Is my enlarger lens dodgy?

[Rhianan]

Hi,

I just picked up a load of darkroom equipment yesterday for my first foray into developing prints at home.

I seem to have an iffy lens on my paterson colour enlarger. When I turn the enlarger on, the light from the lens is very bright in the centre and then fades out rapidly, there is a square-ish pattern to the shadow, its hard to explain. I have unscrewed the lens and the shadow disappears and the light is bright and even on the base board.

this leads me to believe that there is a lens problem, am I right? should i buy a new lens. what would you suggest? I am developing b&w 35mm.

thanks
rhiannan
xx

 

[Neal]

Dear Rhiannan,

Good news! The enlarger light source is designed to evenly light a negative (or slide). You need to put a negative in and focus on that. It is unlikely that the lens is not usable.

Neal Wydra

 

[srs5694]

Just out of curiosity, what model enlarger do you have? I've got a Philips PCS130, which was also sold under the Paterson label. If this is what you've got, there's a Yahoo group devoted to it. It's got low message volume, but is helpful.

As to your question, it's hard to be sure. If your lens has a defect or other problem that would cause uneven illumination, though, chances are it'd be visible if you look through the lens -- say, something lodged inside the lens. So I recommend you take a look. If you see nothing obvious, try making some prints. If they're significantly lighter around the edges than they should be, then I'd first recommend that you open the enlarger and look for problems outside the lens -- dirt, spider webs, etc. If you see nothing wrong with the enlarger, then consider buying a new lens.

Fortunately for you, used enlarger lenses are selling for peanuts on eBay, so getting a replacement shouldn't cost a lot. There are a lot of threads here on APUG discussing the merits of different brands and models. The quick and dirty conclusion: Get a 6-element lens from a major manufacturer (Nikon, Schneider, and Rodenstock are most often mentioned, but Fuji and several others also make excellent lenses). The lower-quality 3- and 4-element lenses can be good, but they aren't quite as good as 6-element models in good condition, and the price difference is very small today. Unfortunately, you need model-specific knowledge to spot the 6-element lenses. Some manufacturers use the "-on" suffix for 6-element lenses and "-ar" for 4-element lenses, but this convention isn't universal.

 

[Lee L]

If you've got the Paterson version of the PCS-130, you also need to be sure you've got the right condensers for the focal length of the lens. The condensers are behind a panel on the front of the enlarger, between the filter drawer and the negative carrier. It may not be readily apparent to you that the panel comes off. If you post the exact enlarger model and lens focal length, we can help you with the right info for the condensers.

Lee

 

[Jim Jones]

Lee's advice applies to many enlargers. Let us know the enlarger size and model, and the information on the lens, and maybe we can help more.

 

[Rhianan]

Hi,

Thanks for the responses.

I cant find a model number on the enlarger, but I got a book in the kit refering to a Paterson 35 Colour Enlarger. From the pictures the look almost identical, except there a bit between the filter-box-thing and the neg carrier that is missing on mine.:rolleyes: I guess this is the diffuser?

When i put a neg in the image is still weak at the edges and very bright in the middle, and when I print the image is faint at the edges.

I am thinking I need a new lens, I have been looking on ebay and got my eye on a couple. I am now worried about the missing diffuser part if this is what it is....

Of to ebay to look for one.

Thanks again
Love
Rhiannan
xx

 

[srs5694]

I did a Web search and turned up this eBay auction for a Paterson 35 enlarger. If this is what you've got it's definitely not closely related to my Philips PCS130, so I can only give you general advice. From the photo, it looks like a condenser model, so Lee's and Jim's advice about the condensers does still apply. I'm not entirely sure what part you believe may be missing. If it is, as you suspect, the condenser, that's a much more likely source of your problem than the lens, so don't rush out and buy a new lens just yet. A missing or incorrect condenser is likely to cause uneven illumination, just as you describe. (A condenser is like a big lens, but rather than focus light it spreads it evenly across the negative.) With any luck, somebody with the same model you've got can help you out with specifics. Alternatively, perhaps you could post a photo and highlight the part you think might be missing.

 

[Lee L]

The enlarger in the ebay auction is a condenser enlarger, not a diffusion enlarger. The condenser is shown in the middle right photo, the item with the circular orange frame around it. If something like this is missing on your enlarger, that could easily be the cause of your problems.

I did a google search for paterson 35 colour enlarger and found at least three models with that name, although one added "Paragon" in the name. Another source indicated that there were both condenser and diffusion versions of the Paterson Colour Enlarger.

Any way you can post a photo? You might find an image that matches your model with a google image search.

Lee

 

[Rhianan]

thanks guys,

i will post a photo tomorrow.

i'm pretty sure it a diffuser enlarger not a condenser. not so sure there is anything missing now that i have a close look.

i've done google image searches and cant find anything that looks remotely similar to mine.... maybe i have a special paterson one off and its worth a fortune?!?!

i'll post that pic tomorrow.

cheers

x