Which way does a cemented doublet face?

[shalom_septimus]

<p>I have here a shutter from a Blair Hawk-Eye #3. (Long story shut, I'm trying to compile a collection of at least one camera in each roll film size Kodak made. This one was pretty well worn out, but it fills that vacant #103 spot and was cheap. Strangely enough, the shutter worked once it got loosened up.)<br /><br />This particular shutter had the lower-cost option of a cemented doublet lens in the back threads, with a blank in the front threads. I unscrewed the ring holding the glass in, and it fell out on the table. Unfortunately I didn't notice which way it was in to begin with. (Got it started turning accidentally when trying to rinse some grime off the lens with a bit of cheap vodka, and unscrewed it the rest of the way to see what would happen. Yeah, I know.)<br /><br />So: Can anyone tell me whether the concave or the convex face should be facing the film plane? So far I've tried assembling it both ways, and neither way looks right.</p>

[colin carron]

<p>I don't have a Blair Hawkeye but have looked at three different box cameras where a simple lens is mounted behind the shutter. In all of them the concave face is toward the front (toward the shutter).<br>

Maybe someone has more specific information for the Blair Hawkeye.</p>

[dave_g1]

<p>If the lens is behind the aperture, the concave side will face forward.</p>

[shalom_septimus]

<p>Thanks. I reassembled it that way and put the thing back together.</p>

<p>That shutter is now in a different camera, though, a Folding Pocket Kodak #3. Almost looks like it belongs there, except for the Blair nameplate on the speed control.</p>