Shoddy Sekor lens

Jarvman · Oct 26, 2007

I've just bought a secondhand 65mm Sekor off eBay for my mamiya c330s. I though all was well with it until last night, it's very clean and the glass is bright. I noticed the front element of the taking lens has got a bit of give in it though. It's able to rattle back and forth although only by a very minimal distance. Will this have a big impact on the images I'm taking. I'm a bit worried now because I've already left positive feedback.

panastasia · Oct 26, 2007

Jarvman said:
I've just bought a secondhand 65mm Sekor off eBay for my mamiya c330s. I though all was well with it until last night, it's very clean and the glass is bright. I noticed the front element of the taking lens has got a bit of give in it though. It's able to rattle back and forth although only by a very minimal distance. Will this have a big impact on the images I'm taking. I'm a bit worried now because I've already left positive feedback.

Probably not. Slight lateral movement should have no impact, IMO.

David H. Bebbington · Oct 26, 2007

Jarvman said:
I've just bought a secondhand 65mm Sekor off eBay for my mamiya c330s. I though all was well with it until last night, it's very clean and the glass is bright. I noticed the front element of the taking lens has got a bit of give in it though. It's able to rattle back and forth although only by a very minimal distance. Will this have a big impact on the images I'm taking. I'm a bit worried now because I've already left positive feedback.

At the risk of stating the obvious, if something''s rattling, it's loose (it could have loosened on its way to you). If (and only if) you have the right tool (a slot-ring key), you could tighten it yourself, otherwise have a repairman do it, as improvized tools inevitably slip and gouge the lens surface. Even a slightly loose lens component will not be correctly spaced and will affect sharpness a little, the main point of course is that if it's a little loose, there's not much to stop it loosening a lot more!

Regards,

David

Jarvman · Oct 26, 2007

What exaclty is a slot ring key and how much do you roughly think it'd cost to repair?

David H. Bebbington · Oct 26, 2007

This is a cheap one. which I don't particularly recommend, but it shows you what one looks like:
http://www.filmtools.com/lenandfilspa.html

Better one:
Dead Link Removed

Regards,

David

Greg_E · Oct 26, 2007

What exactly is the difference between those two tools? I have one of the japanese clone versions, and there are indeed things that I do not like. But it was much less than that Kalt, and looks to be identical.

If I was to make it better, I would put locking screws on the lower rod too. Or fix one end of each rod to provide a better support.

You can find these tools all over Ebay shipped directly from Japan, but I found that after shipping the price was the same as buying from a company here in the USA. (search "camera tools" on ebay) also check here Dead Link Removed

I suggest a set of these wrenches, you need one with a wide flat tip, one with a narrow flat tip, and one with a pointed tip. Having straight sides can sometimes be good, but you could reverse the tips that point in to make them point out, which will then get you deep inside a lens barrel.

Having made repairs with improvised tools, there is nothing like having the "correct" tool to make this less stressful.

John Koehrer · Oct 26, 2007

Just use the edge of a rubber stopper pressed against the ring. The friction between the stopper and the ring will get it tight enough for government work.

David R Munson · Oct 26, 2007

FWIW in a pinch you can also use two mechanical pencils with metal tips as a pin spanner for lens retaining rings. Not the best, but it does work. Also, two jeweler's screwdrivers.

David H. Bebbington · Oct 27, 2007

Greg_E said:
What exactly is the difference between those two tools? I have one of the japanese clone versions, and there are indeed things that I do not like. But it was much less than that Kalt, and looks to be identical.

...

Having made repairs with improvised tools, there is nothing like having the "correct" tool to make this less stressful.

The feature of this tool is that a very small portion of the extremities of the arms is subject to very heavy stress - very poor metal may well fracture under these conditions, even somewhat better metal will wear quickly to the point where the tool tips slip out of the slots and gouges the lens, causing damage much more costly than buying a pro-quality tool in the first place.

Jarvman · Oct 27, 2007

I'm fed up of this camera already. Hopefully the seller will take the lens back seeing as they have a return policy. I've already relisted the c330s on eBay if anyone is interested haha. I never realised you're unable to change the lenses mid roll with a TLR which is no good at all. I'm looking at a modular 6x6 SLR now. A seller on eBay accepted my reckless drunken offer of £190 for a RZ PRO with viewfinder at 2 in the morning. Is that a good price? My entry into 6x6 isn't going well at all.

Ian Tindale · Oct 27, 2007

* You don't need tools to tighten or untighten the 65mm front lens cells. They just unscrew by hand. You could take it all the way off, have a look inside and blow out any dust that might've found its way in there in the meantime, then screw it back on to finger tightness (don't overtighten it, just tight enough to stay where it is).

* Of course you can change lenses in mid-roll - but you have to rack the focus back in to the camera for the interlock to disengage to allow you to unlock the lens pack to change lenses (then switch the dial on the side to 'unlock').

Ian Tindale · Oct 27, 2007

Greg_E said:
You can find these tools all over Ebay shipped directly from Japan, but I found that after shipping the price was the same as buying from a company here in the USA. (search "camera tools" on ebay) also check here Dead Link Removed

Surely buying from Japan or buying from USA both involve similar postage and packing costs?

Jarvman · Oct 27, 2007

How do I go about tightening it by hand?

Mackinaw · Oct 27, 2007

Jarvman said:
I never realised you're unable to change the lenses mid roll with a TLR which is no good at all

Sure you can. I do it all the time on my C220. Interchangeable lenses are the main reason most folks buy a Mamiya TLR. All you do is turn the knob on the one side of the camera which raises the light baffle. Quick, easy and effective.

Jim B.

Jarvman · Oct 27, 2007

I never realised there was a light baffle. Shows how much research I put into buying this and how much attention I payed to the instruction manual.

Thanks Ian, I'm very grateful. I've had the lens apart and now the problem is solved. I'm once again very happy with this camera! Now to get a roll through it tomorrow.

Mojo_77 · Oct 27, 2007

You can change the lenses on a 330 mid roll, you just turn the dial to the "Unlock" position, and a blind comes over the lens throat.

Ian Tindale · Oct 27, 2007

When it comes time to load film, here's how (something I prepared earlier):
http://www.flickr.com/photos/iantindale/sets/72157594329666989/

rrankin · Oct 27, 2007

Jarvman said:
I never realised you're unable to change the lenses mid roll with a TLR which is no good at all. I'm looking at a modular 6x6 SLR now.

Every Mamiya TLR I've ever had lets you switch lenses mid-roll. Who says you can't?
Richard

k_jupiter · Oct 28, 2007

rrankin said:
Every Mamiya TLR I've ever had lets you switch lenses mid-roll. Who says you can't?
Richard

Jarvman has seen the error of his ways. Just wait till he finds out you can shoot the rest of a roll of film with the baffle closed (at least on a C220). *L*

Then we will see someone really torqued.

J-man, whatcha gonna do with the RZ? It's 6x7 anyway. As far as a good price? I don't know. I do know I could have bought two complete RB67s for that kind of money here in the states.

tim in san jose

Jarvman · Oct 28, 2007

k_jupiter said:
Jarvman has seen the error of his ways. Just wait till he finds out you can shoot the rest of a roll of film with the baffle closed (at least on a C220). *L*
tim in san jose

Thankfully you can't do that on a C330S. The thought entered my head that what you said could happen. When the C330S is in unlock mode it won't allow you to fire the shutter though so it's not a problem.

I didn't really want the RZ. Well, Ideally it'd be nice to have one. Like it'd be nice to have a hassy but I don't want to pay rediculous money. I only placed an offer cause I was drunk at 2 in the morning and feeling disillusioned with the TLR. Bad mistake! I don't want to buy it but the guy on eBay accepted my offer and now I'm obliged to. I explained I don't want to buy it and apologised explaining I'd pay his relisting fees to which he said there was a £15 charge for non paying bidders. It must cost him about £1-2 to relist the thing which I'm willing to pay but not £15. I'm really happy with my TLR now I've sussed out how to use it and fixed my lens thanks to this thread.

Jarvman · Oct 28, 2007

Oh yeah, RB's are interesting. Can you get a 6x6 back for them though? That was the only thing that put me off. I wanted to shoot square. It would've been an idea to crop the 6x7 image. That way I'd have the option of enlarging to the dimentions of the paper if I wanted to. Hmm. I borrowed a mates bronica sq the other weekend and took some photos of waterfalls. It sounds boring but they turned out really well. I love these big ol negs. I haven't printed them yet cause I can only print 35mm from home. I'll have to wait until after the holidays when I get back to uni.

Nick Zentena · Oct 28, 2007

190 GB pounds is what about $400? For a RZPro body with finder I don't think's it's way out of line. Depends on condition of course. I think that's about what KEH is selling bargain grade RZ PRO II.

Of course ou still need to add a lens and a back.

Jarvman · Oct 28, 2007

Yeah it's a pretty good price, but as you said it starts to get expensive when you need to add a back and a lens. I'm hopefully going to pick up another C330S, a C330F, three lenses and a prism finder for £99 or $203 tonight.
RB67's are unbelievebly cheap with a lens too, perhaps I'll look into buying one in future for the 6x7 format and no doubt you can buy a 6x4.5 back for them too right? Although 645 isn't as appealing to me. At least I've got 6x6 covered with the TLR now anyhow.

Nick Zentena · Oct 28, 2007

6x45 backs are much more common then 6x6 backs for the RZ.

It's a big setup for shooting 6x45. Plenty of smaller 6x45 for not much more money then a 6x45 back.

Jarvman · Oct 28, 2007

Nah, I'm on about for the RB now not the RZ.

Shoddy Sekor lens

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