K7 Shutter speed with flash in Av

dnmtsn` · 05-14-2010, 04:51 AM

Hi. I tried to find an answer using the search but nothing came up.

I am using my K7 with a Metz 48 flash in Av, with the Metz installed on the camera.
My problem is that in this setup the K7 always sets the shutter speed at 1/60. I have no idea why that happens as maximum flash sync speed is faster than that.

Is there a way to have it set the shutter speed to the maximum 1/180 in this setup? I know I can get that using M but I would like to have it in Av.

Thanks,
Dan

rockmaster1964 · 05-14-2010, 05:19 AM

In Av the camera will set the shutter speed based on the focal length of the lens. If you want it at 1/180 all the time put the camera in X and then set your aperture.

**Lowell Goudge** · 05-14-2010, 06:10 AM

As noted by rockmaster1964 the pentax cameras will, if the lens is an AF lens, set shutter speed to match focal length when in AV mode.

If you enable auto ISO it will attempt to make the exposure you need with natural light first, then add flash accordinglyu so you are not really in control.

What I do is set in manual mode when I want control, and then make my settings watching the light meter to see how much I want to have natural light and how much I want the flash to contribute

dnmtsn` · 05-20-2010, 03:17 AM

this is revealing, thanks a lot. I had no idea about the connection between focal length and shutter speed in Av. Is this documented in the user manual, or is it general knowledge?
Indeed, if I use a 50mm lens, the speed is set at 1/90; it's 1/60 with a 35mm.
I will try to do what you suggested.

RBellavance · 05-20-2010, 05:42 AM

In Av, you "give up" control of the shutter speed (just like you "give up" control of the aperture in Tv). If you need a specific shutter speed, you have three choices:

- M (complete control, and what I normally use with a flash)
- TAv (like M but with Auto ISO)
- X (shutter fixed 1/180s)
- Tv (but you give up control of the aperture)

dnmtsn` · 05-20-2010, 06:36 AM

I think X sounds like what I want: shutter speed at 1/180, manual aperture and ISO, is that correct? I don't have the camera with me...

RBellavance · 05-20-2010, 07:02 AM

Originally posted by dnmtsn`

I think X sounds like what I want: shutter speed at 1/180, manual aperture and ISO, is that correct? I don't have the camera with me...

That is correct.

**Aristophanes** · 05-20-2010, 07:12 AM

Originally posted by RBellavance

That is correct.

And does X mode work with M lenses? No camera here at work, but curious.

RBellavance · 05-20-2010, 07:31 AM

Originally posted by Aristophanes

And does X mode work with M lenses? No camera here at work, but curious.

Never tried that. As a matter of fact, I've never really used X mode.

rockmaster1964 · 05-20-2010, 10:40 AM

Yes X mode will work with M lenses.

Russell-Evans · 05-20-2010, 12:38 PM

Originally posted by RBellavance

Tv (but you give up control of the aperture)

If you put ISO control on one of the e-dials for Tv mode, you can control the aperture via the ISO setting, higher ISO, smaller aperture, lower ISO larger aperture. This can be done both with or without a flash.

Thank you
Russell

ll_coffee_lP · 05-20-2010, 01:31 PM

Originally posted by Lowell Goudge

What I do is set in manual mode when I want control, and then make my settings watching the light meter to see how much I want to have natural light and how much I want the flash to contribute

I'm a total flash newb (have always shot natural light), but am trying to learn about off camera flash (I now have radio triggers for this).

Can you explain what you've written above, as I get wildly inconsistent results with my flash (Sigma EF-500 DG Super and K-7)?

Set the camera on Manual - this is how I regularly shoot - check!
How do you set the flash levels to contribute? Is this done manually as well (i.e. set at 1/4 power, etc.)?

Curious how you do this.

Any help would be appreciated.

c[_]

RBellavance · 05-20-2010, 01:31 PM

Originally posted by Russell-Evans

If you put ISO control on one of the e-dials for Tv mode, you can control the aperture via the ISO setting, higher ISO, smaller aperture, lower ISO larger aperture. This can be done both with or without a flash.

Of course, and the converse it true in Av mode (in fact, that is how my camera is setup).

dnmtsn` · 05-25-2010, 02:16 AM

I tried the X mode and it does what I wanted - it allows me to shoot at the highest shutter speed available with flash and I can control ISO with one wheel and aperture with the other.

The problem now is that P-TTL doesn't seem to work at all in setting the flash power to produce a correct exposure; or I don't understand it. I would expect that P-TTL would not allow over-exposed shots, but it well does. When in X mode I have to adjust exposure by stopping down the lens (ISO is already at 100), or I get overexposed shots. I would expect the flash to output just the amount of light that is needed, but this doesn't happen. Is this how things are supposed to work, am I missing something here?
Thanks,
dan

**Lowell Goudge** · 05-25-2010, 02:47 AM

What I meant in my previous post and flash control is the following

your flash power used in a photo will be based upon the ratio of flash to natural lighting in the shot

I use flash for three main reasons, to isolate the subject from the background, to stop motion and to fill in shadow detail

in the first two cases you want the flash to contribute the majority of the illumination and in manual I will set the exposure so that natural lighting is about three or four stops under exposed. In the last case, I might manually set the exposure to almost perfect or under by 1-2 stops depending on how much shadow detail I want to bring out.

You will need to experiment somewhat to get the feel for it

05-14-2010, 04:51 AM	#1
dnmtsn` Inactive Account Join Date: Sep 2008 Location: Romania Posts: 36	K7 Shutter speed with flash in Av Hi. I tried to find an answer using the search but nothing came up. I am using my K7 with a Metz 48 flash in Av, with the Metz installed on the camera. My problem is that in this setup the K7 always sets the shutter speed at 1/60. I have no idea why that happens as maximum flash sync speed is faster than that. Is there a way to have it set the shutter speed to the maximum 1/180 in this setup? I know I can get that using M but I would like to have it in Av. Thanks, Dan

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05-14-2010, 05:19 AM	#2
rockmaster1964 Veteran Member Join Date: Oct 2008 Location: Frisco Texas Photos: Gallery Posts: 382	In Av the camera will set the shutter speed based on the focal length of the lens. If you want it at 1/180 all the time put the camera in X and then set your aperture.

05-14-2010, 06:10 AM	#3
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,887	As noted by rockmaster1964 the pentax cameras will, if the lens is an AF lens, set shutter speed to match focal length when in AV mode. If you enable auto ISO it will attempt to make the exposure you need with natural light first, then add flash accordinglyu so you are not really in control. What I do is set in manual mode when I want control, and then make my settings watching the light meter to see how much I want to have natural light and how much I want the flash to contribute

05-20-2010, 03:17 AM	#4
dnmtsn` Inactive Account Join Date: Sep 2008 Location: Romania Posts: 36 Original Poster	this is revealing, thanks a lot. I had no idea about the connection between focal length and shutter speed in Av. Is this documented in the user manual, or is it general knowledge? Indeed, if I use a 50mm lens, the speed is set at 1/90; it's 1/60 with a 35mm. I will try to do what you suggested.

05-20-2010, 05:42 AM	#5
RBellavance Veteran Member Join Date: Nov 2006 Location: Near Montréal, Canada Photos: Gallery Posts: 1,716	In Av, you "give up" control of the shutter speed (just like you "give up" control of the aperture in Tv). If you need a specific shutter speed, you have three choices: - M (complete control, and what I normally use with a flash) - TAv (like M but with Auto ISO) - X (shutter fixed 1/180s) - Tv (but you give up control of the aperture)

05-20-2010, 06:36 AM	#6
dnmtsn` Inactive Account Join Date: Sep 2008 Location: Romania Posts: 36 Original Poster	I think X sounds like what I want: shutter speed at 1/180, manual aperture and ISO, is that correct? I don't have the camera with me...

05-20-2010, 07:02 AM	#7
RBellavance Veteran Member Join Date: Nov 2006 Location: Near Montréal, Canada Photos: Gallery Posts: 1,716	Originally posted by dnmtsn` I think X sounds like what I want: shutter speed at 1/180, manual aperture and ISO, is that correct? I don't have the camera with me... That is correct.

05-20-2010, 07:12 AM	#8
Aristophanes Site Supporter Join Date: Jul 2008 Location: Rankin Inlet, Nunavut Photos: Albums Posts: 3,948	Originally posted by RBellavance That is correct. And does X mode work with M lenses? No camera here at work, but curious.

05-20-2010, 07:31 AM	#9
RBellavance Veteran Member Join Date: Nov 2006 Location: Near Montréal, Canada Photos: Gallery Posts: 1,716	Originally posted by Aristophanes And does X mode work with M lenses? No camera here at work, but curious. Never tried that. As a matter of fact, I've never really used X mode.

05-20-2010, 10:40 AM	#10
rockmaster1964 Veteran Member Join Date: Oct 2008 Location: Frisco Texas Photos: Gallery Posts: 382	Yes X mode will work with M lenses.

05-20-2010, 12:38 PM	#11
Russell-Evans Veteran Member Join Date: Nov 2007 Posts: 1,553	Originally posted by RBellavance Tv (but you give up control of the aperture) If you put ISO control on one of the e-dials for Tv mode, you can control the aperture via the ISO setting, higher ISO, smaller aperture, lower ISO larger aperture. This can be done both with or without a flash. Thank you Russell

05-20-2010, 01:31 PM	#12
ll_coffee_lP Inactive Account Join Date: Jan 2008 Location: Ontario, Canada Posts: 1,972	Originally posted by Lowell Goudge What I do is set in manual mode when I want control, and then make my settings watching the light meter to see how much I want to have natural light and how much I want the flash to contribute I'm a total flash newb (have always shot natural light), but am trying to learn about off camera flash (I now have radio triggers for this). Can you explain what you've written above, as I get wildly inconsistent results with my flash (Sigma EF-500 DG Super and K-7)? Set the camera on Manual - this is how I regularly shoot - check! How do you set the flash levels to contribute? Is this done manually as well (i.e. set at 1/4 power, etc.)? Curious how you do this. Any help would be appreciated. c[_]

05-20-2010, 01:31 PM	#13
RBellavance Veteran Member Join Date: Nov 2006 Location: Near Montréal, Canada Photos: Gallery Posts: 1,716	Originally posted by Russell-Evans If you put ISO control on one of the e-dials for Tv mode, you can control the aperture via the ISO setting, higher ISO, smaller aperture, lower ISO larger aperture. This can be done both with or without a flash. Of course, and the converse it true in Av mode (in fact, that is how my camera is setup).

05-25-2010, 02:16 AM	#14
dnmtsn` Inactive Account Join Date: Sep 2008 Location: Romania Posts: 36 Original Poster	I tried the X mode and it does what I wanted - it allows me to shoot at the highest shutter speed available with flash and I can control ISO with one wheel and aperture with the other. The problem now is that P-TTL doesn't seem to work at all in setting the flash power to produce a correct exposure; or I don't understand it. I would expect that P-TTL would not allow over-exposed shots, but it well does. When in X mode I have to adjust exposure by stopping down the lens (ISO is already at 100), or I get overexposed shots. I would expect the flash to output just the amount of light that is needed, but this doesn't happen. Is this how things are supposed to work, am I missing something here? Thanks, dan

05-25-2010, 02:47 AM	#15
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,887	What I meant in my previous post and flash control is the following your flash power used in a photo will be based upon the ratio of flash to natural lighting in the shot I use flash for three main reasons, to isolate the subject from the background, to stop motion and to fill in shadow detail in the first two cases you want the flash to contribute the majority of the illumination and in manual I will set the exposure so that natural lighting is about three or four stops under exposed. In the last case, I might manually set the exposure to almost perfect or under by 1-2 stops depending on how much shadow detail I want to bring out. You will need to experiment somewhat to get the feel for it