Decentered lens's - Printable Version
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Decentered lens's - toni-a - 05-17-2016
In the reviews I see decentered lenses as faulty lenses with poor quality. Recently I discovered that this is not totally true.
I was at the repairs and was seeing how decentering is repaired:
The lens used to be mounted on a custom mount and project a chart on a wall now they just shoot a chart using live view plus HDMI projection on a screen, behind the camera mount there are a lot of screws that change position to lens elements, after adjustments any lens is back working nicely.
The bad news in Canon land this is available for all L lenses, but not all L lenses. The guy also told me centering quality is not lifelong after heavy use any lens can acquire such a defect, it is easily repaired. So having a centering defect on my 17-55 IS after ten years of use, isn't surprising.
If you have a decentetered lens this is not the end of the world especially if it is Canon L.
I know now the basics of the trick however I am not ready to do it and I prefer leaving to professionals.
Decentered lens's - davidmanze - 05-18-2016
the biggest cure for de-centered lenses is ebay!
Decentered lens's - Klaus - 05-18-2016
Quote:In the reviews I see decentered lenses as faulty lenses with poor quality. Recently I discovered that this is not totally true.
Some professionals are known to exchange their lenses after a while for that reason.
The real problem started with AF lenses because the focus group has to be "lose". IS made it (much) worse.
However, some lenses cannot be recentered because they are simply not designed to be serviceable and more often than not a recentering attempt yields in sub-optimal results.
Point is also that proper recentering takes time and nobody is willing to pay that.
Decentered lens's - goran h - 05-18-2016
It is more exciting to buy lenses today - a sophisticated lottery.
Decentered lens's - Guest - 05-18-2016
There is some very expensive equipment that will reduce the labor cost to center lenses. I forget where I read about but the traditional way of using a chart and iterating the adjustment is expensive (due to high labor cost). This method used light through the lens of some sort and allow the adjuster to simply turn the screws until things were aligned. Unfortunately the 'light through the lens' was not so simple hence the high expense for the equipment.
Decentered lens's - toni-a - 05-18-2016
Yes exactly the light through the lens is rather outdated with live view and HDMI screen projection you don't need anymore, it still takes time and labor but you get mint condition lens out of a decentered one.
And no I wouldn't sell defective equipment without notifying it is not ethical. EBay is not a cure for decentered lenses.
As for lenses that can't be adjusted usually their price used is lower than the repair process cost... So why bother? Would you repair for 50$ a decentered yongnuo ?
Decentered lens's - davidmanze - 05-20-2016
"And no I wouldn't sell defective equipment without notifying it is not ethical. EBay is not a cure for de-centered lenses".
Unfortunately others are not like you, and it is a cure for a lot of sellers!......that's why I don't buy from ebay any longer, i bought a Sigma 18-50mm F2.8 which was poorly centered and had to pack out the bayonet to make it reasonable. I did risk buying Pentacon 135mm bokeh monster from ebay, knowing that a lens of that era rarely had those problems, it was OK.
I stick to fixed focals these days, out of the six AF-D series 20mm/24mm/28mm/35mm/50mm/85mm F1.8/ 55mm micro all except one copy of the 35mm F2 were well centered, it was only slight but I bought another copy! (all from "Le bon Coin site here in France)