Hello Help team, I've recently rediscovered my love for B&W film photography and managed to score a load of second-hand darkroom gear for a really great price, so I built myself a darkroom in the garage. I've spent a good chunk of the last few months locked away developing loads of film and many great prints (to my eye, anyway). The only problem I had was that I was unable to print any of the photos I have taken on my old Agfa Synchrobox, which takes 120 film. To my great delight, last week I spotted an old Meopta Opemus 5 enlarger with a colour head in one of my local op shops, going for a bargain price (still in its original case an everything)! Only thing is, there are a couple of problems with the enlarger... First, as the light source is a 100W 12V halogen globe, it needs a transformer to run. It did not come with the transformer, but I was able to get a 105W 12V downlight transformer from my local electrical supplies shop. That seems to have worked OK, and the globe is glowing strongly, however, the light coming out of the lens seems a bit dull, and is decidedly dark around the edges. I took apart everything that I could and gave all of the glass and lenses a good clean, but it hasn't made any noticeable difference. I also went out and purchased a new globe to see if that would help, but no luck. I wonder if anyone out there might know what's causing the darkness around the edges of the image? There is one part within the colour head that could be the culprit... A spherical part that the light source gets reflected into horizontally, which then reflects the light 45 degrees to vertical... but I can't figure out how to get it open to attempt to clean it. Any help will be greatly appreciated!