Diphragm problem

[emmanuel_b1]

<p>I have a Contax AX.<br>

In Av mode , I don't have the same result between what I put on the ring of the lens and what is shown inside the viewfinder:<br>

50mm 1.4 MM shows 1.2 when it is 1.4<br />35mm 2.8 AE is Ok <br />50mm 1.7 MM shows 2 when it is 1.7<br>

The good value is the one which is put on the ring or the one which is shown in the view finder?<br>

Does it matter ?<br>

Anyone with the same issue?<br>

In P mode minimum shown is 1.4 for 50mm 1.4 and 1.7 for 50mm 1.7 , it looks good.</p>

[JDMvW]

<p>As an autofocus camera this should be on some other forum. I expect the moderator will move it.</p>

[emmanuel_b1]

<p>Contax AX should be a classic camera...except it has a special autofocus system on it.<br>

It is more a "manual body with an autofocus system" than an autofocus camera.<br>

Unfortunately , there is no Contax manufacturer section.<br>

I posted several times here without any moderator shout.</p>

 

[q.g._de_bakker]

<p>I agree.<br>

The AX did something in a very innovative way. And that thing happens to be autofocus.<br>

Now nobody followed suit. But still...</p>

[JDMvW]

<p>No problem, if Q.G. is happy, who am I to demur?<br /> As you know, I'm willing to stretch 'manual' (and according to QG, 'classic') considerably.</p>

<p>Seems to be another case for making this forum something like "Swell old cameras" or SOC ;)</p>

[q.g._de_bakker]

<p>Hey, "manual" was only added back then because it would define what the topic of this thread should be once the "classic" idea was scrapped.<br>

So it became "manual", and a cut-off date was added.<br>

A testament to the fact that this forum has very little to do with real classic cameras.<br>

Any old junk...<br>

Nice to see that a true classic comes along now and again. Sad that it is then jumped on because it doesn't satisfy the strict definition of any old junk. <br>

;-) </p>

[JDMvW]

<p>You're always so subtle and polite, Q.C.</p>

<p>"Jumped on"? I just suggested that it didn't technically fit this forum. That's all.</p>

<p> </p>

[mfophotos]

<p>I've said it before, there should be an "Orphaned Cameras" forum ... that would take care of a few brands.</p>

[JDMvW]

<p>Poor Emmanuel.</p>

<p>I wish I had the answer to your question. I wasn't trying to derail your question, but I did wonder where it would fit and find an answer.</p>

[sumo_kun]

<p>OK, back to the question. The finder should show the correct value in any mode as far as I know. The lens may be the problem. The camera gets the aperture info from the lens and if the ring on the lens is mis-calibrated or the mechanism worn, then it will give false info to the camera. Try mounting the problem lens and then setting it on max aperture in Av mode. Then give the aperture ring a gentle twist back and forth. If the aperture reading changes then there is slop in the lens.<br>

If it does not change and the camera reads the correct value when one stop down from max, then the small tolerance between the max aperture of the lens and camera coupling mech is probably off. Most probably the lens is to blame. You should check the problem lenses on another body to see if the same thing happens.</p>