SMC Pentax-A 50 1.4 - greasing guide?

awscreo · 03-11-2017, 08:22 AM

Hi! I've just received the lens I've purchased from ebay. Optically and cosmetically it seems near mint, very nice condition. I can't see any scratches, haze, fungus, or any other imperfections, just looks very well maintained (and possibly not used much). One thing I've noticed is that the focus ring is a big loose and feels like the old grease might've dried out - feels a bit "scratchy" to turn, not smooth as it should be. Is there a disassembly guide somewhere I can follow to open it up and fix it? I've done so for my Helios 44k-4, with good results. I have nice synthetic grease I've purchased to fix my stiff focus ring on Helios, and a set of screwdrivers that should work. Any advice would be much appreciated

Not a Number · 03-11-2017, 09:06 AM

Originally posted by dcshooter

Reassemble in the reverse order (placint the contact can be tricky - put thering to A, then put the tiny pieces in and turn it to a different aperture, and they should stay in place. Tweezers help.

Be careful not to get grease (unless it is conductive) on the contact parts. Otherwise you might end up having to take the contact parts out to clean them all over again. Working on my SMC-A f/17 fiddling with the contact parts was the most frustrating as they are very tiny and falls apart quite easily.

awscreo · 03-11-2017, 10:23 AM

lol, look the back plate off, and immediately regretted it, as it took me an hour to get that tiny spring with the l-shaped bracket back into place xD sucks that front doesn't have holes to unscrew it easily, i guess I need some sort of a suction cup/wrench, or come up with a dyi method to take that plate off to access screws in the back. pretty annoying xD

awscreo · 03-11-2017, 11:04 AM

Hmm I have the m42 cap, will try, thanks!

**Just1MoreDave** · 03-11-2017, 11:28 AM

I have a vague memory that the A50/1.4 has grub screws on the front barrel, not the more common screws under the trim ring. Try focusing the lens to the minimum distance so the barrel sticks out as much as possible, then look all around the barrel just above the focus ring. If I am right, you'll see a small slotted screw, which you can loosen a few turns. Then the front barrel unscrews and you can proceed. Remember to focus back to infinity so you cam mark its position.

awscreo · 03-11-2017, 11:39 AM

Originally posted by Just1MoreDave

I have a vague memory that the A50/1.4 has grub screws on the front barrel, not the more common screws under the trim ring. Try focusing the lens to the minimum distance so the barrel sticks out as much as possible, then look all around the barrel just above the focus ring. If I am right, you'll see a small slotted screw, which you can loosen a few turns. Then the front barrel unscrews and you can proceed. Remember to focus back to infinity so you cam mark its position.

That might be the reason "glove on a m42 cap" doesn't work

I noticed the tiny screw on the side, but unfortunately the screw is just too small for my kit, I'll shop for smaller watchmakers kit I guess. Thanks! Hope I can fix the lens, glass is so clean, and the body it came with still had few clear plastic film stickers, I guess it just wasn't used much together with the lens)

tom1803 · 03-11-2017, 03:44 PM

On the A50/1.4, the trim ring or the ring with the lettering on it is not threaded.

You need to remove the rubber focus grip first and then you will see three holes. You poke a screwdriver in to those holes to release a catch. Be careful not to use too much force as you may break the plastic clips.

You then loosen the grub screw on the filter mounting ring and unscrew that to get full access.

awscreo · 03-11-2017, 04:46 PM

Originally posted by tom1803

On the A50/1.4, the trim ring or the ring with the lettering on it is not threaded.

You need to remove the rubber focus grip first and then you will see three holes. You poke a screwdriver in to those holes to release a catch. Be careful not to use too much force as you may break the plastic clips.

You then loosen the grub screw on the filter mounting ring and unscrew that to get full access.

Thanks, will try. So the rubber grip part can just be peeled off? It seemed kind of solid to me, wasn't sure it was evem rubber, hope it won't crack

tom1803 · 03-11-2017, 06:19 PM

Yes, the grip just peels off. I've worked on at least 20 or so of these lenses so i'm quite sure.

Use a thin piece of wood like an ice cream/popsicle stick and work around the lens gently.

awscreo · 03-11-2017, 06:42 PM

Originally posted by tom1803

Yes, the grip just peels off. I've worked on at least 20 or so of these lenses so i'm quite sure.

Use a thin piece of wood like an ice cream/popsicle stick and work around the lens gently.

Good) I might come back with more questions

awscreo · 03-11-2017, 10:31 PM

Originally posted by tom1803

On the A50/1.4, the trim ring or the ring with the lettering on it is not threaded.

You need to remove the rubber focus grip first and then you will see three holes. You poke a screwdriver in to those holes to release a catch. Be careful not to use too much force as you may break the plastic clips.

You then loosen the grub screw on the filter mounting ring and unscrew that to get full access.

Hmm, those clips don't seem to give in, and get a bit dented when I press with the screwdriver. I'm afraid to snap them if I press any harder. I guess I'll wait for the smaller screwdrivers to arrive to take off the front filter mounting plate and see if I can go from there, although I believe I'd need to take off the focus ring at some point anyway, maybe need to find something less obtrusive than a sharp-ish screwdriver.

Another question - is it possible to tighten the focus ring a bit as well as greasing it? It seems to turn too easily, and I'd imagine with fresh grease it'll turn even faster. I prefer to have it turn slower and more precise since it's a 1.4.

awscreo · 03-13-2017, 10:32 AM

Can anyone advise on tightening focus ring a bit? I think after greasing it up it'll be too loose. My screwdrivers should arrive tomorrow, so I'll give it another try)

Not a Number · 03-14-2017, 08:07 PM

Originally posted by awscreo

Can anyone advise on tightening focus ring a bit? I think after greasing it up it'll be too loose. My screwdrivers should arrive tomorrow, so I'll give it another try)

"Stiffness" of the focusing ring depends on the grade of the grease you use. See the NLG rating (National Lubricating Grease Institute grade. The higher the number the "stiffer" the grease.

awscreo · 03-15-2017, 06:14 AM

Originally posted by Not a Number

"Stiffness" of the focusing ring depends on the grade of the grease you use. See the NLG rating (National Lubricating Grease Institute grade. The higher the number the "stiffer" the grease.

I haven't applied my grease to it yet, my shipment with screwdrivers is being delayed due to a crazy blizzard we were under yesterday. The focus ring is loose as is, and feels like the grease is dried out (has that "dry" feeling when you're turning the ring). Maybe when I try my grease it'll be more stiff (that I prefer anyway for precise focus). My Helios 44k ended up being almost perfect in terms of amount of force I need to use to turn it.

awscreo · 03-15-2017, 03:59 PM

Awesome, I've managed to pull everything apart, remove remains of the old grease, apply new grease, and put it back together. Now it turns smoothly

also, when I took it apart I've noticed that everything looked almost new, I guess either no one used the lens and kept it safe all these years. Feels like a good ebay find)

03-11-2017, 08:22 AM	#1
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722	SMC Pentax-A 50 1.4 - greasing guide? Hi! I've just received the lens I've purchased from ebay. Optically and cosmetically it seems near mint, very nice condition. I can't see any scratches, haze, fungus, or any other imperfections, just looks very well maintained (and possibly not used much). One thing I've noticed is that the focus ring is a big loose and feels like the old grease might've dried out - feels a bit "scratchy" to turn, not smooth as it should be. Is there a disassembly guide somewhere I can follow to open it up and fix it? I've done so for my Helios 44k-4, with good results. I have nice synthetic grease I've purchased to fix my stiff focus ring on Helios, and a set of screwdrivers that should work. Any advice would be much appreciated

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03-11-2017, 09:06 AM	#2
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Originally posted by dcshooter Reassemble in the reverse order (placint the contact can be tricky - put thering to A, then put the tiny pieces in and turn it to a different aperture, and they should stay in place. Tweezers help. Be careful not to get grease (unless it is conductive) on the contact parts. Otherwise you might end up having to take the contact parts out to clean them all over again. Working on my SMC-A f/17 fiddling with the contact parts was the most frustrating as they are very tiny and falls apart quite easily.

03-11-2017, 10:23 AM	#3
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	lol, look the back plate off, and immediately regretted it, as it took me an hour to get that tiny spring with the l-shaped bracket back into place xD sucks that front doesn't have holes to unscrew it easily, i guess I need some sort of a suction cup/wrench, or come up with a dyi method to take that plate off to access screws in the back. pretty annoying xD

03-11-2017, 11:04 AM	#4
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	Hmm I have the m42 cap, will try, thanks!

03-11-2017, 11:28 AM	#5
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	I have a vague memory that the A50/1.4 has grub screws on the front barrel, not the more common screws under the trim ring. Try focusing the lens to the minimum distance so the barrel sticks out as much as possible, then look all around the barrel just above the focus ring. If I am right, you'll see a small slotted screw, which you can loosen a few turns. Then the front barrel unscrews and you can proceed. Remember to focus back to infinity so you cam mark its position.

03-11-2017, 11:39 AM	#6
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	Originally posted by Just1MoreDave I have a vague memory that the A50/1.4 has grub screws on the front barrel, not the more common screws under the trim ring. Try focusing the lens to the minimum distance so the barrel sticks out as much as possible, then look all around the barrel just above the focus ring. If I am right, you'll see a small slotted screw, which you can loosen a few turns. Then the front barrel unscrews and you can proceed. Remember to focus back to infinity so you cam mark its position. That might be the reason "glove on a m42 cap" doesn't work I noticed the tiny screw on the side, but unfortunately the screw is just too small for my kit, I'll shop for smaller watchmakers kit I guess. Thanks! Hope I can fix the lens, glass is so clean, and the body it came with still had few clear plastic film stickers, I guess it just wasn't used much together with the lens)

03-11-2017, 03:44 PM	#7
tom1803 Veteran Member Join Date: Feb 2010 Location: Kokubunji, Tokyo Photos: Gallery Posts: 465	On the A50/1.4, the trim ring or the ring with the lettering on it is not threaded. You need to remove the rubber focus grip first and then you will see three holes. You poke a screwdriver in to those holes to release a catch. Be careful not to use too much force as you may break the plastic clips. You then loosen the grub screw on the filter mounting ring and unscrew that to get full access.

03-11-2017, 04:46 PM	#8
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	Originally posted by tom1803 On the A50/1.4, the trim ring or the ring with the lettering on it is not threaded. You need to remove the rubber focus grip first and then you will see three holes. You poke a screwdriver in to those holes to release a catch. Be careful not to use too much force as you may break the plastic clips. You then loosen the grub screw on the filter mounting ring and unscrew that to get full access. Thanks, will try. So the rubber grip part can just be peeled off? It seemed kind of solid to me, wasn't sure it was evem rubber, hope it won't crack

03-11-2017, 06:19 PM	#9
tom1803 Veteran Member Join Date: Feb 2010 Location: Kokubunji, Tokyo Photos: Gallery Posts: 465	Yes, the grip just peels off. I've worked on at least 20 or so of these lenses so i'm quite sure. Use a thin piece of wood like an ice cream/popsicle stick and work around the lens gently.

03-11-2017, 06:42 PM	#10
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	Originally posted by tom1803 Yes, the grip just peels off. I've worked on at least 20 or so of these lenses so i'm quite sure. Use a thin piece of wood like an ice cream/popsicle stick and work around the lens gently. Good) I might come back with more questions

03-11-2017, 10:31 PM	#11
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	Originally posted by tom1803 On the A50/1.4, the trim ring or the ring with the lettering on it is not threaded. You need to remove the rubber focus grip first and then you will see three holes. You poke a screwdriver in to those holes to release a catch. Be careful not to use too much force as you may break the plastic clips. You then loosen the grub screw on the filter mounting ring and unscrew that to get full access. Hmm, those clips don't seem to give in, and get a bit dented when I press with the screwdriver. I'm afraid to snap them if I press any harder. I guess I'll wait for the smaller screwdrivers to arrive to take off the front filter mounting plate and see if I can go from there, although I believe I'd need to take off the focus ring at some point anyway, maybe need to find something less obtrusive than a sharp-ish screwdriver. Another question - is it possible to tighten the focus ring a bit as well as greasing it? It seems to turn too easily, and I'd imagine with fresh grease it'll turn even faster. I prefer to have it turn slower and more precise since it's a 1.4.

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03-13-2017, 10:32 AM	#12
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	Can anyone advise on tightening focus ring a bit? I think after greasing it up it'll be too loose. My screwdrivers should arrive tomorrow, so I'll give it another try)

03-14-2017, 08:07 PM	#13
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Originally posted by awscreo Can anyone advise on tightening focus ring a bit? I think after greasing it up it'll be too loose. My screwdrivers should arrive tomorrow, so I'll give it another try) "Stiffness" of the focusing ring depends on the grade of the grease you use. See the NLG rating (National Lubricating Grease Institute grade. The higher the number the "stiffer" the grease.

03-15-2017, 06:14 AM	#14
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	Originally posted by Not a Number "Stiffness" of the focusing ring depends on the grade of the grease you use. See the NLG rating (National Lubricating Grease Institute grade. The higher the number the "stiffer" the grease. I haven't applied my grease to it yet, my shipment with screwdrivers is being delayed due to a crazy blizzard we were under yesterday. The focus ring is loose as is, and feels like the grease is dried out (has that "dry" feeling when you're turning the ring). Maybe when I try my grease it'll be more stiff (that I prefer anyway for precise focus). My Helios 44k ended up being almost perfect in terms of amount of force I need to use to turn it.

03-15-2017, 03:59 PM	#15
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	Awesome, I've managed to pull everything apart, remove remains of the old grease, apply new grease, and put it back together. Now it turns smoothly also, when I took it apart I've noticed that everything looked almost new, I guess either no one used the lens and kept it safe all these years. Feels like a good ebay find)