[grimnicholas]

I'll attach some photos, it's being sold AS IS with "fog"
I'm curious if it will affect IQ and if it is something that will get worse, or is fixable?
For interest it's a 60-300 Tamron Zoom, highly regarded lens so it would be cool to know it's not a lost cause

Thanks all!

Attached Images

   

[GUB]

Short answer haze is bad.
Finger print = Bad - PentaxForums.com
And if it is rainbow colored then it likely would spread further.
If that is the haze around the edges then once you stop down a couple of stops it should be fine. But is that what you want from your lens.

[grimnicholas]

Short answer haze is bad.
Finger print = Bad - PentaxForums.com
And if it is rainbow colored then it likely would spread further.
If that is the haze around the edges then once you stop down a couple of stops it should be fine. But is that what you want from your lens.

An interesting read, i'm even more curious about the (now dead) link that was pointing to cleaning the lens too much being bad!
I will ask the seller about the haze and if it's the whole crescent in that photo.
Generally, if it means stopping down and it won't be an easy thing to fix, maybe a pass on the lens is a better choice.
Tough to know, especially as a lot of older lenses aren't in the best condition being that they're getting quite old... hmmmmm....

[kypfer]

In a best case scenario the "haze" will cause a loss of contrast which may be recoverable "on the computer", and maybe the loss of fine detail which once it's gone is gone!
The symptoms will be worse in a backlit scenario and will probably also be noticeable if there are any bright highlights in the image.
Haze and similar symptoms are conditions which won't "go away" and will very often get worse.
"Fog" on the front or rear element will often "hide" similar symptoms deeper in the lens … you'll not know 'till you start to strip it for cleaning.
Unless the lens was being virtually given away, or I was offered a full refund option, including p&p, I'd pass.

[grimnicholas]

In a best case scenario the "haze" will cause a loss of contrast which may be recoverable "on the computer", and maybe the loss of fine detail which once it's gone is gone!
The symptoms will be worse in a backlit scenario and will probably also be noticeable if there are any bright highlights in the image.
Haze and similar symptoms are conditions which won't "go away" and will very often get worse.
"Fog" on the front or rear element will often "hide" similar symptoms deeper in the lens … you'll not know 'till you start to strip it for cleaning.
Unless the lens was being virtually given away, or I was offered a full refund option, including p&p, I'd pass.

Sage advice, thanks. Will give this one a pass & keep in mind for the future that haze is actually quite a problem!
Seems so innocuous the way it's described as a little fog on the lens 🥴

[PJ1]

I have had only one lens with haze that was worth mentioning. It was a CZJ 180/f2.8 (a Zebra version). I removed the front retaining ring and lifted out the objective lens. All the haze was on the back of that element. A quick clean and reassemble and the lens was as good as new. It remains so. Other situations might not be so simple but it is worth a look.

[pepperberry farm]

probably not - you're buying someone else's problem, while hoping that it doesn't become your problem....

[grimnicholas]

probably not - you're buying someone else's problem, while hoping that it doesn't become your problem....

I tend to do that, I must learn some patience instead of thinking - eh, it's flawed but i will fix!