SLR lens

[Shadowman]

Is it possible that a lens could be manufactured to focus at only one focusing distance? I have some old lenses for a film camera and they only focus at one distance; everything beyond that focusing distance is blurry. The lens is either an Alpa or Albinar lens.

28mm No. 760720
55mm No. 201770

[Manfred M]

That seems to be a rather useless "feature". I would suspect that something has broken inside the lens for this to be happen happening.

[William W]

Is it possible that a lens could be manufactured to focus at only one focusing distance?

Yes.

Are you certain that they were manufactured as SLR Camera Lenses and that they are not Enlarger Lenses capable of being mounted on an SLR Camera?

WW

[Shadowman]

Yes.

Are you certain that they were manufactured as SLR Camera Lenses and that they are not Enlarger Lenses capable of being mounted on an SLR Camera?

WW

Hi Bill,

There is so little information about the lens and camera but I found this manual online that shows the lens mounted on an SLR.

http://www.butkus.org/chinon/alpa/al...lpa_si2000.htm

[Shadowman]

That seems to be a rather useless "feature". I would suspect that something has broken inside the lens for this to be happen happening.

It does make for a time consuming setup.

[Manfred M]

It seems to me that the pin connecting the focusing ring to the focusing helix has likely broken off or possibly worn off. It shouldn't happen but it certainly can.

[William W]

Hi Bill,

There is so little information about the lens and camera but I found this manual online that shows the lens mounted on an SLR.

Hi John,

The lens in the photo on the front of that camera manual is definitely a CAMERA lens.

An ENLARGER LENS does not have a Focusing Turret (not any that I have seen), I should have mentioned that first up, sorry.

So, if the two lenses that you have found, do have Focusing Turrets (aka "Focusing Rings") then they are lenses made for cameras.

I expect that if the Focusing Turret turns but the lens does not change focus distance then there is an internal problem. on the other hand the Focusing Turret could have seized and that could be the problem.

***

Although Enlarger Lenses do not have a Focus Turret, they can be used on cameras. To get an appreciable range of Focusing Distances one needs to use an Helicoid Focusing Tube (aka 'Helicoid Focuser') between the Camera and the Lens: basically this moves the lens to and from the camera body in a smooth motion when the turret is rotated on the Helicoid Focusing Tube.

One can use a set of bellows to achieve the same purpose.

Alpa made Enlarger Lenses {correction*1} and that's why I thought that you might have found an old Enlarger Lens and an old Camera, and not found the Helicoid Focusing Tube which belonged to that kit.

It was not overly common, but common enough, use Enlarger Lenses on SLRs.

WW

Correction {*1} (Pls see Boab's post below and thus a correction to my sloppy writing: I concur I am not aware that Alpa actually 'made' Enlarger Lenses, I should have written that Alpa re-branded lenses - often Rodenstock.)

[tao2]

Hi John,

The reason yer having problems is because of the very short flange focal distance of the lens - around 36/37 mm iirc. That's why the lenses appear tae be fixed focus and behave in a similar way tae enlarger lenses when used on other cameras. Most Nikon cameras have this problem when trying tae use legacy, manual lenses, they need an optical adapter. Your lenses would work perfectly well on Alpa camera bodies.

Alpa didn't make lenses; they would usually be fitted with Kern Macro Switars (50mm). Albinar (just a brand name, ah think an American distributor?) lenses were made by a number of different manufacturers, in the same way as the likes of Vivitar, Porscht, Revuenon would use Tokina, Tamron et al. a few German (Schacht) springs tae mind and Austrian and Swiss (most Albinar lenses are pretty poor). Alpa was originally a Swiss company; the name was bought and revived a number of years ago, with large and medium format cameras being produced...ah believe each camera is custom-made, at a VERY custom price.

Nearly bought a vintage Alpa years ago, the original cameras are things of beauty, superbly engineered as befits Swiss craftsmanship. The lack of interchangeability of lenses prevented that purchase plus the sky-rocketing prices for Alpa -fit lenses.

PS adapters are available for 4/3 and mirrorless cameras tae use these Alpa-fit lenses.

A good example of an Alpa...

[Shadowman]

Hi John,

The reason yer having problems is because of the very short flange focal distance of the lens - around 36/37 mm iirc. That's why the lenses appear tae be fixed focus and behave in a similar way tae enlarger lenses when used on other cameras. Most Nikon cameras have this problem when trying tae use legacy, manual lenses, they need an optical adapter. Your lenses would work perfectly well on Alpa camera bodies.

Alpa didn't make lenses; they would usually be fitted with Kern Macro Switars (50mm). Albinar (just a brand name, ah think an American distributor?) lenses were made by a number of different manufacturers, in the same way as the likes of Vivitar, Porscht, Revuenon would use Tokina, Tamron et al. a few German (Schacht) springs tae mind and Austrian and Swiss (most Albinar lenses are pretty poor). Alpa was originally a Swiss company; the name was bought and revived a number of years ago, with large and medium format cameras being produced...ah believe each camera is custom-made, at a VERY custom price.

Nearly bought a vintage Alpa years ago, the original cameras are things of beauty, superbly engineered as befits Swiss craftsmanship. The lack of interchangeability of lenses prevented that purchase plus the sky-rocketing prices for Alpa -fit lenses.

PS adapters are available for 4/3 and mirrorless cameras tae use these Alpa-fit lenses.

A good example of an Alpa...

Hi Boab,

Thanks for the info, I have the Si 2000 shown in the manual, not as cool as the image you posted though. I can see the camera focusing while mounted on the SLR, can't verify that it truly focused without getting some film and shooting some images. I used a T-NIK adapter when mounted on the DSLR but the aperture of the lens doesn't change; it remains wide open.

[Shadowman]

Hi John,

The lens in the photo on the front of that camera manual is definitely a CAMERA lens.

An ENLARGER LENS does not have a Focusing Turret (not any that I have seen), I should have mentioned that first up, sorry.

So, if the two lenses that you have found, do have Focusing Turrets (aka "Focusing Rings") then they are lenses made for cameras.

I expect that if the Focusing Turret turns but the lens does not change focus distance then there is an internal problem. on the other hand the Focusing Turret could have seized and that could be the problem.

***

Although Enlarger Lenses do not have a Focus Turret, they can be used on cameras. To get an appreciable range of Focusing Distances one needs to use an Helicoid Focusing Tube (aka 'Helicoid Focuser') between the Camera and the Lens: basically this moves the lens to and from the camera body in a smooth motion when the turret is rotated on the Helicoid Focusing Tube.

One can use a set of bellows to achieve the same purpose.

Alpa made Enlarger Lenses and that's why I thought that you might have found an old Enlarger Lens and an old Camera, and not found the Helicoid Focusing Tube which belonged to that kit.

It was not overly common, but common enough, use Enlarger Lenses on SLRs.

WW

Hi Bill,

Thanks for the followup, see post #9 regarding how the lens handles on the Alp Si 2000 camera, it does visually change focus when looking through the viewfinder; something is not working when attached to the DSLR though.

[Shadowman]

It seems to me that the pin connecting the focusing ring to the focusing helix has likely broken off or possibly worn off. It shouldn't happen but it certainly can.

Hi Manfred,

See posts 9 and 10, on the film camera the focusing mechanism (manual focus) seems to work; but when attached to the DSLR there seems to be a disconnect.

[tao2]

Hi John,

The problem with the lens on yer DSLR will be for one of two reasons. If the lens has an Auto/Manual switch, then it must be set tae Manual (and kept in manual) before it'll change aperture on the DSLR. If it doesn't have an A/M switch, then there should be a protruding diaphragm pin at the rear of the lens, usually right next tae the thread/bayonet. This pin has tae be depressed and kept depressed, then the aperture adjustment, again, will be enabled.

Ah sometimes use a small strip of adhesive metal tape tae keep the pin depressed or ye can use gaffer tape etc. A more permanent, elegant solution is tae use a piece of plastic from a cotton bud stem and insert this inside the lens, on the diaphragm pin itself. Ah may have examples somewhere if ye want tae try this.

After all this, and the lens is focusing correctly, then ye'll have a further problem - if ye use a Nikon camera. Again, because of the Nikon's flange focal distance, ye'll need an optical adapter tae compensate for this. This adapter will reduce image quality noticeably, most times, very noticeably.

[Shadowman]

Hi John,

The problem with the lens on yer DSLR will be for one of two reasons. If the lens has an Auto/Manual switch, then it must be set tae Manual (and kept in manual) before it'll change aperture on the DSLR. If it doesn't have an A/M switch, then there should be a protruding diaphragm pin at the rear of the lens, usually right next tae the thread/bayonet. This pin has tae be depressed and kept depressed, then the aperture adjustment, again, will be enabled.

Ah sometimes use a small strip of adhesive metal tape tae keep the pin depressed or ye can use gaffer tape etc. A more permanent, elegant solution is tae use a piece of plastic from a cotton bud stem and insert this inside the lens, on the diaphragm pin itself. Ah may have examples somewhere if ye want tae try this.

After all this, and the lens is focusing correctly, then ye'll have a further problem - if ye use a Nikon camera. Again, because of the Nikon's flange focal distance, ye'll need an optical adapter tae compensate for this. This adapter will reduce image quality noticeably, most times, very noticeably.

Hi Boab,

The lens has A/M switch and the protruding pin, it does depress when I switch to manual and the aperture does change when the dial is rotated; however lens still does not focus unless I'm at minimum focusing distance of five feet and interestingly the lens is set at infinity at this distance. And yes using a Nikon camera.

[tao2]

A misplaced/dislodged lens element(s)? Rear or front element removed or removed and reversed tae enable "soft focus"? Running out of ideas here...

PS can ye put up a photo of the lens front, side and rear? Showing the lens markings.

[Shadowman]

Hi Boab,

Here are three quick shots.

135mm on left, 28mm on right

[Shadowman]

Purchazed an M42 to F mount adapter and lens behaved as A normal manual focue lens, unfortunately captured images were very soft and exhibited a blue color cast in certain lighting conditions. The 55mm looked better than the 28mm captures, haven't tried the 135mm yet. Tried manual focus through viewfinder, liveview/magnified, and zone focusing. Will look for better glass later and stick with my AF lenses. Thanks all for responding.

[Shadowman]

f/8, 1/30sec, ISO 200