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Old Mar 4, 2009, 3:57 PM   #1
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I have a couple of 20 year old 35mm lenses and I was wandering if there is any problems with using these, such as image quality or coverage of the sensor,
(apart from weight and having to manually focus)?

Thanks
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Old Mar 4, 2009, 4:18 PM   #2
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What lenses? Some older lenses will work fine on current dSLRs, some will work with limited functionality, and some won't work at all.

Ifa lens was good enough for a 35mm film camera, it should be good enough for a dSLR. And dSLRs usually have image sensors that are smaller than 35mm film exposures, so itf the lens covered film, it will cover a digital image sensor.
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Old Mar 4, 2009, 7:13 PM   #3
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Depends on what the lens mount. If they are Pentax lenses, they can be used on the Pentax dSLR cameras without problems (I use some I bought in 1980). If they are M42 screw mount lenses you'd need an adaptor to use on the Pentax cameras. As far as quality - I have old lenses that have excellent quality and one that has always been lousy and still is.

Other camera manufacturers have varying degrees of backwards compatibility, depends on the type of mount.
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Old Mar 5, 2009, 4:11 AM   #4
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They are Pentax bayonet fitting, and they gave good results with film on my old Penta P30n SLR.

One is a Sigma 70-210mm f4-5.6
The other is a Pentax-A 28-80mm f3.5-4.5




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Old Mar 5, 2009, 6:50 AM   #5
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Actually if you haven't decided yet the 4/3 (or micro 4/3) format seems to be the de-facto 'standard' for all kind of old lenses - You can essentially get adapters for almost any brand of lens since they have the shortest flange distance and do not lose any capability of the old lens...

-> if you're a lens collector then this is a real bonus (i.e. a kind of 'universal' body):
http://www.cameraquest.com/adapt_olyE1.htm
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Old Mar 5, 2009, 10:59 AM   #6
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Is the Sigma an "A" lens also (has a spot marked with an "A" on the aperture ring)? It's nice to have that auto-exposure capability, which your Pentax lens will offer you. All old lenses retain whatever capability they had when new - with lenses that have the A on it, the camera can set/control the aperture. A lenses will work just like modern lenses do as far as exposure, you'll just have to manually focus them. It's one less thing to think about (both my macro and my long tele lenses are A lenses and I use them constantly).

If your Sigma doesn't have the "A" setting, it will still work. You have to set the aperture on the lens then push the green button so the camera can temporarily stop down the lens and meter, setting the shutter speed. The lens will be wide open for focusing and only stop down again when you press the shutter (I find it easier for me to set exposure firstthen focus). It actually takes longer to explain it than it does to do it.

One thing about the old lenses and the crop factor with the dSLR sensors being smaller than the film surface - you are using the center part of the lens. I have an old 24mm lens that I thought had too much barreling for me, and was just too wide for how I saw things (and I never used it). Because you aren't using the edges, it's not quite as wide and doesn't show as much fish-eye effect so its far more useful to me.

NHL - A question about the (micro) 4/3 with adaptor - does the adaptor allow any contact between the camera and the lens? The old K-Mount lenses have a lever that allows the camera to stop down the lens when it takes the picture. You can focus, frame etc. everything with the lens wide open, a big advantage if you are using small apertures. If the adaptor for the 4/3 system doesn't allow the camera to use that lever, I would imagine that you'd have to focus wide open, then manually stop the lens down to frame and take the picture. Is this how it works?
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Old Mar 5, 2009, 1:45 PM   #7
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mtngal wrote:
Quote:
NHL - A question about the (micro) 4/3 with adaptor - does the adaptor allow any contact between the camera and the lens? The old K-Mount lenses have a lever that allows the camera to stop down the lens when it takes the picture. You can focus, frame etc. everything with the lens wide open, a big advantage if you are using small apertures. If the adaptor for the 4/3 system doesn't allow the camera to use that lever, I would imagine that you'd have to focus wide open, then manually stop the lens down to frame and take the picture. Is this how it works?
Yes - I'm not too familiar with the Pentax, but on my FD (Canon) lens which has a similar lever if you push this same lever all the way pass the stop-down position it would lock into place

-> This will allow you then to use the aperture ring on the lens to focus at wide open and then close the ring down to the desired aperture for shooting
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Old Mar 9, 2009, 7:17 PM   #8
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NHL wrote:
Quote:
mtngal wrote:
Quote:
NHL - A question about the (micro) 4/3 with adaptor - does the adaptor allow any contact between the camera and the lens? The old K-Mount lenses have a lever that allows the camera to stop down the lens when it takes the picture. You can focus, frame etc. everything with the lens wide open, a big advantage if you are using small apertures. If the adaptor for the 4/3 system doesn't allow the camera to use that lever, I would imagine that you'd have to focus wide open, then manually stop the lens down to frame and take the picture. Is this how it works?
When using Pentax compatible lenses, you need to be careful!!!
The stop down lever doesn't interfere with anything, but if there is a protrusion that PROTECTS the stop down lever, this can foul on the electrical pins in a 4/3 camera, and possibly damage them.
If you remove the protector, you should have no problem.




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