A Practical Look at High Speed Synch


McGregNi

Link Posted 28/04/2015 - 21:10
MattMatic wrote:
Nice practical examples

It is interesting that the flash in P-TTL mode is automatic even if the camera exposure mode is M. It is a nice way of controlling things. Matt

This aspect of independence with the P-TTL flash exposure measuring from the camera exposure mode seems to take on extra significance with older lenses ..... non auto-focus non-coupled lenses are not compatible with P-TTL as the system needs the aperture information from the lens and distance from the focus system. However the measuring of light output during HSS operation is clearly different as it is monitoring what is effectively a continuous light source and powering that through a fast moving 'slit' of the shutter blades.

The result I have found is that HSS measured P-TTL exposures are perfectly good and consistent with manual focus A series coupled & older non-coupled lenses, which is a great bonus for us Pentaxians !!

Here are a few more recent examples continuing the family theme, this time in the garden. Here I was using an SMC A50mm f1.7 .... it was a bright sunny afternoon, very bright conditions, but I wanted to take advantage of the great depth of field effect available with this lens, so I set f2.0. But this resulted in shutter speeds way beyond the max sync speed of 180thsec .....

So, in manual exposure mode I set a shutter time value suitable for the bright light with a little underexposure for balancing .... around 1/3200 - 1/4000sec. This left my subjects faces in shadow and too dark, so the AF540-FGZ was mounted on the hotshoe, directly facing the subjects, and HSS mode set with -0.5 flash compensation set ....





















The results give a balance between the foreground subject light and the background while allowing me to those lovely DOF effects. HSS to the rescue again !!
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Last Edited by McGregNi on 28/04/2015 - 21:12

McGregNi

Link Posted 15/11/2015 - 20:18
I want to show a couple more examples taken more recently, which seem to show good common lighting conditions for HSS fill-in light balancing control.

Both these portraits have similar strong sunlight from the right side, which is nice natural lighting giving good depth and contrast on the surrounds. But of course it is glaring bright, and the faces are in shadow without any flash. It is not an option to expose for the faces, as this would produce overexposure behind, and I wanted the deeper tones and quality colours that a small underexposure of ambient light brings.

Of course, with fairly wide apertures for portraits that sends me straight away to very short exposure times .... 1/640th and 1/800th sec. So I need HSS flash to light the faces, and bring the needed contrast control. The side lighting, particularly in the first one, adds greater complexity to the appearance of the lighting, suggesting perhaps rather more to the flash set-up than a single bare direct Pentax AF-540FGZ .....









My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

richandfleur

Link Posted 15/11/2015 - 20:37
Good examples there Nigel.

McGregNi

Link Posted 15/11/2015 - 22:17
Thanks Richard .... I should have said that the equipment used for those two shots was the Pentax K7 DSLR, Pentax SMC F35-70mm 1:3.5-4.5 lens, and the Pentax AF-540FGZ flash for the first and AF-540FGZII for the second.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

smile_j

Link Posted 24/10/2017 - 12:00
Great photos and really good advice, it`s definitely useful! Thank you for sharing!

RobL

Link Posted 26/11/2017 - 16:31
I have a question: does HSS only work when exposing for ambient light? The reason I ask is I just tried a very underexposed setting indoors, with 1/250 sec in HSS; result, no flash apparent in the image although it did fire so the same as if there was no flash. Same thing at 1/200 (sync speed for K1) and the flash illuminated correctly.

McGregNi

Link Posted 26/11/2017 - 19:11
Hi Rob, the basic answer is no .... There does not need to be any visible ambient light in an exposure in order for HSS flash to work ..... You should be able to see the flash-lit parts of the scene even if the rest is totally black.

Generally when the light is dim then there's no purpose for HSS flash. It comes into it's own when needing to create a balance between bright ambient light and a flash-lit subject.

From what you described it sounds as if either the flash did not sync correctly for some reason when you shot at 1/250th, or there was insufficient power for it to be seen (eg it hadn't recycled enough).The first problem seems the most likely since you didn't get any flash light recorded.

What equipment are you using, the mode settings etc ... ?
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

RobL

Link Posted 26/11/2017 - 20:05
Hi McGregNi, I was just messing about with the K1 + 24-70mm at different focal lengths and an AF360 FGZII flash hot shoe mounted, set to HS, manual setting at different speeds between /1000 to 1/250 and f2.8 iso100. I could see the flash fire but there must have been a mismatch between the shutter and flash because it came out dark. Winding the speed up to 1/200, when the flash reverted to TTL, and it was fine. The manual says I should see the useable distance on the flash screen but there was nothing.

RobL

Link Posted 26/11/2017 - 21:09
Problem solved! Cleaned the contacts and now perfect exposures down to 1/8000 sec! Amazing.

McGregNi

Link Posted 27/11/2017 - 17:53
That's good, glad its sorted!
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

DSP121

Link Posted 15/03/2018 - 04:17
Little girl totally looks like a star!
Great pictures, will definitely try out the technique!
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richandfleur

Link Posted 15/03/2018 - 19:41
Cool post Nigel!

Quite motivating as well as informative and with great practical examples. Thank you 🙂👍🏻

retsoor

Link Posted 06/09/2018 - 20:11
Really interesting with great photos

McGregNi

Link Posted 07/09/2018 - 12:34
Thanks for those last comments, and I really hope the thread has encouraged you to look for opportunities out and about for some HSS light balancing and control!
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

Darkmunk

Link Posted 23/12/2018 - 15:44
Hi Nigel, been away for a while.
Nay idea what the state of play is with remote HSS now (Dec 201.
I still can't find anything out there. I can't believe Pentax hasn't come up with a radio trigger. I need it almost every time I shoot an event, but just have to make do with on-camera flash or reflectors and an assistant
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