View Full Version : Dust in a G Claron

7-Mar-2007, 12:31
Please I need some help.

I couple of months ago I bought a G Claron 355 in barrel . Now looking at the lens in transversal way I see like dust into the front cell.
I asked to the seller if it is possible to clean the lens but he replay that to disassemble the lens is worse that to have the dust because it is necessary to use a “collimator” and for do this it is necessary to send the lens to the factory in Germany (I’m in Italy) .

May question is : haw serious is the presence of same dust into the lens? It is right that the clinging of the lens is so difficult ?

Thanks and sorry for the English


7-Mar-2007, 12:40
Bonjourno Giorgio,

Welcome to the forum...

A little dust creates absolutely NO problems whatsoever... just shoot with it and enjoy the pictures from it. It's a great lens. :)

A couple of my lenses have a bit of dust in them too....


7-Mar-2007, 13:07
well Now i'm better


7-Mar-2007, 13:14
I have my favourite lenses with dust and debris inside.

Once has black dots, scratches, and dust. It produces fine photo's. Don't worry about the little bit of dust.

The worst thing is that opening the lens may let MORE dust in!

Brian Ellis
7-Mar-2007, 18:38
If you shine a flashlight through one end of a lens, even a brand new one, while looking through the other end you might be appalled by all the dust in there. Lenses aren't made in clean rooms so there's plenty of opportunity for dust to collect inside during the manufacturing process.

7-Mar-2007, 21:20
With all the care they take in making lenses, all the expensive equipment and precise calculations, the intricate designs and testing....you'd think they'd be a bit more meticulous about that. Sure, it's going to affect image quality so very little...but isn't it also a matter of pride in the product? If I ordered the 550 XXL for $5000+ I'd be pretty irate with a spec of dust between the sealed elements.

(In fact for 5K it should come with a person to dust the outside too...)


Jan Pedersen
8-Mar-2007, 07:45
On the subject of taking a G-Claron appart for cleaning, does anyone know what the best tool is to remove the front cell? Know it would be possible to fabricate something but if readily available i would like to buy one. My 210 needs a cleaning.

Robert Hughes
9-Mar-2007, 13:36
As for dust in a lens, it reminds me of a conversation I had with an old photo geezer who was a bombardier over Europe in WW2. He told me about filming through the bay of his B-17 with a beat-up Eyemo newsreel camera; his lenses were so fogged, dirty and grease spattered he could hardly see through them, but the pictures came out fine all the same. What's a little flare to a 500 lb bomb?

Kevin Crisp
9-Mar-2007, 14:07
If the Steve Grimes lens wrench is still in production, that is excellent for taking the retainers off the front and rear cells. Use the flat blades and angle them appropriately. The wrench doesn't wobble like some out there. Be very careful of any shims that might be inside, and note which way they are located. I would not take one apart for dust. A really bad case of haze, yes.

Jan Pedersen
9-Mar-2007, 18:11
Thanks for the info Kevin, mine has a little haze around the edges but no dust. Perhaps better to leave as is since it will be out of the light path stopped down a little.

Gene McCluney
9-Mar-2007, 18:52
Please I need some help.

I asked to the seller if it is possible to clean the lens but he replay that to disassemble the lens is worse that to have the dust because it is necessary to use a “collimator” and for do this it is necessary to send the lens to the factory in Germany (I’m in Italy) .


I think that statement is rubbish. I have cleaned many lenses in my collection, and while I don't have a G-Claron, they can't be any different. Here is my opinion: Most lenses for large format are built into "cells" One cell on either side of the iris diaphram. These cells unscrew from the barrel. One can clean both sides of each cell with no danger of disturbing optical centering, as the centering is machined into the cells and barrel. If you screw them fully into the barrel, they will be just as they left the factory. Now, some cells have air-spaced elements within a single cell. These too, can be disassembled with a few simple tools and cleaned. The machining of the lens mount, and any gaskets used determines the collimation. If everything is put back carefully as originally found, collimation will be as the factory designed the lens. I clean lens elements, and as I am replacing them I blow compressed air across them to keep dust out. A little dust inside is just fine, a haze or film is another matter and really should be cleaned to achieve best contrast. I cannot think of a lens that has "adjustable collimation" within a lens cell. All adjustment is done with the machining of the cell and a washer or ring. These are fixed elements and cannot be changed, unless the lens is re-assembled wrong. The "centering" of the elements is done when the outside diameter of each glass element is ground down to final size at the factory. As stated, this is my opinion, but I think a lot of people will agree with me.