Some visible stain-like markings on lens.

[ndrockstar]

Hi guys!

I got this problem and can't seemed to find any articles regarding it on the Internet.

I borrowed a 50mm prime from a friend to try on during my last getaway trip. And found out that there is this circular stain-like marking right in the centre of the lens when it fogged. Found out by accident when I didn't realize the air conditioned room was much much lower than the temperature outside causing the lens to fog noticeably.

I don't know if its a stain or not in the 1st place, but there is this clear circular mark which had a different degree of vapor formed on the lens when I breathed on the lens. However, the lens looked perfectly fine with the naked eye when the vapor evaporated off.

Owner of the lens didnt know what was it. I'd check with a friend and he says the lens is at the initial tags of molding. Seemed like some coating issue to me but it doesn't seemed as bad as those stated on the websites.

Would like to hear if anybody experienced such problems with their lens and if there r any solutions to rectify this.

Pretty pleases and thanks for kind responses

 

[esoeij]

It would help if you could post a photo of what you have described.

 

[lawrencewkl]

Hi,

have you tried cleaning the lens surface? It might be a very light oil stain from touching it.

 

[ndrockstar]

It's a shame I didn't manage to get a picture of it when I had the chance. I'll try to get my friend snap a picture of it to post it up here. It could be an oil stain come to think of it. Pls wait up for the picture and thanks guys!

 

[ndrockstar]

Hey guys! The stain kind of like mystically disappeared according to my friend. No cleaning done and she just left it inside dry box. Lol
But I swear it was around during the days I was using it! arrgh... Thanks anyways. And if anybody knows what it was, please let me know...

 

[catchlights]

these marks are common on lenses, it only shows up when the surface is wet, but generally has no effects on the images quality.

 

[ndrockstar]

Yep! Noticed that it doesn't affect the images. Jus a tad sad that it could be the result of my handling. As I wasn't sure how common such things were till now. Thanks for the info!