K-70 newbie, exposure and flash question

Bauie · 04-19-2022, 06:34 PM

Just an update. The flash and camera seem to like each other when I put the camera on full AUTO. The problem seems to occur in AE mode.

**Des** · 04-20-2022, 09:05 PM

Originally posted by Bauie

The flash and camera seem to like each other when I put the camera on full AUTO. The problem seems to occur in AE mode.

Good that they have made friends, but it is curious. You might want to experiment with other modes as well like M, Av and TAv.

**photogem** · 04-20-2022, 11:09 PM

Originally posted by Des

Originally posted by Bauie

Just an update. The flash and camera seem to like each other when I put the camera on full AUTO. The problem seems to occur in AE mode.

Good that they have made friends, but it is curious. You might want to experiment with other modes as well like M, Av and TAv.

I wasn't aware there is an AE-L (Auto-Exposure-Lock) mode, not saying one couldn't call it somehow a mode as well.

Pentax has some very special modes, such as P and Tav.
Full AUTO is of course the worst, better to use P (Hyper-Program) which is AUTO at the beginning and then you override it and have Tv and Av. Not as advanced in the K70 as in the K5/3 etc. which allow "mtf" as well.

**Des** · 04-21-2022, 12:30 AM

Originally posted by photogem

I wasn't aware there is an AE-L (Auto-Exposure-Lock) mode, not saying one couldn't call it somehow a mode as well.

The OP didn't say "AE-L mode" but AE mode: might have meant Av mode.

What puzzles me is why it would work effectively in "full Auto" (which I take to mean AUTO on the mode dial) but not another mode setting. Unless it's about the FEC - which applies in all modes except AUTO.

Or perhaps they mean the AE metering settings (Spot, centre-weighted, multi-segment)? That might make a difference.

Last edited by Des; 04-21-2022 at 12:37 AM.

Bauie · 04-21-2022, 05:39 AM

Sorry, I typed wrong. It was on Av, Aperture Priority mode.

**Des** · 04-21-2022, 03:27 PM

Originally posted by Bauie

It was on Av, Aperture Priority mode.

Did you check the Flash Exposure Compensation setting? It affects exposure on Av mode (and other modes) but not Auto mode. If FEC was in the + ranges, that could explain the difference in flash output between those modes (assuming the settings on the flash itself haven't changed).

Bauie · 05-02-2022, 05:39 PM

Just wondering if there is a way to tell the camera to underexpose all images by 1/3rd stop without manually doing it ever time I turn the camera on.

wadge22 · 05-02-2022, 06:12 PM - **1 Like**

Originally posted by Bauie

Just wondering if there is a way to tell the camera to underexpose all images by 1/3rd stop without manually doing it ever time I turn the camera on.

In the menu number 5, there's an option called "Memory." Once you select memory, there are three pages of check boxes for different options, checking them means that function will stay the same when you turn the camera off then back on, unchecked means they reset to default every time it's turned off. You want EV Compensation checked, it's on the first page.

Bauie · 05-03-2022, 05:43 AM - **2 Likes**

Thanks so much Des and wadge22. Flash compensation was off. I've found that if I have a light modifier on the flash is when I have the problem. If I take it off I get pretty good exposure.

**cdw2000** · 05-16-2022, 01:30 PM

I had a similar issue with my Metz flash over exposing on my K-70. It turns out I had the camera set to Auto-ISO in P mode and the camera was using the max. ISO of 3200. I think the exposure was beyond the flash's capability to reduce the power level. Check your over-exposed flash shots to see what ISO was used.

**Des** · 05-16-2022, 03:41 PM

Originally posted by cdw2000

I had the camera set to Auto-ISO in P mode and the camera was using the max. ISO of 3200. I think the exposure was beyond the flash's capability to reduce the power level.

In P mode, with a PTTL flash, by default the camera will try to minimise the difference between the ambient light and the flash exposure. In other words, it will use a high ISO and use no more flash output than is necessary to bring the exposure to the required level. It you don't want that, you can lower the maximum ISO or use M mode. (There might be a way to do it in the P-line setting too, with a camera that lets you set the P-line priority, like the KP or K-3 series.)

If the camera was over-exposing in P mode, it suggests that either:
1. FEC on the camera was too high.
2. The output setting on the flash was too high. (The flash can be set to fire +/- in TTL mode. I usually set mine to -0.7EV by default and adjust as required.)
3. Exposure compensation in the camera (that is, general exposure compensation, not FEC) was too high.
4. The PTTL system wasn't metering properly (whether because of the flash or because of the camera). The AE mode chosen (centre point, centre-weighted or matrix) could affect this.

The flash should be capable of being reduced to very low output levels, as is the case when the flash is in manual mode (usually goes down to 1/128 or 1/256). Of course there may be situations in which any flash output at all would cause overexposure. But if the metering is correct and there is no exposure compensation on the camera or flash, that should not occur at the top of the range of a floating ISO. The camera should adjust the ISO (and other parameters if there is room to do so) so that it doesn't overexpose when the flash is fired.

04-20-2022, 11:09 PM	#18
photogem Site Supporter Join Date: Apr 2015 Posts: 3,520	Originally posted by Des Originally posted by Bauie Just an update. The flash and camera seem to like each other when I put the camera on full AUTO. The problem seems to occur in AE mode. Good that they have made friends, but it is curious. You might want to experiment with other modes as well like M, Av and TAv. I wasn't aware there is an AE-L (Auto-Exposure-Lock) mode, not saying one couldn't call it somehow a mode as well. Pentax has some very special modes, such as P and Tav. Full AUTO is of course the worst, better to use P (Hyper-Program) which is AUTO at the beginning and then you override it and have Tv and Av. Not as advanced in the K70 as in the K5/3 etc. which allow "mtf" as well. Last edited by photogem; 04-20-2022 at 11:23 PM.

05-16-2022, 03:41 PM	#26
Des Loyal Site Supporter Join Date: Jan 2014 Location: Victoria Australia Photos: Albums Posts: 6,423	Originally posted by cdw2000 I had the camera set to Auto-ISO in P mode and the camera was using the max. ISO of 3200. I think the exposure was beyond the flash's capability to reduce the power level. In P mode, with a PTTL flash, by default the camera will try to minimise the difference between the ambient light and the flash exposure. In other words, it will use a high ISO and use no more flash output than is necessary to bring the exposure to the required level. It you don't want that, you can lower the maximum ISO or use M mode. (There might be a way to do it in the P-line setting too, with a camera that lets you set the P-line priority, like the KP or K-3 series.) If the camera was over-exposing in P mode, it suggests that either: 1. FEC on the camera was too high. 2. The output setting on the flash was too high. (The flash can be set to fire +/- in TTL mode. I usually set mine to -0.7EV by default and adjust as required.) 3. Exposure compensation in the camera (that is, general exposure compensation, not FEC) was too high. 4. The PTTL system wasn't metering properly (whether because of the flash or because of the camera). The AE mode chosen (centre point, centre-weighted or matrix) could affect this. The flash should be capable of being reduced to very low output levels, as is the case when the flash is in manual mode (usually goes down to 1/128 or 1/256). Of course there may be situations in which any flash output at all would cause overexposure. But if the metering is correct and there is no exposure compensation on the camera or flash, that should not occur at the top of the range of a floating ISO. The camera should adjust the ISO (and other parameters if there is room to do so) so that it doesn't overexpose when the flash is fired. Last edited by Des; 05-17-2022 at 02:56 PM.

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04-19-2022, 06:34 PM	#16
Bauie Junior Member Join Date: Aug 2019 Location: Woodend, Victoria Photos: Albums Posts: 44 Original Poster	Just an update. The flash and camera seem to like each other when I put the camera on full AUTO. The problem seems to occur in AE mode.

04-20-2022, 09:05 PM	#17
Des Loyal Site Supporter Join Date: Jan 2014 Location: Victoria Australia Photos: Albums Posts: 6,423	Originally posted by Bauie The flash and camera seem to like each other when I put the camera on full AUTO. The problem seems to occur in AE mode. Good that they have made friends, but it is curious. You might want to experiment with other modes as well like M, Av and TAv.

04-21-2022, 12:30 AM	#19
Des Loyal Site Supporter Join Date: Jan 2014 Location: Victoria Australia Photos: Albums Posts: 6,423	Originally posted by photogem I wasn't aware there is an AE-L (Auto-Exposure-Lock) mode, not saying one couldn't call it somehow a mode as well. The OP didn't say "AE-L mode" but AE mode: might have meant Av mode. What puzzles me is why it would work effectively in "full Auto" (which I take to mean AUTO on the mode dial) but not another mode setting. Unless it's about the FEC - which applies in all modes except AUTO. Or perhaps they mean the AE metering settings (Spot, centre-weighted, multi-segment)? That might make a difference. Last edited by Des; 04-21-2022 at 12:37 AM.

04-21-2022, 05:39 AM	#20
Bauie Junior Member Join Date: Aug 2019 Location: Woodend, Victoria Photos: Albums Posts: 44 Original Poster	Sorry, I typed wrong. It was on Av, Aperture Priority mode.

04-21-2022, 03:27 PM	#21
Des Loyal Site Supporter Join Date: Jan 2014 Location: Victoria Australia Photos: Albums Posts: 6,423	Originally posted by Bauie It was on Av, Aperture Priority mode. Did you check the Flash Exposure Compensation setting? It affects exposure on Av mode (and other modes) but not Auto mode. If FEC was in the + ranges, that could explain the difference in flash output between those modes (assuming the settings on the flash itself haven't changed).

05-02-2022, 05:39 PM	#22
Bauie Junior Member Join Date: Aug 2019 Location: Woodend, Victoria Photos: Albums Posts: 44 Original Poster	Just wondering if there is a way to tell the camera to underexpose all images by 1/3rd stop without manually doing it ever time I turn the camera on.

05-02-2022, 06:12 PM - 1 Like	#23
wadge22 Veteran Member Join Date: Jun 2021 Location: NE Ohio Photos: Albums Posts: 897	Originally posted by Bauie Just wondering if there is a way to tell the camera to underexpose all images by 1/3rd stop without manually doing it ever time I turn the camera on. In the menu number 5, there's an option called "Memory." Once you select memory, there are three pages of check boxes for different options, checking them means that function will stay the same when you turn the camera off then back on, unchecked means they reset to default every time it's turned off. You want EV Compensation checked, it's on the first page.

05-03-2022, 05:43 AM - 2 Likes	#24
Bauie Junior Member Join Date: Aug 2019 Location: Woodend, Victoria Photos: Albums Posts: 44 Original Poster	Thanks so much Des and wadge22. Flash compensation was off. I've found that if I have a light modifier on the flash is when I have the problem. If I take it off I get pretty good exposure.

05-16-2022, 01:30 PM	#25
cdw2000 Site Supporter Join Date: Aug 2020 Location: New Hampshire Photos: Albums Posts: 244	I had a similar issue with my Metz flash over exposing on my K-70. It turns out I had the camera set to Auto-ISO in P mode and the camera was using the max. ISO of 3200. I think the exposure was beyond the flash's capability to reduce the power level. Check your over-exposed flash shots to see what ISO was used.