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Forum: Repairs and Warranty Service
03-05-2024, 03:28 PM
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I have discovered that the humble DA18-55 kit lens (and probably other Pentax lenses as well) has the same spring in the same location doing the same job as in the 16-85 and 18-135 lenses. Interestingly
it is also secured on the non moving end by some kind of lacquer glue. Also access to the spring is the same (even easier on the DAL versions).
If you have a suitable donor lens and are keen to remove the spring and transfer it to another lens I would suggest a couple of things to aid the process of removing the donor spring. 1) Tie some sewing thread or similar to the middle of the spring and tether it so the spring will not fly off and get lost and 2) wet the end of a Q tip with lacquer thinner and use it to dissolve the glue retaining one end of the spring before removing it and 3) keep the spring tethered until it is successfully installed in its new home.
Good luck!
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Forum: Repairs and Warranty Service
11-05-2023, 03:13 PM
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I have measured the physical dimensions of the spring and have found a source of possible replacements. The dimensions do not match exactly but it might be close enough . I don't have the equipment to measure the spring rate so I have to go by physical dimensions alone. I have a working copy of both the 16-85 and the 18-135 lenses but I don't feel like partly disassembling a working lens to use it for a test bed. If a suitable replacement spring can be found it would be a boon to owners of these nice lenses who have suffered the spring detachment problem and the spring has been lost. If anyone out there has a lens in that condition and is willing to volunteer it for use as a test bed send me a private message and we'll see what can be worked out.
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Forum: Monthly Photo Contests
07-06-2023, 01:08 PM
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This bridge is on Cal Trans "hit list" for replacement but no one wants to see it go. It is one of the last wooden (mostly) bridges.
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Forum: Pentax K-30 & K-50
03-02-2023, 02:34 PM
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Hello. I live a bit up the coast from you in Fort Bragg and I have replaced the solenoid in four of my own cameras-one K-50, two K-30's and one KS-2 all successfully. I would be glad to help if I can. Perhaps if you found yourself in the area we could arrange a sort of hands on replacement session. Cheers, Ken.
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Forum: Troubleshooting and Beginner Help
02-22-2023, 12:51 PM
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The problem you are having sounds like a spring out of place. I have fixed the same problem on an identical lens and it it a simple fix (so long as you have the missing spring in hand). The spring could have fallen out on the ground when you dismounted the lens, or it could be rattling around in the lens someplace or it could have migrated in to the mirror box on the camera. It is not very big-about 1/8 inch in diameter and about 1/2 inch long (or thereabouts). The job of replacing it requires a bit of delicate work but is minimally invasive as far as the lens is concerned. Good luck, Ken.
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Forum: Troubleshooting and Beginner Help
02-05-2023, 08:07 PM
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There is a small coil (extension) spring that is responsible for the spring return of the aperture control lever and thus the movement of the aperture blades themselves. If, by manually moving the aperture lever, you can open and close the blades (with no automatic spring return) then the spring has likely come adrift. If the spring is not in its place it has to be somewhere-inside the lens mechanism or perhaps in the mirror box on the camera itself. If the spring is lodged in the lens somewhere it could be the cause of the other problems that you mentioned. The spring is somewhere around 1/8 inch in diameter and about 1/2 inch long (approximate dimensions). If you can locate the spring then the replacement of the spring is not at all difficult. The spring is held in place on the stationary end by a dab of glue the failure of which gives rise to the problem. The spring is normally located very close to the camera end of the lens and this makes the replacement easier. Good luck! Ken
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Forum: Monthly Photo Contests
01-04-2023, 05:51 PM
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Camera, lens and ring flash (Vivitar Macroflash 5000) all oldies but goodies-mixed in with a good bit of dumb luck.
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Forum: Monthly Photo Contests
05-02-2021, 03:28 PM
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Ring flash was used. Flowers were a bit less than 1/2 inch in diameter. Picture was taken hand held.
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Forum: Flashes, Lighting, and Studio
04-20-2021, 10:18 AM
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Hello. I have both the DFA 50 and 100 lenses and, while I appreciate their optical quality and light weight, their mostly plastic construction makes it inadvisable to hang something as heavy as a ring flash on the end of the extendable part of the lens. Pentax of course acknowledged this when they provided for the genuine Pentax flashes to be attached to the lens barrel the same as the lens hood. I have modified an old (but still available for cheap on eBay) Vivitar Macroflash 5000 to bayonet on to the front of the lens the same as the lens hood and I am quite happy with the results. I also modified the flash for complete manual control of the light output. In the way of a disclaimer I have to confess that I have a very well equipped shop at my disposal and this enables me to do things that would be difficult for some people. I machined (on my lathe) an adapter made of plastic (UHMW I think) that ,on one end, is glued to the back of the flash unit and the other end bayonets to the front of the lens where the hood would normally mount. It makes for a nice compact and light installation. Probably some clever thinking could come up with a way of doing this utilizing the existing lens hood without having to make a special part on the lathe. The necessary modifications to the flash unit are fairly trivial. Incidentally the trigger voltage on the flash unit is safe for the camera. If anyone is seriously interested in doing this I could probably post a more detailed (and somewhat long winded) set of instructions. Cheers, Ken
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Forum: Lens Clubs
03-17-2020, 09:53 AM
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The lens communicates with the camera (for A lenses at least) via six electrical contacts. One of these is recessed slightly in to the lens mount (this is the one that tells the camera that the lens is an A lens) so the mount plate on the lens itself has to have a pin that protrudes slightly and is electrically connected to the mount plate itself and also has to be spring loaded so that it can move as the lens is mounted (this is usually the tricky part). The other five pins code for the minimum and maximum aperture of the lens by either contacting the lens mount plate or by contacting an insulated spot. The places where the pins contact has to be located on the lens (I made a template for that purpose) and the spots that need to be insulated can be determined by consulting the various sources of information on the K mount (there is one on this forum I believe). The insulated spots can be provided by dimpling the spot with a twist drill and then filling the dimple with clear (electrically non conducting) epoxy. The movable grounding pin is another story as it depends on factors that have to be evaluated once the mount has been removed from the lens-every one is different. Once the modification is done the camera will always see the lens as an "A" lens no matter the setting of the aperture ring (the aperture ring has to be set to the smallest aperture setting to allow the camera full control of the aperture). This can be advantageous in the case of a camera with the "aperture control block" problem because, by setting the aperture ring to the desired value instead of the minimum setting, it prevents the camera from closing the aperture completely as it tries to do. I hope that this rather wordy description doesn't muddy the water instead of clarifying it.
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Forum: Lens Clubs
03-16-2020, 04:31 PM
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Hello all. I have four Rikenon P lenses-three 50mm f2 and one 35 to 70mm macro zoom. All four have been converted by me to function as "A" lenses. The zoom was the last one I did and it is by far the prettiest job but all work fine. It is a bit fiddly but possible.
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Forum: Digital Processing, Software, and Printing
03-16-2020, 03:28 PM
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The post by zzeitg caused me to remember that I had a copy of the Google free NIK Collection so I installed it in Affinity Photo and it seems to work just fine. Now all I have to do is figure out how they work.
I have discovered an interesting little Affinity tweak (maybe everyone already knows about this but I will describe it anyway). In the Photo personna under filters>distortion>spherical there are two sliders-one to control the strength of the effect and the other to control the area affected. The range of the area control can be expanded far beyond the limit of the slider by typing in a larger number in the box to the right of the slider. You have experiment a bit but by typing in numbers in the range of 3000 I can use the strength control to affect the amount of stretching of the sides of the image that occurs when using very wide angle lenses.
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Forum: Repairs and Warranty Service
02-09-2020, 06:39 PM
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The "Jubilee Clip" idea sounds good but I think that I would instead use some clear two-part epoxy glue because I don't think that it gives off much in the way of gas and it is slower setting so you have more time to get it right. Use the tip of a toothpick or something similar to work a small amount of glue it to the crack.
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Forum: Pentax SLR Lens Discussion
03-09-2019, 07:46 PM
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For texandrews: I see that you are looking for a way to minimize the edge distortions caused by wide angle lenses. I have been a big fan of wide angle lenses for years I found something that works (for me at least). I have been using Paint Shop Pro (either jasc or Corel versions) for quite a while. My current version is Corel PSP X6 (not the latest by any means). If you open a photo in PSP and go to the Edit screen select Effects>Distortion Effects>Punch. The amount of the effect is adjustable and if you play around with it you might be pleased. I know that PSP isn't everyone's cup of tea but I have always liked it. If necessary I suppose that you could download a trial copy to see if it works for you. I can only assume that the effect is present in the latest version. P.S. This is my first post on the forum so I hope that I am getting off on the right foot.
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