75 'cron and frame lines

[Steve Fines]

Hi,

I'm looking at a new 75 cron asph. Latest model.

My test shots on an M9 show the lens to be a great performer.

However, when I mount the lens on the M9 the 35/135 frames lines show up in the finder. To get the 50/75 lines I have to manually move the lever medially to the middle position, and hold it there.

My 50mm lens, when mounted brings up the 50/75 lines.

Is there something odd about this 75? Or is that the way it is? I've had one before but just cannot remember.

thanks,

 

[glenerrolrd]

Steve

It should bring up the 50/75 framelines. If you have a 50 see if it still brings up the FL otherwise its the lens. Not positive but I believe the 28/135 frame is up with no lens which would indicate that the flange on the inside of the mount has slipped.

This is something that DAG can handle with a minimum cost .

Good luck getting it right the lens is a winner .

 

[Knorp]

The 75 frame lines are definitely odd, but at least you should have to 50/75 pair.
Looks like something is wrong here, Steve. Does your camera recognize it as a 75'cron ?

All the best.

 

[Steve Fines]

Thanks for the quick replies.

Knorp - my camera does not see it as a 75 cron, but rather as 'uncoded'. Looking at the coding marks compared with my 50 they are about 2-3mm "off" compared to a similar metal piece on the mount.

So it seems the flange on this 75 is not quite aligned properly. Odd given that the focus testing and resolution chart test shots look perfect.

 

[Steve Fines]

After looking at a few more photos this 75 'cron has a slightly misaligned flange.

This is my second "new" Leica lens in a row (first was the Noctilux 0.95) that needs to go to NJ for repair right after purchase. My 2nd M9 also had problems out of the box.

I'm glad for Leica's increased demand and sales, but fear it is coming at a not insignificant cost.

 

[jlm]

make sure the lens is fully rotated onto the body and you note the stop clicking in. since the 35 lines come up, the indication is that the internal lever is not being fully engaged. the 28 tab moves the lever the most, then the 50, and the 35 does not move it at all. the relative engagement distances are about 1/32", so a little bit of not being fully rotated can make a significant difference.

it is possible a new lens is a bit tight and may require a few fittings to bed in. sometimes the stop engagement itself can be tight as well

 

[Steve Fines]

Hey jim,

Thanks for the idea. I've been looking at the lens and figuring out how it works. This one is 2.5-3mm off, so it isn't even close. If I could turn the lens a little more past locking then it would work, but it would also likely break.

Funny thing is that I ran it though some focus tests and resolution charts and it is spot-on. Really great. I've written a note to the NJ folks to just turn the flange a little and not touch anything else, as I really like all the other aspects of this lens.

 

[ggriswold]

Steve, can you take a close up of the rear of the lens? I am trying to imagine how a flange that is screwed into the lens barrel could be so whacked out. I would be really curious to see it... inquiring minds....
I bought a used 50mm Summicron on Ebay once that the front 1/2-1/3 of the lens was rotated 60 degrees... that went right back to the seller. Amazing.

 

[Steve Fines]

Hi,

Think I figured it out.

George - I just had time for one quick snap - as I was taking the photo I heard the delivery truck pull up and had to repack the lens.

On the photo I've drawn a line through a notch and then over the coding marks. The line labeled "50" is where this line would be on my 50mm lens. They should be the same.

The same 2mm discrepancy could be shown most all the way around the lens, but was easiest to see where things lined up - as on the coding marks and the curve of the flange where the cam goes to adjust the field selector knob.

Now, here's the rub.

I looked up the coding on this lens, just to check. Turns out it is coded as a 135 Elmarit. If you are interested, codes are here:

http://whimster-photography.com/leica_m_lens_codes/index.html

I have the receipt with matching serial numbers for the lens showing that NJ says they coded this lens.

My hunch is that when you send a lens to NJ they remove the flange (or whatever that silver part on the back with 6 screws is called) and then screw in a new one that is coded.

I suspect they accidentally put a 135 Elmarit flange on this lens.

Anyway, it is now in transit to that State of many freeway exits. Hopefully it comes back as optically sharp as I sent it off, with a new shiny and properly coded flange.

Or maybe I've got it wrong - but that's my guess.

 

[ggriswold]

Thanks Steve... that is very strange. Guess they are too busy over there!

 

[GrahamWelland]

Thanks Steve... that is very strange. Guess they are too busy over there!

Sorry to be blunt but p*** poor quality control/assurance is what it is ... That's simply unforgivable. Someone screwed up as you'd think that they'd actually check their work and see that the lens works and codes correctly before sending it back out.

I had a 90 Elmarit-M coded at NJ and they sent it back with surface blemishes on the hood that weren't there when I sent it off so I'm not overly surprised by Leica NJs quality of work these days.

 

[ggriswold]

Idea #1... work on a lens then put it on a camera just to see if if works.

 

[M5-Guy]

an amazing tale of misfortune...

Maybe Leitz should engrave in the mount, the lens flange coding "28/90" "50/75" "35/135".
This would help the bench workers put things back on the correct lens, if they have several lenses their working on.... Sheeeesh..
Hope it comes back better than new!

 

[ggriswold]

I think they should throw you a 50mm 1.4 Summilux just to patch things up. I'm just saying.

 

[dannh]

Hey Steve,

Comparing your picture to my factory coded 75 cron (ie. it was originally built as a coded lens) it's identical to your lens. The coding is identical as are the flange positions. The 135 coding is similar, but flipped from the 75.

On the flange positions, I'll admit it's hard to say if your picture exactly matches with my lens, but eyeballing it, it's got to be pretty darn close.

Dan

 

[dannh]

For reference:

Looks pretty much the same to me

 

[thrice]

That is not the flange that determines the framelines. The one that determines framelines differs in size from lens to lens and has a flat edge, I would have thought that to be obvious. Look inside your camera and you will see where the frameline lever is triggered, it is NOT behind the coding sensor.

 

[Per Ofverbeck]

OK, maybe a bit late if the lens is returned, but here is the anterior part of my 75/2 (that works perfectly). As you can see, the coding is the same as yours, but unfortunately your image has the lens index marks cut off, so the angular position is difficult to compare.

The keying on your flange does look a bit shorter than mine, in fact it indeed looks just like the 35/135 position.

 

[Steve Fines]

That is not the flange that determines the framelines. The one that determines framelines differs in size from lens to lens and has a flat edge, I would have thought that to be obvious. Look inside your camera and you will see where the frameline lever is triggered, it is NOT behind the coding sensor.

Hi,

I would have taken some photos of the part where the framelines are selected, but ran out of time as the delivery truck arrived.

As I tried to say, this is my hunch and I certainly could be wrong. I do average being wrong about 617 times/day, so keep that in mind.

However, having this 75 and a 50 right beside each other made it easy to compare exact points on each lens. They were not the same. Just like the coding line I drew, the part of the lens that that selects the framelines was shifted just a little from the same point on the 50.

Looking at the mechanism of how it works, this would explain why the 75 brought up the 35/135 lines but my 50 pushed the cam another few mm and brought up the 50/75 lines.

Anyway, maybe best that I not speculate further. The lens will be back from Leica soon enough and I'll post their findings then.

 

[thrice]

Steve, I am 100% certain that the flange you highlighted has nothing to do with framelines. You have your camera, look inside.

Per is right on the money.