Pentax 77mm repair. DIY attempt?

H. Sapiens · 11-24-2016, 01:41 AM

Hi

I have a 77mm lth where the rear elements have come loose. It is second time this lens falls apart. First time I had in professionally fixed by some super friendly Sikhs, but to be honest they didn't do a good job (always had issues around infinity) and I suspect it fell apart again because they didn't do a good job. That, however, was a repair center in India as I was traveling when it happened.

So now I am considering if I send it off to repair again or attempt to do it myself. The lens is way out of warranty.

I have the tools and motor skills to deal with tiny screws and such, so I think I'll be able to take it apart and but it together again. However, will it perform 100% as supposed ...?! There are some guides on other lenses, but does any of you guys have experience with the 77 you can share?

Or, other option is to send it off. I have bad experience with Pentax service in Denmark, where I live, as well (they charged me more for repair than the lens, a 12-24mm, cost as new. But at least it is working now). Service is now done by a different company, which is located in some small Swedish town. Any experience with these guys? Or some alternatives - there used to be a company in Germany?

Sorry for long post!

**lithedreamer** · 11-24-2016, 02:50 AM

Originally posted by H. Sapiens

Hi

I have a 77mm lth where the rear elements have come loose. It is second time this lens falls apart. First time I had in professionally fixed by some super friendly Sikhs, but to be honest they didn't do a good job (always had issues around infinity) and I suspect it fell apart again because they didn't do a good job. That, however, was a repair center in India as I was traveling when it happened.

So now I am considering if I send it off to repair again or attempt to do it myself. The lens is way out of warranty.

I have the tools and motor skills to deal with tiny screws and such, so I think I'll be able to take it apart and but it together again. However, will it perform 100% as supposed ...?! There are some guides on other lenses, but does any of you guys have experience with the 77 you can share?

Or, other option is to send it off. I have bad experience with Pentax service in Denmark, where I live, as well (they charged me more for repair than the lens, a 12-24mm, cost as new. But at least it is working now). Service is now done by a different company, which is located in some small Swedish town. Any experience with these guys? Or some alternatives - there used to be a company in Germany?

Sorry for long post!

I'm not an expert, but a couple of thoughts:

I believe there's an 'exploded' diagram for this lens. That sounds helpful.
Wall off your deskspace! I've tried opening a lens before, and my kit 18-55 was never the same.
Expect flying springs!

pakinjapan · 11-24-2016, 03:16 AM

Originally posted by lithedreamer

Expect flying springs!

That was what happened to my FA20.
Pentax square in Shinjuku told me it is an old design lens. They cannot open the lens up there for it is no hope to fix my FA20.
so I back home and try it myself ( I open up and fix my DA15 before. ) I try open it from the rear part first. (b/c It seems impossible to open it from the front part.) And as soon as I remove the last screw, those cute tinny springs fly out in all direction! That's when I understand why professional at Pentax square said they cannot open it up. LOL

What I found inside the FA20 is, they have a lot of small gears running along inner lens barrel. Which even If I manage to find all loosen springs + manage to put all of them back, I have no idea what need to be fixed. It looks very complicate in there which is so difference than a newer design lens such as DA15. I guess the same era FA lenses might use a similar design approach? I am not sure about FA limited lenses.

if you really like the lens, let professional check it first, trust me!

Good luck.

H. Sapiens · 11-24-2016, 03:40 AM - **1 Like**

Yes, you are right - I downloaded the diagram dreamer.

I have some experience with manual watches and got a loupe, tiny screwdrivers and such - that's why I'm kinda hopefull :-)

I would still like to hear first hands reports with that lens! Needless to say, it is not a cheap oldie you put on the shelf for display, when you can't get the thing to focus on anything again.

**lithedreamer** · 11-24-2016, 03:58 AM - **1 Like**

Originally posted by H. Sapiens

Yes, you are right - I downloaded the diagram dreamer.

I have some experience with manual watches and got a loupe, tiny screwdrivers and such - that's why I'm kinda hopefull :-)

I would still like to hear first hands reports with that lens! Needless to say, it is not a cheap oldie you put on the shelf for display, when you can't get the thing to focus on anything again.

I'm glad to hear my advice was of some use. The shipping might make this option prohibitive, but I thought I'd throw out the option of sending it to Eric, the independent Pentax expert. This thread is kind of relevant. I searched around the forums and wasn't able to find more helpful threads, sorry!

H. Sapiens · 11-24-2016, 05:13 AM

Originally posted by lithedreamer

I'm glad to hear my advice was of some use. The shipping might make this option prohibitive, but I thought I'd throw out the option of sending it to Eric, the independent Pentax expert. This thread is kind of relevant. I searched around the forums and wasn't able to find more helpful threads, sorry!

That was useful. I realize that I have treated JIS and philips as the same screw. I must look closer what I have among my watch tools, but of course most of the screwdrivers are flat head, which is what is used for watches. I think I have to realize it must be shipped up to those folks in the Swedish forest. It is going to cost a bloody fortune...

My lens looked like Mike's when I first took it to repair in India.

Ontarian50 · 11-24-2016, 08:12 AM

Even if you have the motor skills and mechanical aptitude to deal with the disassembly and re-assembly of a precision item like your 77mm - a big obstacle to DIY camera/lens repair is having the right tools.

High quality screwdrivers are hard to come by (I have to order mine from California). And the various pin spanners, etc. that are essential for some lens designs aren't something ever seen at the local hardware store.

So, to do it right, and not damage anything because of inadequate tools, you have to make an investment in the right stuff. Don't get me wrong, some people really love having a kit of precision tools of their own. But if you don't plan on working on lenses in the long term, get a pro to do it right for you.

H. Sapiens · 11-24-2016, 11:45 AM - **1 Like**

Dude! That's amazing. I only had a glance now, but I don't think it looks too intimidating. I'll buy some Threadlock and give it a go.

Enjoy thanksgiving! We have adopted Halloween and Black Friday and a few other holidays from over there, but don't see the point in giving thanks.

But what the heck ... Thank you!

**WPRESTO** · 11-24-2016, 06:50 PM

A problem I foresee is precision alignment (collimation - decentering) of any lens elements that be be loosened. Not something that can be corrected at home by eye.

**WPRESTO** · 11-25-2016, 05:38 AM

Originally posted by dcshooter

Decentering in a prime is only caused by either an original manufacturing defect (e.g. a mis-cemented doublet) or by physical deformation of a barrel caused by a blow to the lens. As far as "collimation" goes, 99+% of slr lenses can't be collimated, since they are composed of elements held in by fixed retaining rings that can't be adjusted axially. If you've had a tech claim that he collimated a lens for you, you've likely been a victim of fraud.

Screwing and unscrewing enyire lens cells will have absolutely no effect on the centering of a lens, and single elements will only be a problem if you remove them and don't put them in flat. As soon as the surfaces are flat, the mechanical and optical centers of a modern lens are so well aligned that their rotation (the only adjustable parameter) is irrelevant to performance.

OK. I learn something new each day. Way back when I dismantled some ancient lenses (pre WWII), it was necessary to use a spanning wrench to loosen a locking ring to remove at least some lenses from the barrel, and several lenses had "play" when replaced.

HarisF1 · 11-25-2016, 05:56 AM

Try and practice on some old Takumar lenses for a bit of experience.

H. Sapiens · 11-25-2016, 05:58 AM

Originally posted by WPRESTO

OK. I learn something new each day. Way back when I dismantled some ancient lenses (pre WWII), it was necessary to use a spanning wrench to loosen a locking ring to remove at least some lenses from the barrel, and several lenses had "play" when replaced.

I have also only taken one lense apart and put it together (an a-series) and it occured to me that the only thing keeping the elements positioned is production telerances - nothing you can adjust in there.

11-24-2016, 01:41 AM	#1
H. Sapiens Pentaxian Join Date: Feb 2011 Posts: 328	Pentax 77mm repair. DIY attempt? Hi I have a 77mm lth where the rear elements have come loose. It is second time this lens falls apart. First time I had in professionally fixed by some super friendly Sikhs, but to be honest they didn't do a good job (always had issues around infinity) and I suspect it fell apart again because they didn't do a good job. That, however, was a repair center in India as I was traveling when it happened. So now I am considering if I send it off to repair again or attempt to do it myself. The lens is way out of warranty. I have the tools and motor skills to deal with tiny screws and such, so I think I'll be able to take it apart and but it together again. However, will it perform 100% as supposed ...?! There are some guides on other lenses, but does any of you guys have experience with the 77 you can share? Or, other option is to send it off. I have bad experience with Pentax service in Denmark, where I live, as well (they charged me more for repair than the lens, a 12-24mm, cost as new. But at least it is working now). Service is now done by a different company, which is located in some small Swedish town. Any experience with these guys? Or some alternatives - there used to be a company in Germany? Sorry for long post!

11-24-2016, 02:50 AM	#2
lithedreamer Site Supporter Join Date: Sep 2013 Photos: Gallery \| Albums Posts: 1,799	Originally posted by H. Sapiens Hi I have a 77mm lth where the rear elements have come loose. It is second time this lens falls apart. First time I had in professionally fixed by some super friendly Sikhs, but to be honest they didn't do a good job (always had issues around infinity) and I suspect it fell apart again because they didn't do a good job. That, however, was a repair center in India as I was traveling when it happened. So now I am considering if I send it off to repair again or attempt to do it myself. The lens is way out of warranty. I have the tools and motor skills to deal with tiny screws and such, so I think I'll be able to take it apart and but it together again. However, will it perform 100% as supposed ...?! There are some guides on other lenses, but does any of you guys have experience with the 77 you can share? Or, other option is to send it off. I have bad experience with Pentax service in Denmark, where I live, as well (they charged me more for repair than the lens, a 12-24mm, cost as new. But at least it is working now). Service is now done by a different company, which is located in some small Swedish town. Any experience with these guys? Or some alternatives - there used to be a company in Germany? Sorry for long post! I'm not an expert, but a couple of thoughts: I believe there's an 'exploded' diagram for this lens. That sounds helpful. Wall off your deskspace! I've tried opening a lens before, and my kit 18-55 was never the same. Expect flying springs!

11-24-2016, 03:16 AM	#3
pakinjapan Veteran Member Join Date: Jun 2012 Location: Tokyo Photos: Gallery Posts: 1,041	Originally posted by lithedreamer Expect flying springs! That was what happened to my FA20. Pentax square in Shinjuku told me it is an old design lens. They cannot open the lens up there for it is no hope to fix my FA20. so I back home and try it myself ( I open up and fix my DA15 before. ) I try open it from the rear part first. (b/c It seems impossible to open it from the front part.) And as soon as I remove the last screw, those cute tinny springs fly out in all direction! That's when I understand why professional at Pentax square said they cannot open it up. LOL What I found inside the FA20 is, they have a lot of small gears running along inner lens barrel. Which even If I manage to find all loosen springs + manage to put all of them back, I have no idea what need to be fixed. It looks very complicate in there which is so difference than a newer design lens such as DA15. I guess the same era FA lenses might use a similar design approach? I am not sure about FA limited lenses. if you really like the lens, let professional check it first, trust me! Good luck. Last edited by pakinjapan; 11-24-2016 at 03:22 AM.

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11-24-2016, 03:40 AM - 1 Like	#4
H. Sapiens Pentaxian Join Date: Feb 2011 Posts: 328 Original Poster	Yes, you are right - I downloaded the diagram dreamer. I have some experience with manual watches and got a loupe, tiny screwdrivers and such - that's why I'm kinda hopefull :-) I would still like to hear first hands reports with that lens! Needless to say, it is not a cheap oldie you put on the shelf for display, when you can't get the thing to focus on anything again.

11-24-2016, 03:58 AM - 1 Like	#5
lithedreamer Site Supporter Join Date: Sep 2013 Photos: Gallery \| Albums Posts: 1,799	Originally posted by H. Sapiens Yes, you are right - I downloaded the diagram dreamer. I have some experience with manual watches and got a loupe, tiny screwdrivers and such - that's why I'm kinda hopefull :-) I would still like to hear first hands reports with that lens! Needless to say, it is not a cheap oldie you put on the shelf for display, when you can't get the thing to focus on anything again. I'm glad to hear my advice was of some use. The shipping might make this option prohibitive, but I thought I'd throw out the option of sending it to Eric, the independent Pentax expert. This thread is kind of relevant. I searched around the forums and wasn't able to find more helpful threads, sorry!

11-24-2016, 05:13 AM	#6
H. Sapiens Pentaxian Join Date: Feb 2011 Posts: 328 Original Poster	Originally posted by lithedreamer I'm glad to hear my advice was of some use. The shipping might make this option prohibitive, but I thought I'd throw out the option of sending it to Eric, the independent Pentax expert. This thread is kind of relevant. I searched around the forums and wasn't able to find more helpful threads, sorry! That was useful. I realize that I have treated JIS and philips as the same screw. I must look closer what I have among my watch tools, but of course most of the screwdrivers are flat head, which is what is used for watches. I think I have to realize it must be shipped up to those folks in the Swedish forest. It is going to cost a bloody fortune... My lens looked like Mike's when I first took it to repair in India.

11-24-2016, 08:12 AM	#7
Ontarian50 Veteran Member Join Date: Mar 2015 Posts: 530	Even if you have the motor skills and mechanical aptitude to deal with the disassembly and re-assembly of a precision item like your 77mm - a big obstacle to DIY camera/lens repair is having the right tools. High quality screwdrivers are hard to come by (I have to order mine from California). And the various pin spanners, etc. that are essential for some lens designs aren't something ever seen at the local hardware store. So, to do it right, and not damage anything because of inadequate tools, you have to make an investment in the right stuff. Don't get me wrong, some people really love having a kit of precision tools of their own. But if you don't plan on working on lenses in the long term, get a pro to do it right for you.

11-24-2016, 11:45 AM - 1 Like	#8
H. Sapiens Pentaxian Join Date: Feb 2011 Posts: 328 Original Poster	Dude! That's amazing. I only had a glance now, but I don't think it looks too intimidating. I'll buy some Threadlock and give it a go. Enjoy thanksgiving! We have adopted Halloween and Black Friday and a few other holidays from over there, but don't see the point in giving thanks. But what the heck ... Thank you!

11-24-2016, 06:50 PM	#9
WPRESTO Loyal Site Supporter Join Date: Aug 2010 Location: Massachusetts Photos: Gallery \| Albums Posts: 59,104	A problem I foresee is precision alignment (collimation - decentering) of any lens elements that be be loosened. Not something that can be corrected at home by eye.

11-25-2016, 05:38 AM	#10
WPRESTO Loyal Site Supporter Join Date: Aug 2010 Location: Massachusetts Photos: Gallery \| Albums Posts: 59,104	Originally posted by dcshooter Decentering in a prime is only caused by either an original manufacturing defect (e.g. a mis-cemented doublet) or by physical deformation of a barrel caused by a blow to the lens. As far as "collimation" goes, 99+% of slr lenses can't be collimated, since they are composed of elements held in by fixed retaining rings that can't be adjusted axially. If you've had a tech claim that he collimated a lens for you, you've likely been a victim of fraud. Screwing and unscrewing enyire lens cells will have absolutely no effect on the centering of a lens, and single elements will only be a problem if you remove them and don't put them in flat. As soon as the surfaces are flat, the mechanical and optical centers of a modern lens are so well aligned that their rotation (the only adjustable parameter) is irrelevant to performance. OK. I learn something new each day. Way back when I dismantled some ancient lenses (pre WWII), it was necessary to use a spanning wrench to loosen a locking ring to remove at least some lenses from the barrel, and several lenses had "play" when replaced.

11-25-2016, 05:56 AM	#11
HarisF1 Veteran Member Join Date: Apr 2016 Posts: 543	Try and practice on some old Takumar lenses for a bit of experience.

11-25-2016, 05:58 AM	#12
H. Sapiens Pentaxian Join Date: Feb 2011 Posts: 328 Original Poster	Originally posted by WPRESTO OK. I learn something new each day. Way back when I dismantled some ancient lenses (pre WWII), it was necessary to use a spanning wrench to loosen a locking ring to remove at least some lenses from the barrel, and several lenses had "play" when replaced. I have also only taken one lense apart and put it together (an a-series) and it occured to me that the only thing keeping the elements positioned is production telerances - nothing you can adjust in there.