K7 and flash synchro-speed
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Posted 16/01/2010 - 15:54
Patrick the flash sync of the k7 is 1/180.
1/250 was mentioned was just a rumour going around.
With HSS (high shutter speed/sync) you can however sync past 1/180 but the flash need to support that since it's a special feature.
It come close to strobing the flash during the whole duration of the shutter movement.
SR can be left on, I never found it a problem with the K10D and never heard something about the other cameras. So it's safe to assume it's no problem with the K7 either.
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
1/250 was mentioned was just a rumour going around.
With HSS (high shutter speed/sync) you can however sync past 1/180 but the flash need to support that since it's a special feature.
It come close to strobing the flash during the whole duration of the shutter movement.
SR can be left on, I never found it a problem with the K10D and never heard something about the other cameras. So it's safe to assume it's no problem with the K7 either.
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Last Edited by Anvh on 16/01/2010 - 15:55
33 posts
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Posted 16/01/2010 - 16:02
ok - my fault, i wasn't clear. i know all of what you all said; about alpha 700, notwithstanding all above mentioned functionalities, it is said that if you disconnect SR, synchro speed goes from 1/200 to 1/250; so, i was wondering if same happened with K7 - am i clearer ?
Pentax - what else ?
Pentax - what else ?
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Posted 16/01/2010 - 16:08
Yes, you're but no SR doesn't have influence on flash sync.
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Link
Posted 16/01/2010 - 16:11
that's not what is written about alpha 700 - cf P. BUrian book ? - hence my question. ok, so end of post ? 
Pentax - what else ?
Pentax - what else ?
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Posted 16/01/2010 - 16:33
Flash sync is only influenced by the shutter cutains.
It could be that sony calibrated it very critical to get the higher sync numbers, probably they took the number on which they knew the curtains aren't infront of the sensor.
Because the SR move the sensor it needs to have a bit more room so a less critical number must be chosen.
I think Pentax took the less critical one and took the time the shutter is open fully, so no relative to sensor size or placement so SR does not influence the sync speed.
I'm not a photocamera engineer but it does make for a logical explanation.
ps. in my previous post I was talking about the K7 explicitly, sorry that I wasn't clear about that.
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
It could be that sony calibrated it very critical to get the higher sync numbers, probably they took the number on which they knew the curtains aren't infront of the sensor.
Because the SR move the sensor it needs to have a bit more room so a less critical number must be chosen.
I think Pentax took the less critical one and took the time the shutter is open fully, so no relative to sensor size or placement so SR does not influence the sync speed.
I'm not a photocamera engineer but it does make for a logical explanation.
ps. in my previous post I was talking about the K7 explicitly, sorry that I wasn't clear about that.
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Last Edited by Anvh on 16/01/2010 - 16:35
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Posted 16/01/2010 - 16:43
no problem - have a nice w/e !
Pentax - what else ?
Pentax - what else ?
Link
Posted 16/01/2010 - 16:46
You too Patrick 
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
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patrick
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Maisons Laffitte - France
Pentax - what else ?