[bdery]

Hi,

I wonder if your K-3 is behaving in this way... or in other words, I wonder what is the exact logic behind the implementation of HSS.

There appears to be no way to tell the camera that HSS will be used. I assume the camera expects to adapt itself to the flash, and if the flash wants to use HSS, the camera will let it.

When I set my flash to HSS PTTL (AF540 or Metz 52 AF1, they behave the same), nothing special happens on the camera.

In P mode, the camera will default to 1/180s. I cannot open the aperture to force it to use a faster shutter speed. I can, however, set a faster shutter speed and the camera will open the aperture... (annoying since I usually use P, and play with the aperture as needed)

In Av mode, I can set the aperture and the camera will adjust the shutterr speed accordingly.

In Tv mode, I can set the shutter speed as desired.

Since I basically live in P (or M) and prefer to set the aperture than the shutter speed, I find this a tad annoying, and illogical. I'm not even sure I'm doing things right. Any opinions?

[pearsaab]

Hi,

I wonder if your K-3 is behaving in this way... or in other words, I wonder what is the exact logic behind the implementation of HSS.

There appears to be no way to tell the camera that HSS will be used. I assume the camera expects to adapt itself to the flash, and if the flash wants to use HSS, the camera will let it.

When I set my flash to HSS PTTL (AF540 or Metz 52 AF1, they behave the same), nothing special happens on the camera.

In P mode, the camera will default to 1/180s. I cannot open the aperture to force it to use a faster shutter speed. I can, however, set a faster shutter speed and the camera will open the aperture... (annoying since I usually use P, and play with the aperture as needed)

In Av mode, I can set the aperture and the camera will adjust the shutterr speed accordingly.

In Tv mode, I can set the shutter speed as desired.

Since I basically live in P (or M) and prefer to set the aperture than the shutter speed, I find this a tad annoying, and illogical. I'm not even sure I'm doing things right. Any opinions?

i have a pentax 540 flash and the k3 camera and flash communicates...i always use tav mode so not sure if this makes any difference...when i set the flash to hss pttl the camera keeps the shutter speed where it is at...if i don't use hss the camera will set the shutter speed to 180...i guess i can try the other modes and see if it responds any differently

[stevebrot]

HSS is a flash feature, but is dependent on the P-TTL feature of the body. The body must be in a mode that supports P-TTL and there are limitations. I don't own either of your flashes, but on my Sigma EF-610 DG Super, HSS is enabled on the flash and the body must be in a mode that allows setting of the shutter speed. Behavior is as follows:

Edit:I did some more experimentation with HSS on the Sigma EF-610 DG Super and need to revise this list

• P mode (hyper-program) -- aperture defaults to maximum for lens. Range is limited based on that aperture and displayed as a scale on the flash LCD.
• Tv mode -- same as above
• Av mode --
• M mode -- Both aperture and shutter speed may be set, but flash range may be limited by selected aperture. On my flash there is a distance scale indicating max range for the selected aperture.
• TAv mode -- gross overexposure with my flash
• Bounce flash with HSS is unpredictable with my flash

New list

• The Sigma documentation defers to the camera manual for supported modes
• The K-3 manual indicates any mode that allows setting of the shutter speed (Tv is specifically suggested)
• All modes:
  • The combination of ISO above about 200 and dim light is problematic for the Sigma HSS implementation resulting in potential overexposure
  • Range is limited based on the taking aperture and ISO with the supported range being shown on the flash LCD display
  • Exposure using bounce flash and HSS is unpredictable (see preceding point regarding range)
• P mode (hyper-program) -- Yes, per program line. Note that this is a deviation from the Pentax AF540FGZ implementation where the documentation indicates a mode other than Programmed AE.
• Sv mode -- No, shutter always at 1/180s
• Tv mode -- Yes, aperture will follow program line with risk for decreased range (see above)
• Av mode -- Yes, per program line. Note risk for decreased range (see above)
• TAv mode -- Yes. Significant risk for overexposure per note above due to higher ISO (see above).
• M mode -- Yes
• X mode -- No, shutter always at 1/180s

I hope this helps. For what its worth, I am pretty sure my K10D was the same way.


Steve

[bdery]

HSS is enabled on the flash and the body must be in a mode that allows setting of the shutter speed. Behavior is as follows:
P mode (hyper-program) -- aperture defaults to maximum for lens. Range is limited based on that aperture and displayed as a scale on the flash LCD.

With my setup, n P mode even if the flash is in HSS PTTL, the camera defaults to around f20 in bright sunlight and will not let me open the aperture. It will let me increase the speed and open the aperture accordingly, however. In Av mode, I can set whatever apeture I want.

In short, based on your comment, I gather that HSS should be used with a Tv logic instead of an Av logic. I'll have to learn to do that

[stevebrot]

In short, based on your comment, I gather that HSS should be used with a Tv logic instead of an Av logic. I'll have to learn to do that

M mode is your friend.


Steve

[sinus007]

Bdery,
I almost always use Av mode when I switch my AF540 into HSS.
Sometimes it doesn't work, e.g. when I want shallow DOF and it's really bright the flash practically invisible because of high shutter speed.
Of course, as stevebrot mentioned, M is your friend, but in some cases isn't very practical.

[awaldram]

With my setup, n P mode even if the flash is in HSS PTTL, the camera defaults to around f20 in bright sunlight and will not let me open the aperture. It will let me increase the speed and open the aperture accordingly, however. In Av mode, I can set whatever apeture I want.

In short, based on your comment, I gather that HSS should be used with a Tv logic instead of an Av logic. I'll have to learn to do that

The camera will always attempt to use the flash as 'fill' irrelevant of hss providing your selected mode will allow it.

so to really control the flash balance you need to control the ambient exposure , there are many ways todo this from 'tv','X' to exposure comp but 'P' will not allow it at all so you will alays get 'fill' with 'P'

[bdery]

M mode is your friend.

Well, as much as I love using M for macro, studio, or some specific situations, when I want to use HSS is mostly when trying to photograph candids (often of kids) and M really doesn't cut it.

I experimented this weekend and Av mode works best for me with the workflow I'm most used to.

[stevebrot]

Well, as much as I love using M for macro, studio, or some specific situations, when I want to use HSS is mostly when trying to photograph candids (often of kids) and M really doesn't cut it.

I experimented this weekend and Av mode works best for me with the workflow I'm most used to.

I did some additional experimentation and revised my comments above. I also learned a little more about the Sigma HSS implementation and its limits (does not like higher ISO) and how it deviates from the Pentax implementation. I wonder if the Metz has similar quirks.


Steve

[awaldram]

I did some additional experimentation and revised my comments above. I also learned a little more about the Sigma HSS implementation and its limits (does not like higher ISO) and how it deviates from the Pentax implementation. I wonder if the Metz has similar quirks.


Steve

Hi iso shooting is a gotcha for all p-ttl/manual flahses it very easy to shoot @ a distance and ISO that reuires a flash burst shorter than the flash can deliver.

There is probably differences between manafacturer in just how quick they can shut off but all my cameras can out 'sensitivity' all my flashes from around iso 1600 up.

Generally when using flash the first thing I set is the ISO relative to the flash power I'll need normally be in the 100-400 range, Allowing 'auto' iso will generally get you into a world of pain with over flash power and fill instead of illuminated.

[stevebrot]

Hi iso shooting is a gotcha for all p-ttl/manual flahses it very easy to shoot @ a distance and ISO that reuires a flash burst shorter than the flash can deliver.

There is probably differences between manafacturer in just how quick they can shut off but all my cameras can out 'sensitivity' all my flashes from around iso 1600 up.

Generally when using flash the first thing I set is the ISO relative to the flash power I'll need normally be in the 100-400 range, Allowing 'auto' iso will generally get you into a world of pain with over flash power and fill instead of illuminated.

Thanks for chiming in here. This all makes perfect sense. I am a relative noob with P-TTL and generally shoot fixed low ISO, so it is with some degree of surprise when I actually started trying out the various modes and the corner-cases associated with each.


Steve