Why a mottled image on gg?

[tonyowen]

As promised, a digital shot that shows the difference - more of a light loss than mottling - digital shots taken within minutes of each other, same view than ps onto same canvas NO OTHER changes

regards
Tony
Attachment 182663

[Cor]

First guess: if the 180mm is the sharpest image you can get: lens cells of the 180 mm are messed up perhaps.... You could try this: in relatively dark room: point the lens (in your hands) to a window, have a light wall behind you, try to project an image by moving from and away of the wall (around 180mm..;-)..), and try to judge if you can project a sharp image..

good luck,

Cor

[tonyowen]

First guess: if the 180mm is the sharpest image you can get: lens cells of the 180 mm are messed up perhaps.... You could try this: in relatively dark room: point the lens (in your hands) to a window, have a light wall behind you, try to project an image by moving from and away of the wall (around 180mm..;-)..), and try to judge if you can project a sharp image..good luck, Cor

Did that, eyesight judgement 'projected images' okay. However, see another digital image that shows the gg view of the 180mm lens with and without the rear element.
Have noticed a few 'specks' on the exterior of both 'outwards' lens faces [ie not internal faces] of the rear element that wipe off quite well.

As before, any suggestions/ideas/comments welcome
regards

Tony
Attachment 182671

[Tin Can]

I have found many fine looking GG to be actually filthy dirty on the ground side.

I now take them out and wash both sides with dish soap.

Be careful of the lines or grids as they can be damaged.

[tonyowen]

I have found many fine looking GG to be actually filthy dirty on the ground side.I now take them out and wash both sides with dish soap.
Be careful of the lines or grids as they can be damaged.

Good thinking, I did this many months ago, perhaps it is time to do it again - the red lines seemed to be very tough.

regards
Tony