[Digitalis]

but the point is that it SUPPOSED to work also in AUTO mode

True, It is supposed to work but flash metering is a tricky thing and even the best TTL exposure systems only get things right 90% of the time*. When I'm using studio flash for commercial work or outdoors I prefer manual control of flash and camera.

*Unless you have ever worked with OTF (off the film) metering system that was used in the Pentax LX is freakishly accurate, even when using flash I have never seen it stuff a shot up. Sadly this metering technology is impossible to use on digital.

[WPRESTO]

OK, I ran multiple tests under the conditions described below, with my findings at the end.

SUBJECT: small figurine of near neutral tone and reflectivity with a neutral gray card close behind, oriented near perpendicular to the line-of-sight
DISTANCES: either about 4 feet or about 12 inches
CAMERAS: used both K3 and K5
CAMERA SETTING: AV, X, and MANUAL, and if in manual, shutter speed set at max for flash
ISO: either 100 (K3) or 160 (K5)
APERTURE: set through the camera over several different stops: f4, f5.6; f8; f9; f11, f16; f22
LENSES: four different macro lenses: 35mm f2.8 DA; 50mm SMCA; Voigtlander 125mm f2.5; Pentax 200mm SMCA ED

RESULTS:
1. AT A DISTANCE OF FOUR FEET, WITH ALL OF THE LENSES EXCEPT the 35mm DA, EXPOSURE VARIED WITH THE F-STOP SELECTED, typically from impossibly overexposed to correct, to underexposed (at f22)
2. AT A DISTANCE OF 12 INCHES, ALL of the lenses EXCEPT the 35MM DA overexposed badly at every f-stop although the image was approaching visibility at f22. The 35mm DA provided correct exposure at smaller f-stops, but overexposed starting about f8.
3. When I moved still closer to the subject with the 35mm DA attached, essentially getting into the true macro range for that lens, all images were eventually overexposed probably because the distance was less than the minimum for the flash.

I conclude that PTTL WILL NOT FUNCTION ON OLDER MANUAL-FOCUS SMC-A LENSES. When such a lens is mounted, the flash always fires a FULL blast when set to "AUTO."

For me, this means the flash is worthless as the whole point was to get PTTL flash exposure when stalking insects in the field, and the majority of my macro lenses are manual focus. The 35mm DA (also the 50mm) is primarily used inside in my "studio" where it's short working distance is frequently an advantage, and it is also a travel lens (small/light) used in museums where a longer lens would be too difficult to hand-hold. Most museums don't allow tripods or monopods for fear of other visitors tripping, and do not allow flash because it's a distraction and annoyance for other visitors. Also, I find AF more convenient for museum photography, for all my 30+ years using manual focus only but also the screens of AF cameras are not like the multi-prism I was accustomed to using.

[Digitalis]

small figurine of near neutral tone and reflectivity with a neutral gray card close behind, oriented near perpendicular to the line-or-sight

Could you post a picture of the small figurine?

A thought has occurred to me: do you have the internal camera flash exposure compensation set to zero?

[manntax]

True, It is supposed to work but flash metering is a tricky thing and even the best TTL exposure systems only get things right 90% of the time*. When I'm using studio flash for commercial work or outdoors I prefer manual control of flash and camera.

I noticed that shot you've prsented was already shared somewhere else back in 2013. Do you still have this flash ? If so - could you attempt taking a closeup macro shot with this ring flash and some of your 'A' lenses - in AUTo mode selected on flash, Manual mode on camera, 1/180th shutter and F8 selected in body with ISO on 100 ? And then post your findings ? With either K5 or K3 - both if possible ( maybe even K01 if you have one).

That will be of immense help in tracking down the problem with this ring flash on newer bodies. Thanks !

Could you post a picture of the small figurine?

I concur - seeing some photos would help !

I contacted Ricoh about this issue today. Sadly their response time seems to be terrible. I also contacted them about possible service to my Z1p body ( which I know is still supported by them ) and that was on 20th of Sept. - no response so far...

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Last edited by manntax; 09-26-2014 at 10:19 AM.

[Digitalis]

could you attempt taking a closeup macro shot with this ring flash and some of your 'A' lenses - in AUTo mode selected on flash, Manual mode on camera, 1/800th shutter and F8 selected in body with ISO on 100

1) Pentax K5IIs - in Manual mode - SMCP-A 50mm f/1.7 @ f/11 ISO 80 1/180th with manual 11mm extension tube AF160FC ringflash @ 1/16th power ( reference exposure)
2) Pentax K5IIs - in Manual mode - Sigma 180mm f/3.5 @ f/11 ISO 80 1/180th - AF160FC set to auto mode, no compensation, both tubes at equal ratio.
3) Pentax 10D - in X mode - Sigma 180mm f/3.5 @ f/11 ISO 80 1/180th - AF160FC set to auto mode, no compensation, both tubes at equal ratio.
4) Pentax K7 - in Manual mode - Sigma 180mm f/3.5 @ f/11 ISO 80 1/180th - AF160FC set to auto mode, no compensation, both tubes at equal ratio.

Subject was at a distance of 24 inches ( two feet) from the ringflash.

[manntax]

1) Pentax K5IIs - in Manual mode - SMCP-A 50mm f/1.7 @ f/11 ISO 80 1/180th with manual 11mm extension tube AF160FC ringflash @ 1/16th power ( reference exposure)

This one is also working - flash in 1/16 mode is delivering good exposure (see my sample above )

2) Pentax K5IIs - in Manual mode - Sigma 180mm f/3.5 @ f/11 ISO 80 1/180th - AF160FC set to auto mode, no compensation, both tubes at equal ratio.

This one - I have no experience with this lens. But I imagine that 180mm lens would keep the distance greater than in my case ( 100mm lens ) and F11 + ISO80 + smaller distance - perhaps it would work ok - especially in this dark background. Is there any chance you could try the flash in AUTo with something different - like Pentax F100mm macro or Pentax 50mm f2.8 macro lenses ? - these two I have and they both overexpose

3) Pentax 10D - in X mode - Sigma 180mm f/3.5 @ f/11 ISO 80 1/180th - AF160FC set to auto mode, no compensation, both tubes at equal ratio.

K10D gives my the same great results with whatever lens I use with this flash in both AUTO and manual mode.

4) Pentax K7 - in Manual mode - Sigma 180mm f/3.5 @ f/11 ISO 80 1/180th - AF160FC set to auto mode, no compensation, both tubes at equal ratio.

No experience with K7 - similar no other reports - could be ok as K10D is - or again could be the case that your 180mm lens is keeping the distance thats enough to not overexpose.

Subject was at a distance of 24 inches ( two feet) from the ringflash.

So - as per point 2) - any chance for your attempt to shot something with shorter macro ? The issue here is that the overexposure is directly linked with the distance between the subject and the elns. In case of 100mm and 50mm lenses (at 1:1 or 1:2 respectively ) my flash is nearly touching the subject - just 1-2 inches away !!! Your case of 24 inches !!! is like worlds apart - and I need to run the test with my K-01 but chances are that I would get good exposure too at this distance.

Thanks for taking your time to do these tests!

[WPRESTO]

Could you post a picture of the small figurine?

A thought has occurred to me: do you have the internal camera flash exposure compensation set to zero?

For the last round of tests desrcibed above: 1) the flash was set at "auto" with no exposure compensation; 2) the +/- metering compensation on both cameras was set at zero; 3) the flash output adjustment accessed via the camera's four-way controller was set at zero. Matrix metering was used (during the first round of testing I switched to spot metering twice but it made no visible difference to the exposure obtained immediately before using matrix). I dumped all the files from the two cards used, so I'd have to reassemble the set-up and repeat the test to post any images. I'm loath to do that because the flash has been packed away for a second time to be returned for a refund, and I'd rather not take it out again.
AGAIN, I conclude that PTTL WILL NOT FUNCTION with any manual SMCA lens. If anyone has obtained correct PTTL exposure using an AF160 and an SMCA or SMCM lens, please post your experience as it might indicate that this particular flash unit was defective, but I doubt that, as it did give correct exposure with a DA 35mm f2.8 macro, provided the subject were not too close (the flash instructions list a minimum distance), and also gave correct exposure with test shots taken with DA 70mm f2.4 @ 4 feet and both f8 and f16. Also, the flash gave the same unsatisfactory exposures using SMCA lenses on two different Pentax bodies, K5 & K3. I think I've given the flash every chance to work properly with a manual focus macro lens, but it does not. As noted, if manual flash is necessary, I'd rather use my old Sunpak ring flash because it has a wider selection of manual outputs. (1/2; 1/4; 1/8; 1/16), the flash head is smaller and it's a full ring, not two half-rings.

[manntax]

For the last round of tests desrcibed above: 1) the flash was set at "auto" with no exposure compensation; 2) the +/- metering compensation on both cameras was set at zero; 3) the flash output adjustment accessed via the camera's four-way controller was set at zero. Matrix metering was used (during the first round of testing I switched to spot metering twice but it made no visible difference to the exposure obtained immediately before using matrix). I dumped all the files from the two cards used, so I'd have to reassemble the set-up and repeat the test to post any images. I'm loath to do that because the flash has been packed away for a second time to be returned for a refund, and I'd rather not take it out again. AGAIN, I conclude that PTTL WILL NOT FUNCTION with any manual SMCA lens. If anyone has obtained correct PTTL exposure using an AF160 and an SMCA or SMCM lens, please post your experience as it might indicate that this particular flash unit was defective, but I doubt that, as it did give correct exposure with a DA 35mm f2.8 macro, provided the subject were not too close (the flash instructions list a minimum distance), and also gave correct exposure with test shots taken with DA 70mm f2.4 @ 4 feet and both f8 and f16. Also, the flash gave the same unsatisfactory exposures using SMCA lenses on two different Pentax bodies, K5 & K3. I think I've given the flash every chance to work properly with a manual focus macro lens, but it does not. As noted, if manual flash is necessary, I'd rather use my old Sunpak ring flash because it has a wider selection of manual outputs. (1/2; 1/4; 1/8; 1/16), the flash head is smaller and it's a full ring, not two half-rings.

Sorry to hear about your experience. even more that this means that my future upgrade plans are going to wait until Ricoh do something about this issue. My experience with SMC-A 50mm f2.8 macro lens and SMC-F100mm f2.8 macro lens are both the same as yours. Both lenses with flash in AUTO will overexpose badly on my K-01 if I am in macro distances - in normal distances ( 1m + ) lenses would deliver perfectly exposed shots with AF160FC flash set on AUTO. At the same time I repeat again - flash is functioning 100% as expected with my K10D. To my that's at least an indicator that there must be something wrong with firmware on cameras K5 onwards (K-01 is actually a K5 with some changes ).

I am awaiting response from Ricoh to my question about this issue - and I will keep the thread alive.. I should probably update my review too ...

[stevebrot]

I am awaiting response from Ricoh to my question about this issue - and I will keep the thread alive.. I should probably update my review too...

Yes, please update your review!

As for the OP, Ricoh/Pentax is(are) who he should be talking to. Bringing customer service into the loop on a warranty issue is the quickest way to bring the problem to the attention of engineering.


Steve

[Digitalis]

In case of 100mm and 50mm lenses (at 1:1 or 1:2 respectively ) my flash is nearly touching the subject - just 1-2 inches away

That scenario is precisely why I don't use short macro lenses. Ringflash is difficult to control at short distances as 1/16th power isn't low enough. The AF160FC can throttle the power down to 1/64th in auto mode, but the inability to select that power level manually is a source of annoyance for me.

AGAIN, I conclude that PTTL WILL NOT FUNCTION with any manual SMCA lens. If anyone has obtained correct PTTL exposure using an AF160 and an SMCA or SMCM lens, please post your experience as it might indicate that this particular flash unit was defective

P-TTL on my AF160FC ringflash works correctly with M*,K*, A, FA, DFA, lenses on my K10D, K7, K5IIs and 645D.

* SMC-M and K series lenses will not work with P-TTL - you have to use manual power control, and SMC-A lenses will not work with P-TTL unless they are set to the "A" setting on their aperture ring.

[WPRESTO]

That scenario is precisely why I don't use short macro lenses. Ringflash is difficult to control at short distances as 1/16th power isn't low enough. The AF160FC can throttle the power down to 1/64th in auto mode, but the inability to select that power level manually is a source of annoyance for me.



P-TTL on my AF160FC ringflash works correctly with M*,K*, A, FA, DFA, lenses on my K10D, K7, K5IIs and 645D.

* SMC-M and K series lenses will not work with P-TTL - you have to use manual power control, and SMC-A lenses will not work with P-TTL unless they are set to the "A" setting on their aperture ring.

If your 160 works in PTTL with a K5IIs, I would presume it should work with both my K5 and K3, but rest assured, it does NOT.
As I stated, when testing the aperture was set via the camera, so all the SMCA lenses were set at "A" on the aperture ring. The only lenses that I use without setting the aperture ring to "A" are a manual-focus Pentax 85mm "soft" (the diaphragm is manual only) and a Samyang 24mm tilt-shift (pre-set diaphragm). When I'm using one of the short macros (35mm or 50mm) in studio I use manual flash, as it is always possible to run test exposures even with a live subject. Many studio shots are done with several small manual-only flash units with exposure varied either by moving the flash unit or by covering the tube with one of a series of small plastic ND filters originally designed to fit a little Strobonar flash made back probably in the 1970's. The filters are conveniently held in place with a rubber band. I also use plastic diffusers cut from white sheets from art supply that are held by velcro attached to the flash and the sheet such that the latter bows out. For large subjects in studio I use larger flash units in manual mode sometimes with a "beauty dish" reflector attached. A recently purchased Cactus flash is especially useful because the output can be reduced all the way to 1/128. I'm tempted to get a second unit, as it is the most flexible manual-only flash I've encountered, and the wireless triggering with the "V6" unit is very convenient.

[stevebrot]

If your 160 works in PTTL with a K5IIs, I would presume it should work with both my K5 and K3, but rest assured, it does NOT.

It occurred to me yesterday and just now when reading this comment that there might be more than one production variant of the AF-160FC in the mix. The flash has been in production for a few years now and may well have gone through a few changes.


Steve

[Digitalis]

Using this set up:



What you see here is a Pentax K5IIs with an A series 50mm f/1.7 with a FA series 25mm extension tube with the AF160FC ringflash

Subject to flash distance is approximately 6 inches (152mm).



Flash was set to auto mode, camera was in full manual mode.


Pentax K5IIS - Pentax SMCP-A 50mm f/1.7 - 1/180th F/11 ISO 80 -25mm FA series extension tube used- Pentax AF160FC ringflash - in Auto mode.

I left the EXIF information in this image intact.

It occurred to me yesterday and just now when reading this comment that there might be more than one production variant of the AF-160FC in the mix. The flash has been in production for a few years now and may well have gone through a few changes.

Mine is one of the early AF160FC units - made in japan, the serial number on it is in the hundreds.

[stevebrot]

If your 160 works in PTTL with a K5IIs, I would presume it should work with both my K5 and K3, but rest assured, it does NOT.

Can you post a single example photograph, preferably an in-camera JPEG with no PP and all exif intact?


Steve

[Digitalis]

Can you post a single example photograph, preferably an in-camera JPEG with no PP and all exif intact?

Show us exactly what you are attempting to photograph, and how you are trying to do it.