[*isteve]

So am I reading the chart wrong where HSS is concerned? TAv mode, Camera - trailing sync, Flash - HSS, Sync - L, seems to say you get Leading Curtain instead of HSS to me.

Thank you
Russell

HSS is not available in TAv or Sv mode, at least on the K20. Assume its the same on the K7

Updated set of tables and some tips here. PLease not its a bit more complicated than the first table indicated. For "auto" read "auto or normal"

Flash Modes for Pentax Photo Gallery by Steve Jacob at pbase.com

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Last edited by *isteve; 12-16-2009 at 07:21 PM.

[maconmatt]

whew, thanks! Yeah, this is going to take some time to figure out.

[Canada_Rockies]

So am I reading the chart wrong where HSS is concerned? TAv mode, Camera - trailing sync, Flash - HSS, Sync - L, seems to say you get Leading Curtain instead of HSS to me.

Thank you
Russell

HSS will always use Leading curtain mode. If you think about what the flash has to do, it becomes obvious, as it always is after you have figured something out.

High Speed Sync flashes multiple times as the shutter slit passes over the sensor/film to defeat the fact that part of the sensor/film is covered by the flash at all times above the X shutter speed. It must switch the flash to Leading Curtain sync with HSS.

[jpzk]

It is a really complicated question. What works or doesn't work is partly controlled by what mode you are shooting in.



This was put together by isteve at dpreview.

Attachment 49518

Thank you
Russell

Hi Russell.
I copied this chart for easy reference and I would like to ask a couple of questions:
1. Is this chart to be used with P-TTL?
2. Strictly for fill-in, (either inside for portrait or outside with a backlit subject) would this work:
- Camera in Av mode, using a wide aperture to try and blur the background.
- Flash set to HSS
- P-TTL
- Use the flash compensation dial for balancing the scene.
- Lens used: DA*16-50
I wonder if that would work also, if it does, with a FA50/1.4 and a Zeiss 85/1.4.

Cheers.

JP

[Russell-Evans]

These questions are actually really pushing the limits of my knowledge, so hopefully someone else will provide better answers to them. I will answer with what I think, but do not know.

1. Is this chart to be used with P-TTL?

I think the chart is only valid for P-TTL. You might also want to look at the link Steve provided to his updated version of this. I'm still digesting the information in it.

2. Strictly for fill-in, (either inside for portrait or outside with a backlit subject) would this work:
- Camera in Av mode, using a wide aperture to try and blur the background.
- Flash set to HSS
- P-TTL
- Use the flash compensation dial for balancing the scene.
- Lens used: DA*16-50
I wonder if that would work also, if it does, with a FA50/1.4 and a Zeiss 85/1.4.

I mostly just use flash with the camera's M mode, so I don't really have much experience with the other camera modes. My thought would be that Av doesn't give you control over the shutter speed, so the scenario you described would be pretty scene dependent. HSS also drops the flash output drastically, so you probably would have to experiment to even understand the environments where HSS would actually be a workable solution.

Thank you
Russell

[egordon99]

2. Strictly for fill-in, (either inside for portrait or outside with a backlit subject) would this work:
- Camera in Av mode, using a wide aperture to try and blur the background.
- Flash set to HSS
- P-TTL
- Use the flash compensation dial for balancing the scene.
- Lens used: DA*16-50
I wonder if that would work also, if it does, with a FA50/1.4 and a Zeiss 85/1.4.

Cheers.

JP

Hi! That should work for fill-in flash, except indoors because Av mode will set a SLOW shutter speed (based on the ambient) so you might either need to use -2EC or just go into manual mode. Outside should be fine as the ambient light is usually more than enough to give you a fast shutter speed. In addition to using FEC for the "flash" exposure (how much fill do you want?), EC will adjust the ambient (background) exposure.

I know it will work with the FA, not sure about the Zeiss, but if it transmits the aperture to the camera (is there an "A" setting on the aperture ring?), then you should be good to go

[jpzk]

These questions are actually really pushing the limits of my knowledge, so hopefully someone else will provide better answers to them. I will answer with what I think, but do not know.



I think the chart is only valid for P-TTL. You might also want to look at the link Steve provided to his updated version of this. I'm still digesting the information in it.



I mostly just use flash with the camera's M mode, so I don't really have much experience with the other camera modes. My thought would be that Av doesn't give you control over the shutter speed, so the scenario you described would be pretty scene dependent. HSS also drops the flash output drastically, so you probably would have to experiment to even understand the environments where HSS would actually be a workable solution.

Thank you
Russell

Hi Russell,
If you are talking about the slide "show" which goes on for about 8 pages, I did downloaded and printed that too. It is truly overwhelming though.

For the fill-in, I will check other things then. Experimenting is the key I suppose.

Thanks,
JP

[jpzk]

Hi! That should work for fill-in flash, except indoors because Av mode will set a SLOW shutter speed (based on the ambient) so you might either need to use -2EC or just go into manual mode. Outside should be fine as the ambient light is usually more than enough to give you a fast shutter speed. In addition to using FEC for the "flash" exposure (how much fill do you want?), EC will adjust the ambient (background) exposure.

I know it will work with the FA, not sure about the Zeiss, but if it transmits the aperture to the camera (is there an "A" setting on the aperture ring?), then you should be good to go

Thanks for the reply.

So, inside I am better off using the M mode ... both on camera and flash? And do some experimenting with that. People are usually not too fond of being flashed at dozens of times though; I'll need to practice on static objects ... safer!
Outside, I see that I can use Av.
Hmmm .... might as well get used to the manual mode(s) then.
How much fill-in do I need: just enough so that the subjects are well lit, without over-exp./under-exp. Don't we all want this perfectly exposed shot?
Yes, the Zeiss has the "A" setting and can be used much the same as the FA, so that means it should be quite alright to test that too.

Cheers.

JP

[egordon99]

Thanks for the reply.

So, inside I am better off using the M mode ... both on camera and flash? And do some experimenting with that. People are usually not too fond of being flashed at dozens of times though; I'll need to practice on static objects ... safer!
Outside, I see that I can use Av.
Hmmm .... might as well get used to the manual mode(s) then.
How much fill-in do I need: just enough so that the subjects are well lit, without over-exp./under-exp. Don't we all want this perfectly exposed shot?
Yes, the Zeiss has the "A" setting and can be used much the same as the FA, so that means it should be quite alright to test that too.

Cheers.

JP

You can still use P-TTL on the flash when the camera is in manual mode. Except when I'm working with the flash OFF CAMERA (usually into an umbrella and the subject is staying a constant distance from the light source), I use E-TTL (I'm a Canon shooter, but I used to shoot Pentax, and I like this forum )

Manual flash power requires one to adjust the flash power whenvever the light-source->subject distance changes. When the flash is on camera, this changes (almost) ALL THE TIME. So P-TTL tends to work better. When you're off camera, the light is on a stand and most stands don't walk around too much, so the power can remain constant, even if you move the camera around quite a bit.

[Russell-Evans]

You can still use P-TTL on the flash when the camera is in manual mode.

HSS is also only a P-TTL option, if we are still talking about HSS.

Manual flash power requires one to adjust the flash power whenever the light-source->subject distance changes. When the flash is on camera, this changes (almost) ALL THE TIME. So P-TTL tends to work better. When you're off camera, the light is on a stand and most stands don't walk around too much, so the power can remain constant, even if you move the camera around quite a bit.

Once you start bouncing the light, or mimic bare bulb, things can change in favor of manual flash, in my opinion. Effective maximum range of P-TTL metering varies according to focal length and aperture, but not ISO, the range is 15 feet at f5.6, 21 feet a f4 with the 360FGZ at 35mm for example. The light path from the flash to a ceiling, from the ceiling to the subject, and then from the subject to the lens, ends up a bit of distance. Get around bouncing off the ceiling by using a bounce card on the flash, and I have no idea what the range would be. Maybe 10 feet at f5.6 and 35mm would be a safe guide line? Put a bare bulb modifier on the flash that drops the output by at least a stop or two and the PTTL maximum range has got to get short.

Thank you
Russell