300mm DA* problem

**nitehntr** · 08-17-2014, 06:22 PM

this afternoon I was out and tried using my 300 f4 DA* on both a K3 and K5 and it is stuck wide open on f4. it has never done this before. I used 3 other lenses including the 50-135 the 60-250 and an old screw drive tamron 70-200 and all worked flawlessly. has anyone had this problem or does anyone know of a fix without sending it to CRIS ?

I am getting pretty discouraged with these lenses. I have 5 of them and three of them have been to the shop the 16-50 and the 60-250 for SDM replacement and the 300 for not auto focusing and now this.

any help would be appreciated.

derekkite · 08-17-2014, 07:48 PM

Check the lever on the mount end. It should move easily. If it is bent towards the center of the lens it won't catch the mechanism in the body.

**nitehntr** · 10-12-2014, 05:49 PM

it moved just fine. is the aperture controlled mechanically or electronicly i am just mystified.

derekkite · 10-12-2014, 08:34 PM

Mechanically. If you remove the lens and look into the body on the shutter release side there is a lever that moves up and down. The lens should be normally at a small aperture, if it is off the camera it should be a very small hole. You can move the lever with your finger to open the aperture, and it should pop back to the closed position. When you mount the lens it catches on the lever in the body, holding it open for focus and exposure. When you hit the shutter button the lever releases, the spring closes the aperture to whatever you want. If the mechanism is not right, the spring not able to pull it, it won't.

Since it is on both bodies I would think the lens has a problem.

RonHendriks1966 · 10-13-2014, 07:23 AM

Always clean the contacts of the lens so communication is flawless.

**nitehntr** · 10-13-2014, 01:43 PM

Originally posted by derekkite

Mechanically. If you remove the lens and look into the body on the shutter release side there is a lever that moves up and down. The lens should be normally at a small aperture, if it is off the camera it should be a very small hole. You can move the lever with your finger to open the aperture, and it should pop back to the closed position. When you mount the lens it catches on the lever in the body, holding it open for focus and exposure. When you hit the shutter button the lever releases, the spring closes the aperture to whatever you want. If the mechanism is not right, the spring not able to pull it, it won't.

Since it is on both bodies I would think the lens has a problem.

thanks fir your help i hadn't thought to check if the kens was wide open when its off and it is stuck. all my other glass works just fine on both bodies. i am very disappointed in these supposed top of the line lenses. i bought 5 of them over about a 4 year period and three of them have been to the shop the 300 will make it twice each for it and the 60-250 and the 16-50. they were my reward fro getting all my sons raised and through college and as of now i will look for third party used if need be unless something changes pretty drastically.

derekkite · 10-13-2014, 02:03 PM

Originally posted by nitehntr

thanks fir your help i hadn't thought to check if the kens was wide open when its off and it is stuck. all my other glass works just fine on both bodies. i am very disappointed in these supposed top of the line lenses. i bought 5 of them over about a 4 year period and three of them have been to the shop the 300 will make it twice each for it and the 60-250 and the 16-50. they were my reward fro getting all my sons raised and through college and as of now i will look for third party used if need be unless something changes pretty drastically.

I agree. It sucks.

08-17-2014, 06:22 PM	#1
nitehntr Site Supporter Join Date: Jun 2009 Location: Rivesville West Virginia Photos: Gallery Posts: 238	*300mm DA problem** this afternoon I was out and tried using my 300 f4 DA* on both a K3 and K5 and it is stuck wide open on f4. it has never done this before. I used 3 other lenses including the 50-135 the 60-250 and an old screw drive tamron 70-200 and all worked flawlessly. has anyone had this problem or does anyone know of a fix without sending it to CRIS ? I am getting pretty discouraged with these lenses. I have 5 of them and three of them have been to the shop the 16-50 and the 60-250 for SDM replacement and the 300 for not auto focusing and now this. any help would be appreciated.

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08-17-2014, 07:48 PM	#2
derekkite Pentaxian Join Date: Sep 2011 Location: Nelson B.C. Posts: 3,782	Check the lever on the mount end. It should move easily. If it is bent towards the center of the lens it won't catch the mechanism in the body.

10-12-2014, 05:49 PM	#3
nitehntr Site Supporter Join Date: Jun 2009 Location: Rivesville West Virginia Photos: Gallery Posts: 238 Original Poster	it moved just fine. is the aperture controlled mechanically or electronicly i am just mystified.

10-12-2014, 08:34 PM	#4
derekkite Pentaxian Join Date: Sep 2011 Location: Nelson B.C. Posts: 3,782	Mechanically. If you remove the lens and look into the body on the shutter release side there is a lever that moves up and down. The lens should be normally at a small aperture, if it is off the camera it should be a very small hole. You can move the lever with your finger to open the aperture, and it should pop back to the closed position. When you mount the lens it catches on the lever in the body, holding it open for focus and exposure. When you hit the shutter button the lever releases, the spring closes the aperture to whatever you want. If the mechanism is not right, the spring not able to pull it, it won't. Since it is on both bodies I would think the lens has a problem.

10-13-2014, 07:23 AM	#5
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675	Always clean the contacts of the lens so communication is flawless.

10-13-2014, 01:43 PM	#6
nitehntr Site Supporter Join Date: Jun 2009 Location: Rivesville West Virginia Photos: Gallery Posts: 238 Original Poster	Originally posted by derekkite Mechanically. If you remove the lens and look into the body on the shutter release side there is a lever that moves up and down. The lens should be normally at a small aperture, if it is off the camera it should be a very small hole. You can move the lever with your finger to open the aperture, and it should pop back to the closed position. When you mount the lens it catches on the lever in the body, holding it open for focus and exposure. When you hit the shutter button the lever releases, the spring closes the aperture to whatever you want. If the mechanism is not right, the spring not able to pull it, it won't. Since it is on both bodies I would think the lens has a problem. thanks fir your help i hadn't thought to check if the kens was wide open when its off and it is stuck. all my other glass works just fine on both bodies. i am very disappointed in these supposed top of the line lenses. i bought 5 of them over about a 4 year period and three of them have been to the shop the 300 will make it twice each for it and the 60-250 and the 16-50. they were my reward fro getting all my sons raised and through college and as of now i will look for third party used if need be unless something changes pretty drastically.

10-13-2014, 02:03 PM	#7
derekkite Pentaxian Join Date: Sep 2011 Location: Nelson B.C. Posts: 3,782	Originally posted by nitehntr thanks fir your help i hadn't thought to check if the kens was wide open when its off and it is stuck. all my other glass works just fine on both bodies. i am very disappointed in these supposed top of the line lenses. i bought 5 of them over about a 4 year period and three of them have been to the shop the 300 will make it twice each for it and the 60-250 and the 16-50. they were my reward fro getting all my sons raised and through college and as of now i will look for third party used if need be unless something changes pretty drastically. I agree. It sucks.