Agfa Isola II - focusing question

<p>Dear Classic-camera-experts, <br>

I have a weak spot for older Agfa cameras and right now a problem with 2 otherwise fine Agfa Isola 2 cameras: the lens tubus (the small one) won't move out when I turn the focusing ring to a closer setting. There's no sign of a changing extension-length (the lens on a Isola I extends just fine). I would be very surprised if there's some kind of internal focusing, so is there maybe an easy fix? I'm not exactly a craftsman, but would give a simple repair-job a try.<br>

I got both cameras for 1 Euro, so a possible loss wouldn't make me cry.<br>

Many thanks in advance, Georg.</p>

<p>Some insight, perhaps ... ?<br>

<a href="http://www.flickr.com/groups/agfaisola/discuss/72157624213302904/">http://www.flickr.com/groups/agfaisola/discuss/72157624213302904/</a><br>

Jim</p>

<p>I had my Isola II close-by so I checked it, if you turn the lens to focus is only moves very little, it doesn't really come out of it's fitting. I know mine I good because I already used it. Open the back and use a groundglass to check if it focuses alright. The Isola II is pretty simple so not much can go wrong with it.</p>

<p>Jim - thanks! <br>

Uncle Goose - thanks a bunch! I owe you one or two.<br>

I did a quick focus-test with a bit of parchment-paper and the little movement of the lens was indeed enough to focus the Agnar.<br>

I will do a field-test tomorrow if the weather cooperates.<br>

I was worried because the lens of my Isola I extends quite a bit (much more than the Agnar from the Isola IIs) when I turn the focus-ring.<br>

Georg</p>

<p>The Isola I seems to have a lens made from a single element or maybe two elements. These simple lenses use "unit focussing", i.e. the whole lens is moved when focussing. <br>

All Agnar lenses I have seen use "front element focussing", i.e. only the front element is moved. (Actually this does not really change the distance between lens and film plane but rather the focal length.) With front element focussing, the displacement of the focussing element is much smaller. (The reason behind using this method is that you need a much shorter focussing thread - since this is a "multiturn" thread it is much cheaper to manufacture a short one.) So possibly you will hardly notice the movement of the lens element, but it is quite effective. </p>

 

<p>The Agnar is actually a simple triplet, it's capable of nice results if you can avoid flare.</p>

<p>Winfried, many thanks for your explanation. <br>

I've run a roll of well-expired HP5plus thru one of the Isola II's and the „„front-cell-focusing" seems to work just fine.<br>

I really suck at guessimating distances, but sharpness-wise the results are not too bad for hastily done handheld snaps. <br>

Expired HP5plus in Rodinal 1:25 was probably not the best choice for this test and I had a lot of trouble to get something out of the negatives.<br>

Here's a picture shot at a distance of about 1.20 Meters:<br>

<img src="http://farm6.staticflickr.com/5112/7373040096_3cdd53c0f4_z.jpg" alt="" width="628" height="640" /><br>

...and here is a (vertical:-) shot focused at infinity:<br>

<img src="http://farm8.staticflickr.com/7073/7187811875_53f9319d40_z.jpg" alt="" width="640" height="629" /></p>

<p>Both pictures were taken with „Agfa Spezial Gelbfilter Nr. 1”, at 1/100sec and f/11.<br>

Thanks for your help, Georg.</p>