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Forum: Pentax SLR Lens Discussion
08-12-2019, 04:02 AM
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You probably set the focus limiter by accident.
Change the Focus Range setting to "Full".
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Forum: Troubleshooting and Beginner Help
12-15-2016, 09:21 PM
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Perhaps Adam can create an FAQ page and a prominent link on the home page.
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Forum: Pentax KP
01-25-2017, 11:44 PM
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Forum: Pentax SLR Lens Discussion
11-07-2016, 05:42 PM
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I generally don't recommend people to disassemble a lens unless they have the appropriate skill and knowledge, but adjusting infinity focus should be easy enough for most.
The M28/3.5 shares the same basic construction principle as M50/1.4 so just follow the instructions for that lens, which are readily available on the web.
Quick guide:
1.) Remove name ring with rubber stopper, etc. You really need to be careful at this step. Using the wrong size stopper can scratch the lens if it has grit and dirt on it. Also, it can be very difficult to remove if someone has used a thread locker previously or the filter attachment ring is out of shape.
2.) Removing the name ring will reveal three screws which when unscrewed will let you remove the filter attachment ring.
3.) Removing the filter attachment ring will reveal further three screws that you loosen to adjust the infinity focus.
The screws involved are JIS +00 standard and use of appropriate screwdriver is recommended.
When everything goes well, it's an easy repair, However, if you come across problem like stubborn screws then this is when your knowledge and skill is required so that you don't end up stripping the head.
Every lens repair comes with risks so proceed at your own decision.
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Forum: Pentax SLR Lens Discussion
10-30-2016, 05:22 AM
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The ring inside the filter thread holds the front element. The filter mounting ring is threaded and is held in place by a single small grub screw accessible from the outside. You willl then see the three screws that adjust the focus but you can't quite reach them with a screwdriver. Removing the name ring then gives access to the screws as per K50/1.4, M50/1.4 and M50/1.7.
The K and A series 50/1.2 have slightly different construction to above mentioned lenses.
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Forum: Pentax SLR Lens Discussion
10-30-2016, 04:21 AM
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With the A50/1.4 lens, the ring with the name engraved on it is NOT threaded.
You first need to remove the rubber focus grip and then you'll see three holes. You then push a rod or screwdriver in the hole to release the catch. Be careful that you don't push too hard as the ring is made from plastic and you can easily break the catch.
It would appear that someone has taken the lens apart previously and re-assembled it without any regard for its proper operation. I'd be worried about the internal state of this lens. Why was the lens dis-assembled in the first place? It's not normal for a lens to shift the infinity focus so much under regular use.
Before you start disassembling the lens, check to make sure there are no other surprises like fungus or clouding by looking through the lens and making careful observations. If you discover something amiss that was not mentioned by the seller, then I suggest you contact him/her and have a discussion as to what to do. Once you start tampering with the lens, you've pretty much accepted the lens as is and returning the lens for refund would be questionable as the item is now not in same condition as it was shipped.
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Forum: Repairs and Warranty Service
07-18-2016, 08:52 PM
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The front group (it's a cemented pair) on this lens can be easily accessed by removing the retaining ring. However, you'd be best advised to get a proper lens spanner for removal of the ring as in most case for this lens, it's screwed in fairly tightly. One slip and you're likely to do some damage.
Having experience in both as a computer technician (over 25 years) and lens repairer (last 5 years), I can tell you that working with lenses require much more dexterity, care and patience. You really can't compare both. They are two totally different fields. :-)
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Forum: Pentax SLR Lens Discussion
09-18-2013, 04:08 AM
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The K50/1.2 is constructed differently from K or M 50/1.4 lenses. You will not be able to unscrew the dress ring (the one with writing on it) until you remove the ring with filter thread first. To remove the ring with filter thread, you first need to unscrew the ring that sits just above where the rubber grip ends.
1.) Remove the rubber grip. Use a thin piece of wood or plastic to gently lift the rubber away from the barrel and go all the way around.
2.) Use a sheet of rubber or rubber gloves to turn the top part of the ring (the part with silver coloured ring on it). It can be difficult to remove if thread locker has been used.
3.) You should now see three screws holding the ring with filter thread. Unscrew the three screws to remove.
4.) You should now be able to access all the front elements.
5.) To access the rear group, remove the mounting flange and then unscrew the rear element assembly.
This lens is prone to element separation and clouding of the cemented pair that is located at fourth group from the front, just behind the aperture diaphragm. To access this cemented pair, you need to remove the aperture assembly, held in place by 5 (or was it 6?) screws. If you do decide to remove the assembly, you should carefully mark the orientation beforehand as it controls the size of the aperture and thus the exposure.
Good luck!
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Forum: Pentax K-3 & K-3 II
02-08-2014, 12:25 AM
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Now someone needs to come up with an elegant way to attach your smartphone to the K-3 to be used as a tilt and swivel screen. :-)
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Forum: Troubleshooting and Beginner Help
02-10-2014, 07:26 PM
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I'm afraid I have to disagree with the lens separation theory.
It looks more like residue left by over-zealous application of lens cleaning fluid that has seeped in and under the front element.
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Forum: Pentax SLR Lens Discussion
02-03-2014, 06:16 PM
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One more thing regarding fungus.
There are so many stories, myths, hear-says, etc. floating about the web that it's hard to tell what the actual truth is.
From MY experience (I've been repairing lenses for a few years now, but of course my opinions could be totally wrong) the lens fungus has not had any detrimental health effects on me so I assume they are safe to humans in the small doses that one comes across in handling infected lenses. Whilst fungus spores exist everywhere, the specific type that affects lenses (more specifically, the type that likes to feast on the organic residue on the lens) may not be so common. How easily these spores gets transported from one lens to another is unknown. Once the fungus has been killed off by fungicide, UV radiation, etc. it should not grow any further (well, it's dead). To avoid growth of fungus, always store your lens in a cool, dry place with plenty of airflow. Cupboards, boxes, camera bags, or any other enclosed areas should be avoided. If you live in a humid climate, then use of a specialised dry box may be a good idea. Don't keep your lens stored away for long periods of time. Take it out regularly and use it to give it fresh air.
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Forum: Pentax SLR Lens Discussion
01-17-2014, 09:18 PM
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Can you observe any evidence of the lens being previously opened for service? (e.g. tool marks on screw heads, retaining rings, etc.)
If so, it's possible that one or more of the element has been reversed when re-assembled.
If there's no evidence of tampering, then it could be lens separation of one of the internal group. Some separation is hard to detect unless you look at it directly and you may not notice it if you just look through the lens.
Also, check to see if any part of the lens is loose or has some wobbliness. If you grab hold of the front most part of the lens, does it wobble or move slightly front and back? Old lenses like this, especially zoom lenses, will tend to have some loosened screws and will need to have them re-tightened.
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Forum: Troubleshooting and Beginner Help
01-08-2014, 06:03 PM
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Hi Carl,
I believe I'm the one that sold you the lens.
I'm sorry to hear that you're experiencing issues with the lens.
I can assure you that I did a complete test of the lens before I listed it for sale on eBay. All the lenses I sell go through a complete check when I purchase them and I clean and repair where necessary. I then adjust the infinity focus and test the exposure after re-assembly.
Now, having said that, there is always a possibility that I missed something as I'm only human and make mistakes now and then. If after going through the checks that other forum members have suggested and you still find the lens not functioning properly, please return it and I will give you a full refund including the return postage.
Best regards,
Tom
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Forum: Pentax K-3 & K-3 II
10-11-2013, 01:51 AM
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Here's the translation:
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Forum: Troubleshooting and Beginner Help
09-23-2013, 04:56 PM
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As an alternative to using screws, I have successfully repaired this type of damage in the following way:
1.) Cut a slot where the tab used to be.
2.) Glue a small piece of plastic.
3.) Shape the added plastic with a small file.
The trick, whether you use screws or follow my method, is that you need to make sure that the new tabs align perfectly with the grooves so that the assembly will slide smoothly.
To re-attach the front assembly, you need to first of all loosen the lens groups from the housing.
1.) Remove the dress ring / bezel on the front by gently lifting the ring with a small precision screwdriver. Be very careful not to slip and scratch the lens. For safety, you may want to use non metallic tool by crafting a wood or plastic stick. The ring is held in place by three plastic tabs and just clips on and off.
2.) You will now see four screws holding the lens group to the housing. Just loosening the screws is enough. No need to remove them.
3.) The lens group should now turn freely from the housing.
4.) Zoom the lens in to 70mm position.
5.) You should now be able re-insert the housing without too much trouble. Make sure the tabs are aligned properly to the grooves.
6.) Turn the lens group so that it engages the focus helicoid.
7.) Now, you will need to adjust for infinity focus. Set the focus ring to infinity and turn the lens group either clockwise or anti-clockwise to achieve correct focus. When set, tighten the four screws without moving the focus setting.
Good luck!
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Forum: Troubleshooting and Beginner Help
07-11-2013, 04:11 PM
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The ring with the focus distance scale is the actual focusing ring. There are three screws that hold it in place. To access the screws, you first need to remove the dress/vanity ring (the ring that has "smc Pentax-M 1:2.8 28mm" etc,) written on it. However, this will be very difficult to do in your case as the dent on the filter thread will prevent the ring from unscrewing. As the poster above has said, you'll need to get the dent straightened out first, without destroying the thread. Normally, the dress ring can be removed using a rubber bung.
Trying to straighten out the filter thread ring is nearly impossible without causing damage to the actual thread. If you're not worried about the external looks of the lens and just want to use it, you can use a small power tool such as Dremel, to cut out the affected area. After completion of the repair, you can always attach a filter to the lens and the cutout will be less noticeable. You can also go further by filling the affected area with epoxy or putty, then sand and paint.
There are few tricks to removing a stuck screw. The first rule is to use a CORRECTLY fitting driver and never use more force than necessary. If you feel the head starting to strip, STOP. Secondly, you can try dissolving the thread lock glue with acetone. Use a cotton swab to carefully seep the solvent into the thread, wait a few minutes and then try unscrewing. Thirdly, use some heat to weaken the glue. You can use either a soldering iron or a small gas blow torch for this purpose. BE VERY CAREFUL not to get the solvent or heat anywhere near plastic parts. For instance, the rear lens baffle is made from plastic, so you'll want to remove this part first before attempting to remove the screws holdling the lens mounting flange. Another WARNING. Acetone is extremely flammable. Do not use acetone when you have any heat source, such as soldering iron or source of open flame near by.
***DISCLAIMER***
I will not be responsible for any damage or injury that may occur by you attempting to follow the above instructions.
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Forum: Troubleshooting and Beginner Help
06-06-2013, 04:31 AM
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Just use some rubber glue to stick it back on or use some thin, double-sided tape. No need to spend $70.
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Forum: Troubleshooting and Beginner Help
10-19-2012, 05:09 PM
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I've repaired quite a few of these lenses.
From your description, it does sound as if something is loose inside.
Did this happen all of a sudden or did you purchase the lens second hand with this problem? If it's the latter, then I suggest that you ask for a refund.
If you want to attempt a repair yourself, then you need to remove the rubber focus grip first to get at the screws to undo the assembly and proceed from there. Be warned, however, that zoom lenses are fairly complex in design and not easy to fix if you have no experience. At the very least, you will need to tighten whichever screws that are loose and adjust for infinity focus. Without actually looking at the lens in hand, it's impossible for me to give you a step by step guide, so I apologise for that.
Good luck!
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Forum: Sold Items
10-09-2010, 06:22 PM
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PentaxForums.com Marketplace Listing
Item for Sale
Pentax F 1.7x AF Adapter (Mint)
Asking Price
US$335
Item Location
Tokyo, Japan
Item Description
Pentax F 1.7x AF Adapter
I have 4 available for immediate shipment.
Item condition:
- Brand new, unused.
I would rate the condition of this converter as mint. This item is un-opened box, never used. This item comes with open warranty certificate, but I'm not sure if Pentax warranty is transferable from the original owner (me). For obvious reasons, I'm unable to supply the original purchase receipt. It would be best to assume that this item has no manufacturer's warranty. I am, however, willing to offer a 30 day money back warranty in the unlikely event that something goes wrong.
Item description:
This converter is suitable for all digital and 35mm film SLR cameras, which has a Pentax K-mount.
This adapter needs no introduction. If you're looking at this listing, you should know all the details already. However, to be fair to the newbies, I will state that this adapter not only works as a 1.7x teleconverter, but it also adapts an older manual focus lens into an autofocus lens. So, in effect, your 50mm f1.4 manual focus lens becomes an 85mm f2.5 autofocus lens!
Other included items:
- This converter comes complete with both front and rear caps, soft pouch, instruction manual (Japanese), warranty certificate (see note above), and box as per original package.
See picture below.
Images:
Click on images for a larger view.
Complete package
Payment method:
- I can only accept payment via PayPal. Please complete your payment process as promptly as possible to avoid delays in shipping.
Postage and handling:
- Item will ship from Japan via EMS (Express Mail Service), usually within 2 business days after receipt of payment.
- Item should arrive at your destination in 5~10 days after despatch. However, this is an estimate only and may vary considerably depending on many circumstances.
- I can provide tracking number and web address to check the progress of your parcel.
- Item will be shipped to your PayPal registered address only.
- Insurance is included in the postage.
Custom duties and taxes:
- Any duties and taxes payable upon entry into your country is YOUR RESPONSIBILITY.
- Please research your country's laws and regulations carefully before buying.
Returns policy:
- 30 day money back warranty. Usual policy applies. (e.g. Does not cover accidental damage, abuse, etc.)
- All returns must be pre-approved and packaged properly.
Are you the original owner of the item being sold?
Yes
Are you selling or trading this item?
Selling
Item Condition (Key)
New
Shipping Destinations
Worldwide
Shipping Charge
US$22 - US, Canada, Australia. Please enquire for others.
Shipping Services
EMS (Express Mail Service)
Accepted Payment Types
PayPal
Return Policy & Additional Details
Please refer above for full details.
Please send me a private message if interested in the item!
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