Hasselblad meter knob cover

[paulcooklin1]

<p>Hi - On my metering knob there's a white ridged platic 'cover', or at least it looks like the cover to protect the selinium cell. However, Im unable to slide it across. I can see a groove which Im assuming its meant to slide on.<br>

My question is: is that the cover, does it even have a cover and how do I engage it.<br>

Thanks!</p>

[q.g._de_bakker]

<p>Paul,</p>

<p>It's a diffusor, turning the meter into an incident light meter.<br>

To slide it in front of the cell, you have to push the little metal pin you'll see at one end of the diffusor up (or down, depending on which way you are looking at it), to release the lock.</p>

[ken_wayne1]

<p>You have to slide the little button...see attached photo. If you did this then there may be another problem.</p>

[paulcooklin1]

<p>Thanks to the both of you...I did did see that and tried it but its not budging...will try again.<br>

No pic?</p>

[ken_wayne1]

<p>Computer bonkered out on me. See if you can see this pic.</p><div></div>

[paulcooklin1]

<p>Ken - yep, thats what Ive been pushing/sliding...no joy.<br>

Thanks.</p>

[paulcooklin1]

<p>...one thing, there's a small screw to the top left, should this be loosened?</p>

[q.g._de_bakker]

<p>No.<br>

I'm not quite sure which one you mean, but no.</p>

<p>If the diffusor refuses to budge, the best thing to do is to take the meter apart and see what is blocking the thing. Else, the only option is to use force, which never ends well...<br>

But taking it apart (through the bottom) is a risky business too.</p>

[mark_farrell]

<p>Sometimes the correct interpretation of directions on how to do something may be clear to writer, but not necessarily the reader. This may or may not be instance here, but I'll give a try.....</p>

<p>In Ken's image above the little button has a slight gap just above it. The button should be able to be pushed/slid towards the outer part of the knob into this gap easily and the button is spring loaded so it should also return to the position as shown in the image. When the button is pushed in the direction of the gap it lifts a locking pin from a notch in the channel where the diffuser slides which allows the diffuser to slide.<br>

<strong>Simultaneously</strong> while pushing the button sideways towards the gap, attempt to slide the diffuser into either the open or closed position. Unless something has gotten into the channel where the diffuser slides, the diffuser should move quite freely. </p>

[al_bowers]

<p>Paul,<br>

You had asked about the small screw on the knurled part of the meter knob. This small screw allows you to set a small bias in the zero of the meter itself. If you cover the selenium cell, the needle will fall to a "zero" position. You will note the mirror under the needle allows you to make a very accurate assessment of the needle position (this is necessary for some light levels, as can be seen by the width of the black/white stripes to the EV numbers). After letting the needle fall to the extinction level, you can adjust that small screw to precisely line up with the zero mark. Your meter is now set.<br>

The meters were make by Gossen, and I have found my meter knob to be very accurate over the years.<br>

Best regards,<br>

Al Bowers</p>

[al_bowers]

<p>Paul,<br>

More info:<br>

http://www.hasselbladhistorical.eu/PDF/HasManuals/KnobMeter.pdf<br>

Regards,<br>

Al Bowers</p>

[paulcooklin1]

<p>Thank you Al, I believe Im doing the right thing by trying to slide the button to one side, but it's not moving.</p>

[q.g._de_bakker]

You are, Paul.<br><br>But the thing won't budge, even when you move the catch? And you can't see anything obstructing it?<br>Then it's time to open the thing and fix it.<br>Not too hard, and <a href="http://home.tiscali.nl/qnu/PN/Meter%20knob.pdf">here's</a> a page from the service manual showing how it comes apart and goes together again.<br>(the 3 54011/3 first, then lift the top cover and remove SFS-2x6. Mind that you don't lose spring 54011/5. And be very careful about the extremely thin leads and the needle of the ampere meter.)

[paulcooklin1]

<p>Thank you, Q.G. I'll have a go at that later.</p>

[paulcooklin1]

<p>Fixed!<br>

I took it apart and found that the cover was upside down which meant of course it was back to front too. By that I mean instead of the catch being nearest the sensor it was at the other end and therefore the release mechanism wasn't able to 'release'.<br>

At least I think I now have it the correct way. It works which is the main thing although I might take the spring out altogether.<br>

Many thanks to all who replied!!</p>