What has happened to this glass?

morfa · Post by **morfa** » Tue Nov 24, 2009 11:46 am

Received a lens with a rear element looking sort of fuzzy. Any idea what has happened to this lens?

The above was cropped from this view:

Not surprisingly, the contrast delivered by this lens is really bad.

/John

g4lab · Post by **g4lab** » Tue Nov 24, 2009 12:26 pm

Somebody took that element out and tried to repolish it.
There is a phenomenon known to gem facetors as "orange peel" which happens on quartz gems and it looks like this lens has it.

DaveW · Post by **DaveW** » Tue Nov 24, 2009 12:44 pm

Looks like somebody has tried to polish out this long scratch:-

DaveW

morfa · Post by **morfa** » Tue Nov 24, 2009 1:39 pm

yes, "orange peel" is very fitting description of how it looks! It is very even across the entire glass surface, all the way out to the extreme edges so it makes sense the element was removed.

I wonder if they tried to sand blaster it

g4lab · Post by **g4lab** » Tue Nov 24, 2009 6:15 pm

What is the make and age of the lens??

morfa · Post by **morfa** » Wed Nov 25, 2009 12:00 am

It'a a Leitz Milar 50mm f4,5. Not sure when it was made but I'm guessing 30's - 40's?

Cactusdave · Post by **Cactusdave** » Wed Nov 25, 2009 12:47 am

It almost looks 'etched' . Very strange.

augusthouse · Post by **augusthouse** » Wed Nov 25, 2009 1:05 am

I once saw someone do this to an old lense (process Nikkor) intentionally to achieve a special effect; must have been during a moment of inspiration; though others may view such an act differently.

Have you used lense for taking any images; just out of curiosity?

Craig

morfa · Post by **morfa** » Wed Nov 25, 2009 1:34 am

Leitz Milar 50/4.5 converted into an orange peel, special effect lens:

Unconverted Milar 40/4.5

DaveW · Post by **DaveW** » Wed Nov 25, 2009 1:48 am

I don't suppose somebody converted it to a soft focus portrait lens did they? Much cheaper to use Vaseline on a filter though.

Still I suppose a portrait photographer could have tried converting an old lens to produce the effect they desired and used on a day to day basis? It certainly seems to have produced a not unpleasant soft focus effect.

Perhaps, as I thought earlier, the element got scratched so they thought nothing to loose if they abraded it further?

DaveW

ChrisR · Post by **ChrisR** » Wed Nov 25, 2009 2:04 am

No chance it's a coating of some sort I suppose?
Presumably you'll send it back - otherwise not much to lose with toluene, acetone, methylene chloride...

augusthouse · Post by **augusthouse** » Wed Nov 25, 2009 3:26 am

Minor adjustments applied (Auto Contrast in CS4) to the orange peel version.
(hope you don't mind John?)

Craig

ChrisR · Post by **ChrisR** » Wed Nov 25, 2009 4:49 am

AN interesting excercise in Photoshop to try to improve the fruity version.

I never use Levels, I find you can always do the same and more with Curves. Having done that, Smart Sharpen seems to work best. Straight USM makes the highlights ugly, which can be controlled in SS.

After all that's done, there's a vast improvement, but the image from the clear lens is still better.

It's a pity the two pics aren't exactly the same section of, er, whatever it is. It's a good subject - what IS it??!

morfa · Post by **morfa** » Wed Nov 25, 2009 6:26 am

Thanks Craig, you are right, most of the contrast and sharpness issues can be corrected in post processing so I wouldn't call this lens worthless. Unfortunately the image in the viewfinder is also affected which makes the lens more difficult to use. Also, when I'm out in the field it's essential to me to get relevant feedback by looking at the results on the LCD. If the lens is low contrast to begin with it's difficult to tell if there is anything else compromising the image quality (stray light hitting the front element etc.)

ChrisR> It's the side of a match box. You know where you strike fire to the matches. Not sure what the English word for it is. Sorry about the misalignment – quick and dirty handheld shots.

Harold Gough · Post by **Harold Gough** » Wed Nov 25, 2009 7:46 am

morfa wrote: It's the side of a match box. You know where you strike fire to the matches. Not sure what the English word for it is.

It's called the "striker". Not many people know that!

Harold