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Forum: Pentax SLR Lens Discussion
04-16-2021, 01:02 AM
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There actually was a Tamron Pentax KA adapter to do officially what I built myself. Whether it is worth to experiment with these mods?
I have sold my Pentax gear years ago because I didn't want to wait for the solenoid problem to get to my K-30 and K-r.
My Q7 and Q-S1 still do well and are used a lot.
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Forum: Pentax SLR Lens Discussion
04-15-2021, 11:22 PM
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Forum: Pentax SLR Lens Discussion
04-15-2021, 11:18 PM
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On the M lenses linearity was not a documented feature but the non-linearity wasn't one too. So different objectives will behave diccerent after this modification. When you look at objectives from other brands with PK mount things are different again. I have modified a Tokina 17/3,5 that had a halfway linear aperture, good enough for practical use. Only on very high aperture numers a real non-linearity showed.
I have also modified an early Tamron 90/2,5 macro, first or second model, that had a nicely linear aperture.
The isolators are easy to make, mill a flat hole, fill with epoxy. The sprung ball bearing is difficult as there is little room for a spring and the ball musn't come out.
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Forum: Pentax Q
11-10-2016, 02:19 PM
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Hi zwmg,
when I read that you are about to do extensive traveling my first thought was: "Why is the thinking any longer about buying a second body?" It really would be a pity it you had to carry all your camera kit through whole Australia without using it because the body broke down.:(
Which model to buy: They are all nice, but I prefer the Q7 and Q-S1.
I first had the original Q but I was not perfectly happy with the image quality. Images always seemed to be slightly unsharp. The camera processor also was decidedly on the slow side.
Then I bought a Q7, which offers just that bit better image quality that I missed from the Q and is more responsive. It feels nearly as solid and handles a bit better than the Q. Now I also have a Q-S1, bought as a second body. It is a girl-camera: Cream white with gold! :hmm: The Q-S1 handles a bit worse and I have the impression that the designer who constructed the new housing was not given quite enough time to do a really good job. In everyday use I just grab one of them and don't care for the slight differences.
Where to buy: I bought my original Q new as a sell off item for 185€ with the 01 lens. I sold it 2 years later for about 90€ body only. The Q7 has cost new 200€ with 02 lens. The Q-S1 has cost 250€ with several lenses, slightly used. By selling of additional items my Q-kit still is very affordable. I haven't looked recently, but a while ago extensive Q kits went for very little money on ebay germany.
Bob (from Norderstedt, near Hamburg)
For you photography a lens with more than the 06s 45mm would be a great addition. Also a weak achromatic closeup lens would be nice for macro work.
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Forum: Pentax Q
10-26-2016, 09:10 AM
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Hi,
just before my summer holiday I made a 40,5mm fitting for an achromatic close up lens intended for a 1980s Sigma 80-200 zoom.
Here is one of the images I made with it. It is a 100% crop but compressed a bit more for small file size.
Bob
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Forum: Pentax Q
10-18-2016, 09:56 AM
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I live in Germany and here the temperatures typically range from -15 to 30 °C.
Our house is old but well insulated and we do our heating to maybe 40% with a wood stove.
On of my many interests are vintage chain saws. This year we got very big wood, about 90cm silver maple. I had to put my biggest saw in action: A Dolmar CC from ca. 1970.
The bar is not original, it is a japanese "porn"-bar.:lol:
The wood splits like hard rubber, so lots of sawing, lots of chips
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Forum: Pentax Q
10-18-2016, 09:41 AM
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I know this lens from use on a FED 2. My version (clean glass, no damages) was quite a bit softer than nearly all other 50mm lenses I have used. In addition there was a lot of haze in the pictures wich I can also find in your pictures. It roughly compared to my uncoated 1938 Kodak Retina I lens.
The Q ist the ultimative test instrument for lenses because it's pixel denisty is so high. The industar lens is, in my experience with just one sample, a lens that performs only to very low standards. You are inviting disappointment when you test the technical qualities of a so-so lens on this level.
Should you just junk this lens? No! But it isn't a lens for pictures where technical quality is needed in the first place. It is a lens that offers a dreamy 1950s look with misty haze, strong reaction on light sources and the look typical for lenses of the pre-computer era.
To find a companion for it that covers standard shots you should look for 50mm lenses of first class reputation.
In my experience the Q7/Q-S1 takes a bit sharper pictures than the original Q. I was not quite happy with the sharpness of my Q pictures and the Q7 is just what I need for most of my pictures.
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Forum: Pentax K-30 & K-50
06-11-2016, 01:23 PM
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The Pentax K-70 is annouced - I'm curious whether it still has the same shakey aperture mechanism.:confused:
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Forum: Pentax K-30 & K-50
05-31-2016, 12:33 AM
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I just looked into the K-30 / K-50 sub forum and it looks as if 25% of all activity there is centering around the aperture block failure! With so many cameras defective it probably won't take long to find someone to try and document the repair.
In the mean time Ricoh/Pentax are hopefully finishing their financial and technical planning for a full size call back. It would be quite a marketing move to show the whole market, that there ist at least one company that really stands behind it's product, even if its reacting a bit slow.
Probably in won't be long before the first frustrated buyers will start to think about handing in the broken cameras through the closed windows at Pentax head quarter.:rolleyes:
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Forum: Pentax K-30 & K-50
05-29-2016, 11:54 AM
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Since the K-30 has no problem according to Pentax no lubricant has to be used - so much is clear!
Using lubricants in production environments is quite costly. You have to apply the right volume to the right place and make no mess. So it is in fact not the best design to rely on lubricants in this application. Lubricants are also affected very much by temperature.
The whole amount of lubricants in a classic slr is probably less than 1 mm³.
I'm a mechanical engineer an am used to apply oil and grease in generous amounts. Before I tackle a camera repair, I have to lock away my grease gun. The key has a bad taste and is difficult to swallow.:D
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Forum: Pentax K-30 & K-50
05-29-2016, 05:45 AM
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In camera repair oils and greases are generally only used in homeopathic doses. The quicker the parts move, the more drag you add with the lubicants. The timing gears of shutters are lubricated by washing them with lighter fluid and fine graphite. The slower running bearings may get an additional screw driver tip wetted with light sewing machine oil. The film transport gears are nearly the only parts that are lightly greased. A drop of oil is much to much in all camera repair appications. You put a drop of oil on a surface, dip a small screw driver lightly with the tip in it and touch the bearing that has to be oiled. The quickest way to ruin a camera is a quick spray with WD 40. WD 40 is bad anyway because it doesn't lubricate well and gums up with time. The oil should be acid free to minimize gumming up.
I haven't seen the defective K-30 parts myself. I would guess that bigger surfaces are involved and oiling might lead to too much drag.
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Forum: Pentax K-30 & K-50
05-28-2016, 08:27 AM
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Hello Niceshot,
thank you for posting the link to the manual. 13$ is absolutely ok, you can't expect to get everything for free. Is it the original Pentax manual? I would have thought that they restrict the sale to their dealers and service companies and sell it directly to them.
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Forum: Pentax K-30 & K-50
05-27-2016, 11:28 PM
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It's great to see you working on dslr repair solutions. I think that about 50% of all defective cameras could be repaired by the informed amateur becuse they are not completely worn out or need parts but only suffer from a loosend screw or a soldered wire that broke of. The problem is the "...informed amateur..". There is really little information available on camara repair and so everybody has to start at zero, which is not an option for most people. Cameras have always been expensive and most people tend to just put a broken camera in the cupboard in the unrealistic hope that maybe someday a wonder might happen and it might work again. In reality camera technology develops quickly and you either get in running again now or never. Since this little needle file problem of a K-30 is able to render a great camera worthless there is really a big motivation to develop repair solutions and the risk is zero (apart form the condensator...). It is important to document them, to make others able to evaluate wheter the repair is feasible for them, and to store the information so that it can be accessed.
I especially like the international cooperation that has lead to this thread: I'm a German, the Russians have done great research work, and I'm sure you here will have a clarified and documented repair solution in English language ready soon. It is so much better to look what can be done for another than against another. :D
Now we only need somebody with a broken K-30 / K-50 and a couple of screw drivers to get ahead.
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Forum: Pentax K-30 & K-50
05-27-2016, 03:01 AM
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Hello Niceshot,
your work on your camera will be a very useful step ahead in the research of this problem. What is missing right now are detail pictures and measurements of the parts that cause the failure.
If you've got a second camera it would be great if you instal a bright no-glare lighting and do your best to get pictures that show the parts before and after your repair. If you've got a caliper or micrometer, it would be great to start a collection of measurements of these parts. Possibly we can identify problematic parts just by measuring their mechanical dimensions and have a recipe for the repair. I have all the measuring and photographic tools, but I'm not too keen to open my camera right now, since it still works.
In the end we might develop an adjustment process equal to the setting of the points of an igniton system. Maybe these Pentax-breakdowns are not a defect at all but a feature to have the determined users develop the same relationship to their camera that drivers of oil-leaking old british motor cycles have.:D
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Forum: Pentax K-30 & K-50
05-27-2016, 12:28 AM
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Thank you, IgorZ and THoog for you work on the repair solution.
I did some repair work on classic cameras and from that experience would avoid oil or grease at this coil. What might be of use is graphite powder, but it would have to be the finely ground variety and used in very small amount. My boys had detective kits when they were small and included was a bottle of very fine graphite powder. I had to confiscate this anyway :hmm: so why not put it to good use....
I can imagine that the proper shape and contact geometry of the parts depend on the residual magnetism of the individual part. This build up of residual magnetism may also be a cause for the variations of the units. I'm often astonished why some screwdrivers delelp magnetism, and others don't. The mechanisms will be checked successfully during manufacture, but the build up of magnetism will be different from unit to unit.
The pictures of the older cameras show, that it probably isn't a major design fault but a design that depends on a level of production quality, that they can't reliably maintain. What is a bit unnervig: They already had occasional problems with the K-x and K-r. In this case I would have expected of Pentax to adjust the design to tolerate the production quality available at this price point and to install a wide safety margin.
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Forum: Pentax K-30 & K-50
05-26-2016, 02:27 AM
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As a customer I expect a product to be capable for it's intended use. I am aware that products have a limited lifetime and that this lifetime ends when it is worn or or one component breaks down due to wear. The K30 / 50 has a serial error that renders a high percentage of examples useless even if they are only mildly used. In this case I would expect a manufacturer to offer a free repair outside of the guarantee period. When I'm dealing with people I have no problems when make mistakes, but my trust in them depends on wheter they admit them and do their part to correct them. Would you buy a used car from a neighbour who has acted like Pentax with the K30 / 50 affair in the past? I would not.
There is another disadvantage when a compay acts like Pentax: The dealers will have many conversations with unhappy and well informed customers. If they have less trouble with other manufacturer's products they will likely focus more on selling these brands and think about kicking Pentax out of their product range. This is nothing I would risk if I were a niche manufacturer like Pentax.
I would like that this thread moves back to the repair solution and not become a Pentax-bashing thread. I'm sure that somebody has a russian speaking technical minded friend or colleague who might be able to clarify this. Vodka might be the right incentive! :D
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Forum: Pentax K-30 & K-50
05-25-2016, 01:06 AM
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I had the impression, that they talked about parts becoming permanently magnetic and sticking to their counterpart. Somewhere I remeber to have read that they changed the shape of the contacting parts so that the residing magnetism would not be able to make the parts stick together. If nobody here is able to improve the google translation, we might try to contact the russian researchers and ask for help. Though I can't read their language, it is clear that they did a great job. They not only repaired their camera and went on with their other projects, they took the time to document the solution. I think I should thank them since this has been really nice of them.
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Forum: Pentax K-30 & K-50
05-24-2016, 10:16 AM
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As far as I understood, the cause of the failure is an electromagnetic actuator that develops a resident magnetism and starts to stick. Since the google-translation is somewhat creative I didn't really understand what in this long thread was just speculation or a test, and what is part of the repair solution.
My own K-30 ist still working, but I hate to take a camera system to important shooting situations, when the camera body is likely to fail. Hopefully the russian documentation of the research and repair solution will sooner or later lead to a permanent and cheap remedy. Mabe the Russians have offered what Pentax is declining their customers.
The untrustworthy way Pentax is coping with their K-30/50 serial error has cost them my sympathy and I don't have any special preference for Pentax products any more. For the moment I won't invest any more money in Pentax lenses and have an occasional look around.
Bob
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Forum: Pentax K-30 & K-50
05-24-2016, 06:01 AM
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Hi together,
our colleages from the russian Pentax forum have worked on the aperture block failure problem and semm to have found an explanation for the cause of the failure and have documented the repair. Only problem: I don't speak Russian and google translator is not much better. So we need a russian speaker or somebody wth a better translation software to understand the details of the repair approach. Here is the link to the repair documentation. Goggle translator at least gives a rough idea.
In Russian:
???????? ? ?30! - ?????? ?????-????? - ???????? 7
Anybody able to carry on from this point?
Bob
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Forum: Pentax Q
02-02-2015, 11:40 PM
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Has anybody compared the Pentax 110 lenses with the Pentax 06? Since I bought the 06 lens I rarely carried the 110 lenses with me for practical reasons.
In my stack of parts I found a tiny iris diafragm that just fits perfectly into the 110=>Q adapter. I can't name a source for this part though.
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Forum: Pentax Q
02-02-2015, 10:59 PM
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Here I show left upper corner and center crops of Q+03 lens vs. Q7+03 lens, both from the JPEGS staight out of cam. The Q7 image looks contrastier and has more resolution. For general use I always found the Q images to lack a little bit of clarity. So I'm quite happy with the improvement offered by the Q7.
When using the third party raw converter the image quality stays on a perfectly usable level right to the border of the image circle - amazing.
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Forum: Pentax Q
01-26-2015, 12:07 PM
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Hi Scott,
your approach again is completely different! As long as you can control the exposure you've got a responsive camera as well as a good sharpness/noise product. I will give it a try with the software I have!
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Forum: Pentax Q
01-26-2015, 12:09 AM
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Michaelina2, could you give me a hint where the obvious to you flaws in my testing procedure are to be found?
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Forum: Pentax Q
01-26-2015, 12:02 AM
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I've played around a bit with different raw converters but still prefer a good JPG staight out of cam. My impression was that with properly exposed images taken under normal lighting conditions I don't gain much by using RAW format, but I have to cope with a lagging camera and higher data volume.
I've got only a cheap notebook computer. With this screen it is difficult to assess white balance and exposure so I can't really use the main advantage of RAW processing.
That was the reason for me to test the JPEG settings of the Q7.
Where I found the RAW+ setting useful was when using the Qs built in color filters. From the RAW I could develop e.g. a colour version of an image taken in bold b/w mode. I'm not shure if colour filters where already available in RAW+ format with the original Q.
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Forum: Pentax Q
01-25-2015, 10:54 AM
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Obvious differences between 01 and 02 lenses are maximum f-stop and size. Pacerr, have you found differences in the look of the images that you include when choosing between these lenses?
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