View Full Version : lense imperfections

Ronald J LaMarsh
11-Feb-1998, 01:06
I need some opinions on how much effect things like cleaning marks etc have on i mage quality. I use 4x5 and enlarge to 11x14 and shoot almost all B&W. The clean ing marks I'm talking about are on the rear element and can only be seen with a 7x loupe while pointing the lense directly at a quartz halogen lamp about 6in aw ay. I know that any kind of scratch or other imperfection will have an effect on con trast but does anyone know or have an opinion as to how much? I recall reading s omething written by Ansel himself stating that even a visible scratch on the rea r element would probably not have much of an effect unless struck by direct brig ht light! I am of the opinion that such minor imperfections have more of an effect on valu e than actual image quality as long as you're not enlarging a 4x5 to 5ftx7ft. An y other opinions? Also has anyone ever heard of or read anything about computar symmatrigons?

Peter Hughes
19-Feb-1998, 00:05
For what you describe, I doubt those marks will be a problem for you. I have a 1 0" WF Ektar with moderate polishing marks on the *front* element. The only time I notice it on the photograph is when I am shooting directly into very bright li ght, such as sunlight reflected on water.

Joseph Alsko
15-Mar-1998, 13:44
This is horrible!. How can you be expected to produce fine images with such hor rendous cleaning marks on your lens? Please send this monster to me immediately and I will make sure it receives a proper burial.... right inside my camera pac k. Please be sure to also include a Zone VI 8x10 lensboard with it. As far as computar symmatrigons are concerned - I think a good virus program wil l be able to eliminate them from your computar.

Sergio Ortega
30-Mar-1998, 14:16
Lens imperfections can be a very tricky thing.

Whenever you're BUYING a used lens, particular from a New York dealer, any and all imperfections, short of a cracked or missing element, are totally insignific ant. "Trust me, this will NEVER show in your negatives!"

Whenever you're SELLING a used lens to one of these guys, any flaw, even a spec k of dust on the UV filter protecting the front element, will seriously degrade the image and make it almost impossible to re-sell. "Would I lie to you?"