so simple that could be changed in the firmware.

Apparently Pentax's own flashes are unable to properly sync faster than 1/180 so it's disabled.

As to any more answers, only Pentax's knows.....

This is only somewhat true. The flash could sync at as high a speed as you want, but the flash burn time is long enough at full output that a higher sync speed clips some of the flash output.
There are two ways to get a high amount of light out of a flash. One is a high output flash system with a short burn time, the other is a lower output system with a longer burn time.
I suspect Pentax went the former route because of cost issues (IE: too many users would whine about the cost of a flash with the necessarily beefed up components to allow a higher sync speed).
09-28-2010, 08:01 AM   #12
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I don't know what you guys are talking about!

I own an AF-360FGZ and use it with my K-7. I swear I can get it to sync every time at 1/320 and I have even used to sync at 1/800. All of the shots were on the P-TTL mode.

My next flash will probably be the AF-560 with a beamer and I figure it will be powerful enough for me to notice a differnce beyond 1/1000 of a second.

Oh, and I believe you also need to have your flash on the HS setting in order to accomplish these higher speeds.

Last edited by traderdrew; 09-28-2010 at 08:13 AM. Reason: forgot to mention
09-28-2010, 08:25 AM   #13
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QuoteQuote:
What I've wondered is, is there any way to trick the camera in thinking a P-TTL flash is connected in HSS mode, then again that'd require some fancy circuity and knowing the protocols....too much effort lol.
Radiopoppers (I think the first gen) were able to do this wirelessly (they "listen" for and convert the hss signals to a radio signal and then convert back at the receiver) so you can move the flash closer, somewhat negating the loss in power. Unsupported officially though. However, like you said, likely too much effort to do it natively.


QuoteQuote:
Then again there is always ND filters
Not only are they (polarizers too) a pain when you're actually shooting on the fly, you're still losing flash power even more so then.

QuoteQuote:
Leaf shutter lenses hey? they are they compatible with a standard Pentax DSLR?
Leaf shutters lenses (645 versions are the 75 and 135) but with the adapter it would be fairly clumsy. I haven't tried this but I don't think I'd have the patience to do this on a shoot. The adapter is dumb (i.e. no coupling) so you would have to stop down meter (not a big deal I guess, you could take a couple test shots first), but again you'd have a darker viewfinder as well as needing a pc-sync cable (you know how reliable those are) connected from camera to lens, as well as ensuring your body shutter speed is slower than the lens'. I've also wondered if the sync would be reliable; there must be some mechanical delay between camera shutter press and the lens' shutter actuation, so you'd have to experiment (e.g. maybe need to use 1/60 on the body, like on the 645).

The other issue too is that the 75 and 135 focal lengths are really long for normal use. The 75 might work for tighter portraits, but it would be nice to have a wide.
09-28-2010, 08:25 AM   #14
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QuoteOriginally posted by Digitalis Quote
I collect 50mm lenses for 35mm cameras and out of a selection of 178 of them(at last count) the SMCP-K 50mm f/1.2 is my favourite. I actually was given mine at age 15 by my mum who has an affinity for using the fastest lenses she can get her hands on ( she pinches my leica noctilux 50mm f/1.0) so I don't know how much it cost.



yes but they have to be used in conjunction with the 645 to 35mm K mount adapter or the 67 to K mount adapter, you need to set your DLSR camera's shutter to a slower speed than what you are synching at - I would recommend about 1/60th to be on the safe side. Because of the adapters you are going to be working with no metering,or automation. But leaf shutter lenses are the only practical way to get past the 1/180th synch speed on pentax DSLR's.

For 645 format there is a 75mm f/2.8LS and 135mm f/4LS - the LS of course stands for Leaf Shutter, and they both offer 1/500th synch speeds. They have a PC synch plug on the lens itself so that professional strobes can be used, however you can use a hot shoe adapter in order to use the leaf shutter lens with a camera mounted strobe if that is desired.
I'd love to see one of your pics taken with this Summicron F1.0!

JP
09-28-2010, 08:26 AM   #15
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QuoteOriginally posted by traderdrew Quote
I don't know what you guys are talking about!

I own an AF-360FGZ and use it with my K-7. I swear I can get it to sync every time at 1/320 and I have even used to sync at 1/800. All of the shots were on the P-TTL mode.

My next flash will probably be the AF-560 with a beamer and I figure it will be powerful enough for me to notice a differnce beyond 1/1000 of a second.

Oh, and I believe you also need to have your flash on the HS setting in order to accomplish these higher speeds.
Samples with EXIF intact? This I have to see. The point I was trying to make that I DON'T want to have to use HSS.
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