oil on iris blades?

[marcel_bourgeoisie]

I rather foolishly just purchased a lens on ebay and the aperture

ring is sticking. I was told that it could be oil on the iris blades

but I can't afford to get it fixed or get it open with one of those

cheap mini screwdrivers. It's a 28 mm NikKor for an FE2, it does

work if you "work" it a little and of course it works at f2.8 but

there's nothing more annoying than pressing the depth of field

preview and watching the lens darken over a period of a few seconds

while it snaps into place. Does anyone have any ideas-disappointing

buy of the year.

[kelly_flanigan1]

Ben; did the 28mm F2.8 Ai work ok when first purchased from the Ebay seller; or was it bad from the start? <BR><BR>I have purchased several old Nikkors off of Ebay; and not had a problem yet.<BR><BR>The sticking diaphram is a serious problem for an auto diaphram camera; like the F series. The diaphram may lag on one exposure; and not another. Lagging diaphram problems also can be subtle; they show up with motor drive shots as a exposure variation.<BR><BR>Does the Ebay seller do repairs? Maybe you could split the repair cost. It sounds like the grease went bad in the helcoid area; and got on the diaphram.<BR><BR>One can still take photos be pressing ghe stop down; then the shutter; after the diaphrame closes...this is a PITA....

[Robert_Lai]

Don't try to open it up yourself. My brother tried this on a Canon 58mm f/1.2 FL lens (against my advice), and the first thing that happened was a whole bunch of little ball bearings and springs fell out. Once they're gone, they're gone!. Then, if you get the helical off without marking the position in which the parts were originally aligned, then there are several different possibilities for which helical alignment is correct. Only ONE of them will lead to correct infinity focus. This is, of course considering that you don't scratch the glass with your screwdrivers in the process. This is definitely not an amateur repair job.<p>The best route is to try and get your money back from the original seller. If the seller described the lens as being in perfect working condition, then get a refund from the seller. If it was one of those "AS IS" type auctions (and this should have been a warning to start with), then you may be out of luck. If you can't get your money back, then my next suggestion is to ask a repair shop how much it will cost to fix, or sell it again with an accurate description. Either way, you'll be out of money.

[marcel_bourgeoisie]

Thanks for the response, the lens wasn't working when it came but in a frenzy of excitement I gave the seller a good review before really checking it out. He offered to split the cost after a number of

e-mails but nothing came. It was my own fault really but that doesn't make it any easier to swallow.

 

Fixation said they could do it for £50 and it should still end up being cheaper than buying the lens from Jessops et al so I'll get saving (student!)

 

Thanks again.

[kelly_flanigan1]

Ben; dont feel to bad about buying a dud...It does happen at times to all of us....I have my share of goofups...BUT it that is the way I have learned to check out stuff! <BR><BR>Repairing it yourself is possible; but their is the risk of goffing it up too! I have bought many junkers to fix; sometimes one needs special tools; or a spring will zip out and head towards France.....In the old days we would sketch how stuff came apart...Today a small digital camera works well for recording of "which part goes where".......<BR><br>You might try several differnt repair shops in the UK; the repair rates may vary abit..........Sometimes with non-photographic optical repairs I do; I will do it for 2/3'rds to 1/2 the normal rate; if I have 1 month! ie it is filler work when there is slack time!...

[todd peach seattle, washi]

If you get the urge to have a go at it yourself, you might try checking in with this mailing list:<br>

<a href="http://groups.yahoo.com/group/NikonRepair">http://groups.yahoo.com/group/NikonRepair</a>

<p>

Having precisely the 'right' screwdrivers makes a big difference. I bought myself a good set of Wihas and they have paid for themselves several times over in repairs that I have managed myself.

[david_h._hartman]

Many older Nikkors have there bayonet screws locked with a white paint like substance. This can be softened with MEK applied with a Q-Tip swab. YMMV. If you apply more force you may torque the head off a screw.

 

Usually you don�t open a Nikkor lens for cleaning from the back anyway. The elements, front, aperture assembly and rear come out as a group from the front. You may or may not need a spanner wrench. You unscrew the front and rear groups intact from the aperture assembly and spray and blow out the aperture assembly several times with an alcohol based electronics cleaner. Then clean the iris blades with acetone again using a Q-Tip. YMMV. After you are finished the lens needs to be collimated. If you don�t have the equipment to collimate a lens you can use a 6x finder on an F2, 3, 4 or 5 and a light pole that�s a 1/4 to 3/8 mile away. It may take several tries as some lenses creep as you tighten them.

 

Concerning the seller. They many have unloaded a bad lens on you or the problem may have occurred in shipping. Over-heating of a lens is a common cause of this problem. The oil in the grease separates at high temperature such as those found in a car or truck that is parked in the sun and runs or migrates to the aperture blades. The problem might show up quickly or take weeks or months.

 

It�s a bread and butter job for camera repair shops and due to the economy they need bread and butter just now. Sorry this happened but the lens is not toast. It�s probably better to have a shop do the job. Some people can do some of their own repairs and some can�t. Camera repair folk put their pants on one leg at a time just like the rest of us. So far I�m never butchered a lens but I came close on my first try.

 

Hope this helps,