How important is keeping the front element clean?

[JohnTF]

Oh: and thank'ee for the "good appetite" -- I've just finished a light lunch of oeuf brik with a kir on the side. It must have been your good wishes that made it taste so good!

Cheers,

R.

I would hope Kir Royal made with the widow Clicquot? You put a brick on your egg? ;-)

Have heard the T Shirt thing before, normally qualified by using very well worn and washed many times/ ready to be discarded, T Shirt, though with the cost of Microfibre very low, I see little economic advantage, however, some times one uses what is at hand.

Alcohols can be tricky on old lenses-- and people tend to confuse rubbing alcohol, which can easily be 30% water, with other things added for the skin- with the 100% isopropyl I have only seen in labs, and sold to clean microscope lenses and labeled as such. I don't trust the labels though, but our microscopes were so abused by students it did not seem the prime concern. We also had the administrative idiots who dumped the older B&L scopes @ $10.00 each to replace them with terrible China made units.

If you work with students, you will spend a lot of time cleaning microscopes, they often ignore instruction and fail to understand the term parfocal ending up with the high power lens dipped in what ever fluids/ stains, used on slides, or breaking the cover slips. Goes with the territory.

I have seen camera tech guys who are artists at cleaning lenses, who work very quickly, with what ever seems to be the perfect solvent for the task always at hand.

IMO, all vintage lenses should be cleaned with extreme caution, the new coatings are terrific. Some dusts can scratch anything up to diamond.

One of my TAs was demonstrating to the class how a knife blade was softer than the saphire crystal on his watch, but forgot he had sharpened the knife with a diamond bearing device-- expensive point learned. Keep all diamond encrusted knife sharpening devices away from camera glsss. -- OK, does that cover it? You may never know what is in the dust.

BTW, do you know the Mohs hardness of modern coatings? Probably relatively high?

Stop teasing us with your lunch, we know you have unlimited access to the good stuff and can say good appetite in 20 languages-- and you can send me that Spanish cured ham -- Christmas is coming-- will swap Rodinal for Margeaux.

Regards, John-- you should be preparing dinner by now?

 

[Frontman]

Microfiber is a fairly recent invention, and it wasn't long ago when there were fewer choices.

In the Army I often had to clean the scope on my rifle. It was equipped with a Hensoldt scope which probably cost as much as the Army paid me in 6 months. I used rags made from military issue t-shirts which I had worn out. The Army did not skimp on the quality of clothing, and the cotton used in thes shirts was especially fine. I also made shoe polishing rags from these t-shirts, you could get a mirror shine, no other cloth worked better.

I have a couple/few (actually many) old Rolleiflex cameras, some have quite badly scratched lenses, but I can't pick out the shots which were made by the scratched lenses from the shots which were made with the clean lenses.

 

[peterm1]

A few rules of thumb. Marks on the front lens have less impact than marks on rear lenses. For the most part they have little or no effect in practice. But marks on front lens have most effect when the sun is in the frame (or near to.) In this situation it might have an impact. Worst of all is haze inside the lens. This seems to really screw up pictures in my experience. If you do get a really serious mark on the front lens (i.e. a deep scratch or gouge) then the old trick is to use some black paint or something of this sort to fill it in. Looks ugly but stops abberant light from that scratch creating a flare point in the image. Effectively it restores IQ. Obviously does not work with lots of scratches.

PS in relation to microfibre, I love it. I use it to clean my lenses and I use it to wrap and store my lenses and cameras. Greta stuff.

 

[paradoxbox]

the front element can be smudged, damaged, scratched all to hell and it won't make much of a difference. the only thing that changes is when light hits the element at oblique angles - it may cause a contrast loss or a flare in certain cases. if that's a worry put a hood on it and the problem goes away.

here's my rolleiflex 2.8 xenotar's taking lens. note the dozens of deep scratches in the front element, probably from being hit by a zipper or something similar.

but it still takes fine photos. this one with ilford 3200.