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08-13-2010, 05:29 PM   #1
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Help with Lens Problem

I will try and explain exactly what happened as best as I can. I am sorry if it is a little bit vague or anything that might not have the easiest meaning.

I have only had my Kx for about a month and wanted to go a little bit further with my focal length then the kit lens was providing, so rather then splurging on a brand new lens I bought an old Vivitar 70-300mm from a friend. Upon shipping it he informed me there was a ricoh pin in it so I quickly found out how to remove it and upon receiving it did so, before attaching it to my camera.

The problem was somewhere during my removal of the pin i seemed to have messed up the aperture ring. It had an A setting so I attached it followed the instructions for manual lenses completely. My camera is not adjusting the aperture as it should on the A setting though. I can easily move to a different stop on the lens and everything works fine but A setting is non existent.

If there is anyone who has experience with this lens that may be able to offer an explanation as to what I may have done I would appriciate it. If i screwed it to the point of non repair it sucks, but as the lens is still functional it isnt a total loss but buying a perfectly good lens and messing it up still bothers me a bit, I would like to figure out what it could be.

If there is something I missed that may help further explain I'll try and answer all questions as best I can.

08-13-2010, 07:31 PM   #2
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I'm confused as to what you meant when you say it has an A setting and yet you followed the instructions for using manual lenses. If it has an A setting, you shouldn't *need* to follow the instructions for manual lenses, as it is not in fact a manual lens (at least, not as far as exposure is concerned). So what exactly are you doing, what are you expecting to see happen, and what is happening instead?
08-13-2010, 07:43 PM   #3
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If the camera is recognizing it as an "A" type lens (when its aperture ring is set to A), something like F4.0 will appear in your viewfinder. Do you see this?

If so, the camera thinks it is an A type lens; check it out & let us know - we'll go on from there.
08-13-2010, 07:53 PM   #4
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QuoteOriginally posted by Marc Sabatella Quote
I'm confused as to what you meant when you say it has an A setting and yet you followed the instructions for using manual lenses. If it has an A setting, you shouldn't *need* to follow the instructions for manual lenses, as it is not in fact a manual lens (at least, not as far as exposure is concerned). So what exactly are you doing, what are you expecting to see happen, and what is happening instead?
A as in the A on the aperture ring indicating the lens allows for the camera to determine aperture. Manual meaning manual focus. If i set the aperture to a high aperture and snap the picture the camera is not adjusting as it should with the aperture ring set to A.

And yes the camera with the lens set to "A" shows f4.5 on the display. If I move it to an actual aperture setting then I get the F--


Last edited by AutoEccentric; 08-13-2010 at 07:59 PM.
08-13-2010, 07:59 PM   #5
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I think if you are getting an aperture read out with the ring set to "A", it should be fine.

Just remember changing the aperture in modes other than Aperture Priority, you need to hold the "+/- AV" bottom as you roll the jog dial.

If its just the aperture readout, if you switch the lens aperture ring off "A" position, the camera will show "F--". It is like this for all electronic lenses on Pentax dSLRs. (I think this is just a matter of their mount design, noting to worry about)
08-14-2010, 10:55 AM   #6
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QuoteOriginally posted by AutoEccentric Quote
A as in the A on the aperture ring indicating the lens allows for the camera to determine aperture. Manual meaning manual focus. If i set the aperture to a high aperture and snap the picture the camera is not adjusting as it should with the aperture ring set to A.
OK, but that's still not clear. What exposure mode are you in (eg, M, Av, P, etc)? What isn't adjusting - the shutter speed or the aperture? What evidence do you have that this is happening? Step back and explain *exactly* what you are doing and *exactly* what you are seeing.
08-14-2010, 05:47 PM   #7
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QuoteOriginally posted by Marc Sabatella Quote
OK, but that's still not clear. What exposure mode are you in (eg, M, Av, P, etc)? What isn't adjusting - the shutter speed or the aperture? What evidence do you have that this is happening? Step back and explain *exactly* what you are doing and *exactly* what you are seeing.
It is hard for me to explain *exactly* as I am new to this and am not 100% sure on all the info you may need as I mentioned in my original post.

I always shoot in Manuel mode.

The evidence I have that the aperture is not opening would be extremely dark pictures even with a wide open aperture like f/4.5. Since the aperture stays the same that is all I see is dark images. Once I change the setting off of the "A" and move it to one of the manual stops, everything works fine.

Beyond what I have just said I don't know what else to say, again if I am missing some vital piece of information that may help diagnose the problem I apologize.
08-14-2010, 06:35 PM - 1 Like   #8
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With the lens Removed from the camera, looking at the mount, 2 things should happen when you set the lens to A. You should see the contact on the rear of the lens moving in and out (going from A to non-A). When you are in the A setting, the aperture blades should be closed and you should be able to open and close them with the lever on the lens. When you take the lens off of A, you should see the aperture blades move with each different setting of the aperture ring and you should be able to move them with the lever. Is all that happening?

When you put the lens on the camera, and set the lens to A, you should see the Aperture you choose on the viewfinder display (and/or the rear screen) just as you would your kit lens. With the lens mounted on the camera, regardless of setting, the aperture should be open (on any K mount lens). Set your camera in the custom menu for Optical Preview. When you pull the power lever all the way to the right, you should see the lens stop down to your chosen aperture (in M mode). This should be true again, regardless of lens type. At this point the only thing that should be different is How you set the aperture, either with the ring or the camera.

You said that if you take the lens off of A, everything works fine and that is the confusing part. The only thing that should change is how YOU set the aperture. The mechanical function of the camera controlling the lens should be the same whether in A (on the lens) or not. You say that on the lens A setting, your camera recognizes that you have an A lens (shows f4.5). What happens when you change aperture with the camera (it will cycle through the settings on the screen/viewfinder)?

If the lens is behaving (mechanically) as it should, the only thing I can think of is that you've broken or missed some electrical contact and the camera does not know Where to Stop closing the aperture down. The result is, it is just closing the aperture all the way down (f22 or whatever the smallest is) by default, resulting in your dark photos.




Last edited by JeffJS; 08-14-2010 at 06:40 PM.
08-14-2010, 07:02 PM   #9
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Jeff, thanks for the detailed reply on what should be happening. I really am not sure what it is I did, or if it is just me not setting everything correctly on the camera. When I took the pin out and saw that the aperture was not acting how I had expected I may have just pictured the worst case scenario.

When I put the lens on, it is by default at the smallest aperture. This is troublesome because unless I am looking directly into light I can hardly see anything.
08-14-2010, 07:10 PM   #10
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I think you may have removed the aperture actuation lever instead of (or in addition) to the Ricoh pin.
08-14-2010, 07:21 PM   #11
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QuoteOriginally posted by AutoEccentric Quote
Jeff, thanks for the detailed reply on what should be happening. I really am not sure what it is I did, or if it is just me not setting everything correctly on the camera. When I took the pin out and saw that the aperture was not acting how I had expected I may have just pictured the worst case scenario.

When I put the lens on, it is by default at the smallest aperture. This is troublesome because unless I am looking directly into light I can hardly see anything.
QuoteOriginally posted by Mike Cash Quote
I think you may have removed the aperture actuation lever instead of (or in addition) to the Ricoh pin.
Either that or it was modified before it was purchased at some point. I have to agree that the camera is not controlling anything.

If it can be reliably used when not in A (which is still somewhat confusing), then you have a nice fully manual lens to play with.

Good luck..
08-14-2010, 07:28 PM   #12
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Well the original owner who is also a member of these forums seemed to have no problem with it on A before so I can only imagine it is something I did, when removing the pin. Either way your right, It still works in manual aperture which is fine, I have an AF 70-300mm on its way in the next week.
08-14-2010, 07:37 PM   #13
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If it had a Ricoh pin, then it won't have an A on the aperture ring, it'll have a P.

If it has an A on the aperture ring, it's not a Ricoh lens and you removed something else.

Ricoh data contacts don't line up with Pentax data contacts on the flange, and a Pentax camera won't recognize a Ricoh lens.
08-14-2010, 08:02 PM   #14
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QuoteOriginally posted by alohadave Quote
If it had a Ricoh pin, then it won't have an A on the aperture ring, it'll have a P.

If it has an A on the aperture ring, it's not a Ricoh lens and you removed something else.

Ricoh data contacts don't line up with Pentax data contacts on the flange, and a Pentax camera won't recognize a Ricoh lens.

Well that may explain it, if that is the case. After I was told that it had a Ricoh Pin I did some research as far as what to look for in case it did. There was definitely a pin sticking out. It also had the Markings PK-A/R which was very similiar to the other lenses which had Ricoh Pins. I put two and two together and took it out.
08-14-2010, 08:38 PM   #15
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You removed the aperture actuation lever, which in how the camera controls the aperture blades. The clue was when you said you look through the lens and see blackness.....the camera mount interacts with that lever to hold the blades open until the time of shooting. (Also, an aperture doesn't open up to shoot....it closes down).

If at all possible, reinstall the lever. Then whether the A position works or not you can at least use it as an M lens and manage to see through the lens before shooting. Without the lever you're going to have the functional equivalent of an old preset lens, where you'll have to focus, then stop down the aperture with the ring (and darken the viewfinder), meter manually, then shoot.

Get one of your other lenses and play around with the lever to see what function it serves. Then take a look inside the camera mount (lens off) and fire the shutter. You'll be able to see the part that interacts with the lever. A little hands-on exploring will soon make it apparent to you what the piece does and why you really ought to reinstall it. You'll see that with the lever gone expecting the camera to be able to control the aperture is like chopping off your legs and expecting to be able to wiggle your toes.

Last edited by Mike Cash; 08-14-2010 at 08:44 PM.
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