Lens - 'moderately dusty' inside - should I buy?
Posted 22 March 2007 - 01:36 PM
The majority of my lenses are pretty clear from dust (particularly the inside of them.) So I'm not sure what to expect from a lens that is 'moderately dusty' inside. As the incoming light intercepts the various particles of dust, would there be much of a degrading effect? Any loss of sharpness or detail? Or would it only mean that there would be an increased chance of flare? In short, would the item be worth bidding on if all the other aspects of the equipment sound in good order? By the way, according to the seller, there is no fungus, haze or scratches with that lens.
There are only a few hours left in the auction.
Posted 22 March 2007 - 02:12 PM
light should hit it and stop right there - so its just a slight T-stop reduction, nothing really ... maybe a little diffraction around the edges actually
Any haze, oil, fungus or otherwise translucent material will unfortunately scatter the light and make it incoherent when it reaches the film. Barely noticeable in most cases until that critical shot ...
With eBay you never know - I personally respect the sellers potential honesty, which is a plus, but then maybe he/she has cottoned onto that factor - "Admit one flaw, and the rest will go unnoticed" - eBay really brings out the shittiness in some people and somewhat less often the greatness in them ...
Always a gamble.
Posted 23 March 2007 - 11:37 AM
Posted 23 March 2007 - 12:29 PM
I agree with your Angenieux tech. But since most zoom lens rear groups are a self contained, (seperate housing) set of optics, there is little chanch of dust getting inside. Just keep the last element clean the way you would the front one. Speaking of front elements, I would not worry to much about that either unless it is a very short focal length which can be subceptible to flare from scratches. More so the smaller the stop that is used.
Some or my presonal 35mm still lenses were on the border of being filthy inside (like some car mechanics the last thing I wanted to do after servicing lenses all day was to work on my own) and I never was bothered by it in my prints. So Patrick, since the lens you are talking about is not a wide angle I would not be to concerned about the dust. Also since lenses of this focal length tend to be of simple (fewer elements) design, I don't think it would be to exspensive to have a CLA done to it. 75mm is not such a common focal length I would be interested in hearing about what brand it is.
Edited by chuck colburn, 23 March 2007 - 12:30 PM.
Posted 26 March 2007 - 08:41 AM