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bruceinvolcan · 01-17-2013, 03:39 PM

Does anybody know why I always get a perfect exposure with the K5 built-in flash and the DA 55-300mm lens but with any of several Pentax A manual exposure lenses it always overexposes? Without the flash the manual focus Pentax A lenses are correctly exposed. Does this mean I need a firmware update or is it that the camera does not receive the information it needs from the lenses with the A setting. I know the TTL flash doesn't work with lenses without the A setting but I thought that it is suppose to work with the A lenses.

SOldBear · 01-17-2013, 03:54 PM

Is the lens' aperture ring set at A? If not, it behaves as an M lens.

bruceinvolcan · 01-17-2013, 05:37 PM

Yes the aperture is set to the A position with the camera in the automatic mode. It meters just fine without using the flash. I have a Pentax A 50mm f1.7 and also several Vivitar lenses with the A setting. It is the same with all of them. They overexpose with the flash but meter just fine without the flash. In the automatic (green) mode the camera won't fire if the lens is not set to the A position.

bruceinvolcan · 01-21-2013, 02:33 PM

I've been playing around some more with the K5 flash. With the Tamron adaptall 90mm macro F2.5 (52bb) and the PK A adapter set to the A setting the camera consistently overexposes or in other words the TTL flash feature doesn't work ( it always fires at full power). I also have a Nikon D7000 and an Ai N adapter so I tryed the Tamron 52bb on the Nikon. The Nikon flash makes a perfect exposure with the same 52bb lens even at close range. Since I have about 4 adaptall lenses if I want to use flash I will have to put them on the Nikon. The K5 flash won't work with my MF Pentax A 50mm f1.7 either but of course I can't put that lens on the Nikon. It seems that the K5 flash will only work with AF lenses. I don't know if I am right but it seems that only the AF lenses are able to convey the correct information that the K5 body needs for the TTL flash. I have an older Pentax mount 28-200mm Tamron with AF and the flash works okay with it as well as with the DA 55-300mm. You can set the K5 on automatic mode and all the A lenses will meter correctly but I can't get any of them to work with the flash. With manual focus lenses on the D7000 you set the aperture wherever you wish and the TTL flash adjusts the output to take the correct exposure. The only thing you can do with the K5 and manual focus lenses is to set the mode on manual and then adjust the ISO and aperture so the picture is exposed correctly with the flash at full power but that is not quite satisfactory. To me it is just better to only use the K5 flash with AF lenses.

toooldtocare · 01-27-2013, 07:47 PM

I just tried my 50mm 1.4 KA lens at f16, 11 and 5.6 and 1.4. Distance was less than two feet and it exposed perfectly? Camera was set to both M and AV in an almost dark room. In M my shutter speed was 1/100, in AV it set to 180 as soon as I opened the flash.

Wayne

bruceinvolcan · 01-27-2013, 10:38 PM

Thanks for your input. Either something is wrong with my K5 or not all the A lenses work the same. Also I have noticed with my K5 that the colors are not processed the same depending on the mode that is used. On the automatic mode the colors appear normal, however in any of the other modes the photos have too much yellow and not enough of green.

toooldtocare · 01-28-2013, 08:11 AM

I have several KA lenses, the 50mm mentioned plus, a 28mm f2.8, 50mm 2.8 macro, 70 - 210 zoom, 28 - 80 zoom, and they all work correctly. I suspect your camera is either defective. One question, do you see the f-stop displayed on the top display? If it does show the f-stop than I think the flash circuit is defective. If you do not see the f-stop, than the lens/camera communication is defective.

Wayne

01-17-2013, 03:39 PM	#1
bruceinvolcan New Member Join Date: Dec 2012 Photos: Albums Posts: 13	K5 flash Does anybody know why I always get a perfect exposure with the K5 built-in flash and the DA 55-300mm lens but with any of several Pentax A manual exposure lenses it always overexposes? Without the flash the manual focus Pentax A lenses are correctly exposed. Does this mean I need a firmware update or is it that the camera does not receive the information it needs from the lenses with the A setting. I know the TTL flash doesn't work with lenses without the A setting but I thought that it is suppose to work with the A lenses.

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01-17-2013, 03:54 PM	#2
SOldBear Veteran Member Join Date: Feb 2009 Location: Alameda, CA Posts: 3,206	Is the lens' aperture ring set at A? If not, it behaves as an M lens.

01-17-2013, 05:37 PM	#3
bruceinvolcan New Member Join Date: Dec 2012 Photos: Albums Posts: 13 Original Poster	Yes the aperture is set to the A position with the camera in the automatic mode. It meters just fine without using the flash. I have a Pentax A 50mm f1.7 and also several Vivitar lenses with the A setting. It is the same with all of them. They overexpose with the flash but meter just fine without the flash. In the automatic (green) mode the camera won't fire if the lens is not set to the A position.

01-21-2013, 02:33 PM	#4
bruceinvolcan New Member Join Date: Dec 2012 Photos: Albums Posts: 13 Original Poster	I've been playing around some more with the K5 flash. With the Tamron adaptall 90mm macro F2.5 (52bb) and the PK A adapter set to the A setting the camera consistently overexposes or in other words the TTL flash feature doesn't work ( it always fires at full power). I also have a Nikon D7000 and an Ai N adapter so I tryed the Tamron 52bb on the Nikon. The Nikon flash makes a perfect exposure with the same 52bb lens even at close range. Since I have about 4 adaptall lenses if I want to use flash I will have to put them on the Nikon. The K5 flash won't work with my MF Pentax A 50mm f1.7 either but of course I can't put that lens on the Nikon. It seems that the K5 flash will only work with AF lenses. I don't know if I am right but it seems that only the AF lenses are able to convey the correct information that the K5 body needs for the TTL flash. I have an older Pentax mount 28-200mm Tamron with AF and the flash works okay with it as well as with the DA 55-300mm. You can set the K5 on automatic mode and all the A lenses will meter correctly but I can't get any of them to work with the flash. With manual focus lenses on the D7000 you set the aperture wherever you wish and the TTL flash adjusts the output to take the correct exposure. The only thing you can do with the K5 and manual focus lenses is to set the mode on manual and then adjust the ISO and aperture so the picture is exposed correctly with the flash at full power but that is not quite satisfactory. To me it is just better to only use the K5 flash with AF lenses.

01-27-2013, 07:47 PM	#5
toooldtocare Senior Member Join Date: Apr 2011 Location: Lake Saint Louis Posts: 126	I just tried my 50mm 1.4 KA lens at f16, 11 and 5.6 and 1.4. Distance was less than two feet and it exposed perfectly? Camera was set to both M and AV in an almost dark room. In M my shutter speed was 1/100, in AV it set to 180 as soon as I opened the flash. Wayne

01-27-2013, 10:38 PM	#6
bruceinvolcan New Member Join Date: Dec 2012 Photos: Albums Posts: 13 Original Poster	Thanks for your input. Either something is wrong with my K5 or not all the A lenses work the same. Also I have noticed with my K5 that the colors are not processed the same depending on the mode that is used. On the automatic mode the colors appear normal, however in any of the other modes the photos have too much yellow and not enough of green.

01-28-2013, 08:11 AM	#7
toooldtocare Senior Member Join Date: Apr 2011 Location: Lake Saint Louis Posts: 126	I have several KA lenses, the 50mm mentioned plus, a 28mm f2.8, 50mm 2.8 macro, 70 - 210 zoom, 28 - 80 zoom, and they all work correctly. I suspect your camera is either defective. One question, do you see the f-stop displayed on the top display? If it does show the f-stop than I think the flash circuit is defective. If you do not see the f-stop, than the lens/camera communication is defective. Wayne