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01-01-2020, 04:29 PM   #1
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K-7 Problem With inputting focal length.

After cleaning the sensor in my K-7, I installed my SMC Pentax-FA 1:4.5~5.6 80~320mm on to the body and was shown options of 300mm or 350mm. I chose 300mm being

closest to the actual of 320mm. I took many shots at variable focal lengths and the EXIF data shows 300mm for every shot. Please help.

Thnx,

Tony

01-01-2020, 04:37 PM   #2
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On an FA lens you should not have to input the focal length unless for some reason you are shooting in manual and using the aperture ring, and I'm not sure there is a setting for 320. But when you set it manually it stays at that length until changed or turned off.

Last edited by ramseybuckeye; 01-01-2020 at 05:01 PM.
01-01-2020, 05:30 PM   #3
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If the camera is asking for a focal length on an FA lens then either:
1) The lens has the aperture ring in something other than the 'A' position
2) The lens contacts need cleaned.

Suggest you check the aperture ring and make sure it is in the 'A' position first. If it is then try cleaning the contacts.

I do not believe there is a 320mm selection in the camera for focal length, but unless you are shooting with the lens in manual you should not have to set it anyway, the camera will read it from the lens.
01-01-2020, 07:28 PM   #4
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Well now, it appears as though I may have opened up a can of worms with this issue, as I have discovered a problem with the K-7, however I will have to post that in another thread.

I went ahead as suggested and cleaned the contacts in both the camera and the lens. Went through every line item in the Menu, just to make sure I did not personally throw a monkey wrench into

the works. With the aperture ring in the "A" Position, I mounted the lens back onto the k-7 body and the camera asked me for a focal length. I had no choice other than 300mm and then took a few

shots, checked the EXIF data and sure enough, Focal Length showed up as 300mm. The auto-focus functioned great up to 160mm and then quit. At that point I had to use the shutter speed and ISO settings in order to produce a decent image.

I just recalled that I had the same exact problem with a Pentax-M 40~80mm Macro lens and I did not know which number to enter, 40mm or 80mm? So whatever I entered, that is what appeared in the EXIF data, and again, that is a Pentax-M lens.

I will mention briefly the other issue I discovered with the K-7. When I attempt to change shutter modes, I noticed that when I enter AV and then attempt to change to TV, it stays in AV Mode according to the read out on the back panel. The only setting that changes properly is M for Manual Mode. I wonder if these two issues are related. I will go ahead and post this latest discovery in the proper thread section heading. Thanks for the info. Am I confused? Aaaaaahhhh, Yup.! I wonder if the lenses are too old for the k-7. Tonytee.


Last edited by Tonytee; 01-01-2020 at 07:30 PM. Reason: Grammar Correction.
01-01-2020, 08:01 PM   #5
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QuoteOriginally posted by Tonytee Quote
W
I just recalled that I had the same exact problem with a Pentax-M 40~80mm Macro lens and I did not know which number to enter, 40mm or 80mm? So whatever I entered, that is what appeared in the EXIF data, and again, that is a Pentax-M lens. Tonytee.
Whatever you put in on a zoom like that will stay until changed or turned off. They recommend that you would input 40 if shooting at 40, 55 if shooting at 55, etc. It's totally manual.
01-01-2020, 08:43 PM   #6
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Do you have any other "A" lenses (A, F, FA, DFA, DA) lenses you can test this with? M lenses do not have contacts so using this will not isolate whether the problem is with the camera or the 80-320mm lens.
01-01-2020, 09:17 PM   #7
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QuoteOriginally posted by Not a Number Quote
Do you have any other "A" lenses (A, F, FA, DFA, DA) lenses you can test this with? M lenses do not have contacts so using this will not isolate whether the problem is with the camera or the 80-320mm lens.

Yes, I do have the SMC Takumar F 70~200mm lens with the A aperture. With the lens mounted and the camera turned on, there is no request for focal length.

Thank you very much.

TT

---------- Post added 01-01-20 at 09:22 PM ----------

QuoteOriginally posted by ramseybuckeye Quote
Whatever you put in on a zoom like that will stay until changed or turned off. They recommend that you would input 40 if shooting at 40, 55 if shooting at 55, etc. It's totally manual.

I understand what you are saying in regards to the 40~80, but should the same apply to the 80~320mm? So every time I change focal lengths, I must go into the program

and change it accordingly? Geeezzzz, what a hassle. My senses tell me that the 80~320mm may soon be headed for the donation bin at Goodwill.


Thank you very much for the info as it is very helpful.


TT
01-01-2020, 09:26 PM   #8
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And to correct myself a manual focus "A" lens will require you to enter in a focal length to. I should have said "Do you any other autofocus lenses".

BTW - does the 80-320mm show "F--" in the viewfinder even when set to "A"? This might indicate an electrical fault with the "A" contact. Another possibility is that the "feeler" contact in the lens barrel the senses the focal length are bent/broken/dirty.

01-01-2020, 09:33 PM   #9
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QuoteOriginally posted by Not a Number Quote
And to correct myself a manual focus "A" lens will require you to enter in a focal length to. I should have said "Do you any other autofocus lenses".

BTW - does the 80-320mm show "F--" in the viewfinder even when set to "A"? This might indicate an electrical fault with the "A" contact. Another possibility is that the "feeler" contact in the lens barrel the senses the focal length are bent/broken/dirty.


Yessir, it does in fact reveal the "F--" in viewfinder when set to "A". My immediate thought was that the camera was not recognizing the lens, or possibly, vice versa.

Well, I thank you very much.

TT
01-01-2020, 09:39 PM   #10
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Tony, could you take a picture of the lens mount on the 80-320 and post it?
01-01-2020, 09:55 PM   #11
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The FA 80-320 lens, especially the black version for some reason, does have something of a reputation for communication/ electronic issues. I'd echo Not a Number's advice and try with different AF lenses to determine if the fault is with the lens or camera.
01-02-2020, 03:14 AM   #12
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photo of bottom of Pentax-M 80~320mm 1:4~5.6 Lens

QuoteOriginally posted by bertwert Quote
Tony, could you take a picture of the lens mount on the 80-320 and post it?

Photo of the rear of Pentax-M 80~320mm Lens. Thanks for viewing.
TT

---------- Post added 01-02-20 at 03:14 AM ----------

QuoteOriginally posted by bertwert Quote
Tony, could you take a picture of the lens mount on the 80-320 and post it?
It is done sir.

Thnx,

TT
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01-02-2020, 05:31 PM   #13
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Tony, as far as I can work out, the lens mount and contacts looks in good condition, have you tried cleaning them?
Also double (or triple) check that the aperture ring is definitely set to the A position.
01-02-2020, 09:37 PM   #14
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I did do all that you mentioned. I concur with Suzhouren, that this version lens has a reputation for communication issues with cameras. It does generate some really nice images so I will hold on

to it for a while yet and see what develops. As with most long telephotos, it is soft at 300mm, but easily correctable in PPE. Thanks very much for your assistance.

TT
01-03-2020, 01:32 PM   #15
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The notorious 80-320

I had this one too. And when I started using it on a Samsung GX10 (the sibling of the K10D) it behaved like a manual aperture lens. It got worse to the point that I could not get it in the "A" position anymore. During the first pictures I took I had to manually set the lens for the SR. And the aperture stayed in 32 position when I had the aperture ring set to A. After putting it back on the film era camera I had the same problem there. I send it to Pentax to repair and they returned it with the comment it was not worth reparing it anymore. In the end the pictures where either over- or underexposed. As the problem became bigger and bigger I binned it.

Last edited by Unregistered User; 01-03-2020 at 01:38 PM. Reason: some mistakes.
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