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07-06-2012, 10:32 AM   #16
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Thank you for making this clear. So now I can stop trying and cleaning the contacts.

BTW, do you know if it is the problem only refer to K-5 or a common problem to any pentax camera? For some reason, I remember it worked fine on k-x, but I could be wrong. When I go back to check the kept pictures that I took with fill flash, the shutter speed were below 180.

And also is this a problem for AF360 only? Sounds like the AF540 works fine.

07-06-2012, 08:03 PM - 1 Like   #17
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QuoteOriginally posted by grahame Quote
I tried Tv model on K-5 last night, still the same result, over-exposed.

Is there any other setting on the camera or flash that I don't know?

Thank you for any suggestions.
I cannot duplicate the problems you are seeing. I just set the ISO manually and the camera to Tv mode. I adjusted the ISO upwards until the camera metered for a reasonable aperture with the shutter speed fixed at 1/500.

I turned on my AF540 and set it to HSS and took a shot in my backyard with some shaded and sunlit areas. The camera exposed well and the flash filled the shaded areas.

I just looked at the AF360 manual and it appears that the 360 and 540 have a very similar layout and that HSS works just as described in the 540 manual: You simply set the flash switch on the rear as far right as it will go, which is HSS mode, and whenever the camera shutter speed is higher than 1/180, the flash uses HSS.

The manual lists not having HSS in P (they call it programmed AE) mode as the only imitation (other than reduced flash output in HSS mode).

I will scroll through my settings to see if there is anything specific relative to HSS, but off the top of my head, I do not think there is anything in the menus that should affect this.

Ray
07-06-2012, 08:26 PM   #18
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QuoteOriginally posted by Ray Pulley Quote
I cannot duplicate the problems you are seeing. I just set the ISO manually and the camera to Tv mode. I adjusted the ISO upwards until the camera metered for a reasonable aperture with the shutter speed fixed at 1/500.

I turned on my AF540 and set it to HSS and took a shot in my backyard with some shaded and sunlit areas. The camera exposed well and the flash filled the shaded areas.

I just looked at the AF360 manual and it appears that the 360 and 540 have a very similar layout and that HSS works just as described in the 540 manual: You simply set the flash switch on the rear as far right as it will go, which is HSS mode, and whenever the camera shutter speed is higher than 1/180, the flash uses HSS.

The manual lists not having HSS in P (they call it programmed AE) mode as the only imitation (other than reduced flash output in HSS mode).

I will scroll through my settings to see if there is anything specific relative to HSS, but off the top of my head, I do not think there is anything in the menus that should affect this.

Ray

Thank you, Ray.

What you have done here is exactly what I did. And actually I can see the symbol of HSS showing on the LCD screen of the flash when the shutter speed is faster than 180.

What's the metering model did you use? multi-segment, center or spot? I usually set at center or spot. I wonder if that make difference. I can give it a try on all three models tomorrow.

Or maybe the design of 360 has problem to begin with. From all replies here, 540s are fine and 360s have problem, although the manual doesn't seem to be much different form 540.

Anyone else tried 360 on HSS model?
07-06-2012, 08:40 PM   #19
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QuoteOriginally posted by grahame Quote
Thank you, Ray.

What you have done here is exactly what I did. And actually I can see the symbol of HSS showing on the LCD screen of the flash when the shutter speed is faster than 180.

What's the metering model did you use? multi-segment, center or spot? I usually set at center or spot. I wonder if that make difference. I can give it a try on all three models tomorrow.

Or maybe the design of 360 has problem to begin with. From all replies here, 540s are fine and 360s have problem, although the manual doesn't seem to be much different form 540.

Anyone else tried 360 on HSS model?
You may have hit on the problem!

It is the metering mode. I always shoot flash in multi-segment mode. When I switched to center the shot was very over-exposed. Spot was similar, but that can depend upon what is under the spot.

I have a vague memory of this issue, but cannot find anything about it in the manual so far.

Try using multi-segment mode.

Ray

07-06-2012, 09:06 PM   #20
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No luck. tried multi-segment metering, still over exposed.

I hope I can borrow a 540 and try it on my k-5, to see if it is the camera problem.

one more possibility: Is there an up-limit for aperture in filling flash? I mean can I use large aperture for HSS? i am kind of confused now: I remember when using a manual flash, the exposure is decided by aperture, only, and the shutter speed, once slower than sync speed, doesn't affect exposure. But HSS might be different, and PTTL might be different again. PTTL should measure the really situation in the re-flash.

Maybe just a design problem.
07-09-2012, 05:52 AM   #21
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The HSS works, in that the shutter will release for shutter speeds faster than 1/180s, and the frame is completely lit. However the P-TTL part, which meters the flash to obtain proper exposure, including exposure compensation to balance the flash and ambient light, does not appear to work. As I said in a previous post, Pentax "support" confirmed the issue, said they knew about it and said that it is a "hardware limitation" of the K-5. He also said that there is no firmware update that they know of which can fix the problem.

As a point of reference, I used the exact same technique with my Pentax K100D Super for years, with the same 50mm lens, and same 360AF flash. With that model you can perfectly dial in the amount of fill flash relative to the ambient light. It's a basic function, a fundamental technique... I can't believe that they didn't test it on the K-5.

I will have to run some comparisons with FEV+/-, EV+/-, comparing the K100 and K5, for different metering modes and see what's really going on. But I don't have much hope for "solving" the problem.
07-09-2012, 11:42 AM   #22
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QuoteOriginally posted by gpellegrinetti Quote
knew about it and said that it is a "hardware limitation" of the K-5.
Do you mean it is a problem found on K-5-AF360 combination only? It looks like 540 works fine on K-5, and 360 worked fine on k-x, to my experience although it could be wrong.

That is sad.
07-09-2012, 02:07 PM - 3 Likes   #23
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I have a K-5 and 360 and have encountered no real issues.

See whether everything is basically working (I'll assume you're indoors):
  • Set your camera to manual mode
  • Select, for example, F5.6 aperture, 1/180 shutter speed and 100 ISO. The exposure meter on the back should go off the scale (you'll be around 5EV or more underexposed)
  • Take a shot: P-TTL should do its thing and give you a correct exposure (it should work when you're using bounce too).
If this is blowing everything out to white, you have an issue either with the flash or the body.

If you use HSS, you'll probably have to dial in positive flash compensation as you reduce the shutter speed.

Av, in my experience, is not good for flash. Manual is the correct mode if you think about it: you dial in the values that you would like (low ISO, fast shutter, aperture to taste) and then let the flash actually make that exposure possible.

Something else that strikes me: if you're trying to use fill flash, you may be hitting the lower limit of flash output, Minimum output on the AF360 is 1/32 full output and this may well be too bright.

07-10-2012, 09:20 AM   #24
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QuoteOriginally posted by top-quark Quote
Av, in my experience, is not good for flash. Manual is the correct mode if you think about it: you dial in the values that you would like (low ISO, fast shutter, aperture to taste) and then let the flash actually make that exposure possible.
You are definitely right! It looks the Pentax camera doesn't talk to flash in the way we though. In Av mode, came has set a correct speed for the aperture we set already, a flash, even a p-ttl one, doesn't tell the camera how much light it is going to give and let the camera to adjust accordingly.

Yes, manual mode, make sure the setting is under-exposed if without flash, and flash will give the right amount of light for correct exposure, even at HSS. K-5 and AF360.

I wonder why the manual says HSS works at Tv. Maybe it means manual mode on the flash, but not P-TTL mode?

Thank you, top-quark!
07-10-2012, 10:02 AM   #25
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QuoteOriginally posted by top-quark Quote
I have a K-5 and 360 and have encountered no real issues.
Av, in my experience, is not good for flash. Manual is the correct mode if you think about it: you dial in the values that you would like (low ISO, fast shutter, aperture to taste) and then let the flash actually make that exposure possible.

Something else that strikes me: if you're trying to use fill flash, you may be hitting the lower limit of flash output, Minimum output on the AF360 is 1/32 full output and this may well be too bright.
I think these two together is close to the right Idea - but not the full story. Just tried a few things now, K5 and AF360. Yup, I can still provoke overexposure even with the camera in Manual under some circumstances (the combination of a white subject, bounce, wide open aperture and not using HSS seems the worst case).

I too was wondering if the overexposure is related to the minimum flash discharge - There's two observations against that from my testing here: setting -1.5 Flash compensation fixes the overexposure, and I don't seem to notice a really short recycle time on the flash in these circumstances.

That said, HSS works OK it seems - and that helps with flexibility on the shutter speed. I can't help but think you can't really use K5 and AF360 as indiscriminately as I would like to...... But maybe that's not a bad thing!
07-10-2012, 06:35 PM   #26
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I picked up a k-5 today and am having overexposure issues. I did what top-quark suggested, but it was still way overexposed. shooting in a basically dark room 1/100, f/5.0, 100iso I still need -2 to compensate. It seems to only happen when I'm bouncing the light. I've been reading for hours on these forums about fixes. I don't like using flash compensation because the problem only exists when bouncing the light.
07-11-2012, 03:35 PM - 2 Likes   #27
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Here are some test shots that I made this evening in my living room with the blinds closed and the light off. Just enough light to autofocus. Attempting to show how the flash interacts with various exposure modes.

I used a convenient (and serene) model with the following setup:
  • K-5
  • DA* 16-50mm at 50mm
  • AF-360FGZ flash with a Sto-Fen Omnibounce
  • Flash exposure compensation of -0.3 EV (for taste)
I use the Omnibounce because I like the even illumination that it produces (much better than just pointing the flash at the ceiling), even though it reduces the effective guide number. If you've not used one, it only works indoors: outside there are generally no surfaces to bounce off.

For reference, here's a shot without flash: F5.6, 1/25, ISO 12800.

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On hindsight, I should have dialled in some positive exposure compensation, because my subject was bright - so many things to remember!

Started off in manual mode and went round the dial.

Manual mode: F5.6, 1/80, ISO 100.

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TAv: F5.6, 1/80, ISO 25600!

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Av: F5.6, 1/100, ISO 100.

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Tv: F2.8, 1/80, IS0 100.

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Sv: F2.8, 1/100, ISO 100.

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Observations. By and large, P-TTL is doing its job admirably. All but one are decently exposed. TAv was an absolute disaster because ISO is set automatically to expose without flash and you can't change it. It's a good mode for outdoors, but not so good indoors and rotten for flash photography. The modes where you can't control the shutter speed have the shutter set to 1/100. In actual fact, the shutter speed is set according to lens focal length - at 24mm I'd get 1/50. The modes where you can't control aperture have aperture set to wide open and you can't change this. In case you're interested, green mode didn't look so hot (F7.1, 1/100, ISO 3200), but it was a lot better than TAv. Anyway, we don't use green mode round here, do we? We can conclude that manual mode is the best because it is the only one that gives you control over all shooting parameters.

Now for HSS.

There is definitely an issue using this in Tv mode on the K-5. When you attempt to dial shutter speeds faster than 1/180, the camera stops for a few seconds before setting the shutter speed. This horrible input lag means that you can't really control the shutter speed - you'll just end up with something slightly random; turning the front control dial sets you back to 1/180. Manual mode has no such problem - yet another good reason to use manual with flash.

When using high speed sync, the flash has a shorter duration, which has quite an effect on the guide number. The 360 has a guide number of 30 at the 50mm length I was using. Engage HSS and this drops to 13.4 at 1/250. I don't know whether it's a limitation of the K-5 or P-TTL (I suspect the latter) but there is no automatic compensation for this loss of light. The way to increase the effective guide number is to bump up the ISO. Here are a couple of sample shots, both in manual mode:

F4, 1/500, ISO 800.

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F4, 1/1000, ISO 1600.

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These are actually pretty good. Being able to get 1/1000 indoors at a perfectly usable ISO 1600 is simply amazing. And the 360 costs a lot less than an F1.2 lens! The exposures are a bit brighter than the earlier ones, but that's because I didn't calculate the exposure, simply made an educated guess. It's good enough, particularly since I could have tweaked the exposure in post had I so desired.

I hope people find this useful and I also hope that I've shown that there are no fundamental issues with using P-TTL flash. So long as you're aware of a couple of quirks, such as the interaction with different shooting modes and the issues with HSS, you should get pleasing results first time, every time. And I highly recommend the Sto-Fen.

People with blown-out photographs, please post examples with details of settings and the lens used and let's see whether we can diagnose your issues.
07-11-2012, 05:42 PM   #28
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QuoteOriginally posted by top-quark Quote
People with blown-out photographs, please post examples with details of settings and the lens used and let's see whether we can diagnose your issues.
I will do that when I have a chance. It's going to look a lot like this:

https://www.pentaxforums.com/forums/pentax-k-5/171474-firmware-v1-12-23-20-a-4.html#post1780208

That's my post from six months ago. Firmware 1.13 hasn't made any difference.

Since I took those shots, I also determined that bounced P-TTL wireless flash exposes correctly. The problem only occurs with on-camera bounce flash.

Lens was a Sigma 24-60mm f/2.8 - that's the only normal-range autofocus autoexposure lens I have. Other exposure details are in the old linked post.

I have reproduced the test with a borrowed Pentax DA-L 55-300 and Metz AF50 flash with substantially the same poor results.
07-11-2012, 09:29 PM   #29
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K-5, FGz 360 with Sto-Fen Omnibounce, Sigma prime 28mm F1.8 lens, flash is being bounced off of a white ceiling at night (12:31am), only other light source is light from attached bathroom.
Here is Manual mode - 1/200, F4.0, ISO 200-6400, 100
P-TTL, HSS
Photo Album - Imgur

It goes ISO 200, ISO 400, ISO 800, ISO 1600, ISO 3200, ISO 6400, ISO 100
I don't know why it moved ISO 100 to the end. My walls are a light brown, probably most accurate in ISO 200/100.

Manual: 1/50 F2.8 ISO 400-12800, 100
P-TTL
Photo Album - Imgur

It goes once again oddly - 400, 1600, 6400, 12800, 100

Last edited by Salmoon; 07-11-2012 at 09:34 PM.
07-12-2012, 08:35 PM   #30
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@Quicksand

I checked out those images. The ones with bounce flash look absolutely horrible.

Question for you: do you have to provoke this issue? For example, if you photograph something at camera level with the flash head pointing straight up is it still blown out to all hell? I noticed certain characteristics of your test shots, particularly that they were taken at a downward angle, meaning that bounce doesn't necessarily hit the ceiling.

I tried to reproduce the effect you were seeing. I must be really rubbish at this, because try as I might, I couldn't manage a really bad exposure. All images shot in Av mode, F4.5, 50mm, flash head pointing straight up.

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Thought I'd try putting the clementine on the floor. Still more than adequate.

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Switched over to the 55-300mm. That is not a good lens indoors. I had to stand on tippy toes on my sofa to get the necessary focus distance. No success in getting a bad exposure though.

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I did, however, manage to get a blown out exposure using the Sto-Fen (flash head at 45 degrees):

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Reducing ISO to 100 changed the exposure considerably.

View Picture EXIF
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The fact that knocking the ISO down reduced the over-exposure means that this was not measured flash exposure (P-TTL should give you a consistent exposure so long as you're not hitting the lower or upper limits of the flash output). Here's what I think was happening: none (or not enough) of the bounced pre-flash was reaching the exposure meter so I simply got a full power blast. We have the same camera and same flash so we should be getting the same results. If you're getting blown out photographs no matter how you shoot, you likely have a faulty flash unit - it does not seem to be a camera firmware issue. You can get around it by using the flash in manual.

In the same thread that you linked to, I was quite amused to read this:
QuoteOriginally posted by Lage Quote
Tilted flash still overexposures. Metz 58 AF-1. Never had an overexposured image with the same flash on my K100D Super.
How hard can it be PENTAX/RICOH???
I think IŽll look for another brand now. Sad moment for a pentax shooter since -81.
What a twat!

@Salmoon

Can't really see what's wrong. First batch has only two bad exposures: the ones at ISO 6400 and 100. I showed above that HSS needs some manual adjustment to compensate for loss of light (so ISO 100 is under-exposed) but not too much, clearly. As for the second batch you've got over-exposure at ISO 6400 and 12800. At minimum output, the 360 is going to have a guide number of 1 at ISO 100. Photos look like they're shot from about 1 metre. I suspect that ISO 6400 and 12800 are coming up against the lower limit of flash output.

Since you don't have to use ISO 6400 or 12800, you don't have a problem. "I get over-exposed photographs when I over-expose them" is kinda what you're complaining about.
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