Question: Summarit 35mm f2.5 Aperture Blades

[shogo]

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I just bought a used Summarit 35mm f2.5. My first Leica.

 

At the max aperture (f2.5), I am still seeing the aperture blades through the lens at the edge of the barrel. Is this normal? All the lenses that I have owned do not have this. The aperture blades disappear and gives perfect circle defined by the lens barrel.

 

 

BTW, it came with 2 certificates identifying the serial number corresponding to the lens I bought. One is the test certificate at the production stage. One is customer service certificate. Does this mean this lens was serviced by Leica?

 

Thanks.

[jaapv]

Welcome

 

1. Yes that is perfectly normal with several lenses. See the regular threads we get on the subject

 

2. Yes that means it has been repaired by Leica Customer Service. A good thing. In general the gear leaves the Service in excellent condition and somewhat better adjusted than prodoction models.

[luigi bertolotti]

A bit of "closing" of the diaphragm at maximum aperture is normal on some lenses , both old and new: don't forget that, depending on the glass elements in front of it (typically, a group with convergence effect) it can be that this apparent small closing has no effect at all on the let'say "quantity" of incoming lightrays.

 

Does the customer service certificate have a date ? I suppose it means a service, probably carried on during warranty... what I am sure of is that my Summarit 75, bought new, had only a quality assurance factory certificate.

[01af]

I just bought a used Summarit-M 35 mm 1:2.5. My first Leica.

Good choice! It's an excellent lens with nice bokeh. Personally, I even prefer it over the Summicron-M 35 mm Asph. Its special strength is the far-better-than-average (almost perfect) resistance against reflexes and veiling glare in backlight situations.

 

 

At the max aperture (f/2.5), I am still seeing the aperture blades through the lens at the edge of the barrel. Is this normal?

Yes, it is. Don't ask me why ... but mine does the same. By the way, so does the Summarit-M 50 mm.

 

<speculation>I suppose this design helps keeping vignetting down at full aperture. I guess when the aperture blades would disappear completely then the effective lens speed would be, say, 1:2.4 or 1:2.3—but only at the frame's center, not at the borders. However, I'm just speculating. I don't actually know why the aperture blades don't go out of the way entirely.</speculation>

 

 

BTW, it came with two certificates identifying the serial number corresponding to the lens I bought. One is the test certificate at the production stage. One is customer service certificate. Does this mean this lens was serviced by Leica?

I guess that's what it means.

[Keith (M)]

Presumably a feature of the Summarit range as the blades are visible in my 75mm too.

[shogo]

Welcome

 

1. Yes that is perfectly normal with several lenses. See the regular threads we get on the subject

 

2. Yes that means it has been repaired by Leica Customer Service. A good thing. In general the gear leaves the Service in excellent condition and somewhat better adjusted than prodoction models.

 

Wow! Thank you guys. Very helpful information. I am new to Leica world, so I thought my question would be disregarded... I have been to other forums...

But anyway. Thank you very much for the information.

 

BTW, which one is considered the regular thread?

 

Thanks.

[Shade]

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Welcome

 

1. Yes that is perfectly normal with several lenses. See the regular threads we get on the subject

 

2. Yes that means it has been repaired by Leica Customer Service. A good thing. In general the gear leaves the Service in excellent condition and somewhat better adjusted than prodoction models.

 

I would second what Jaap said.

[andybarton]

 

BTW, which one is considered the regular thread?.

 

Jaap means that threads with similar questions come up regularly.