[Rainycity]

Hey yall, i recently just bought a pentax program plus. It came with few lens and they all fit except one. My question is, does this lens fit my program plus, or did the person i bought the camera from just include it with all the other lens?

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[kypfer]

It "should" fit, but with reservations.
The "sticking out" flange on the base of the lens may be too long and interfere with the camera. This can be cut down to size. As you have other lenses you can do a comparison.
Also, the lens has the infamous "Ricoh pin", at about 2 o'clock on your second picture, which can cause problems in some instances. Best disable it (glue it in) or remove it completely. There are other threads on this subject, if you do a search
Koboron lenses do have a reputation for good quality, so possibly worthwhile pursuing this, rather than discarding it out of hand.
Good luck

[aslyfox]

@Rainycity

welcome to the forums

You will find friendly members and a lot of knowledge here

although not a requirement, looking through the " articles " is a good idea

The Evolution of the Pentax K-mount
Technical Information and a Little Bit of History


. . . Third Party Variants of the K-mount
Pentax made the original "K" mount available for other camera manufacturers to adopt. The goal was to create a universal standard bayonet mount much like the M42 screw mount had been. Ricoh, Chinon, and others produced cameras and lenses with the "K" mount. Unfortunately, with the introduction of the "KA" mount, Pentax reversed the decision with the result that the other manufacturers either abandoned the "K" mount or developed their own, somewhat incompatible, enhancements. Several third party lens manufacturers produce or has produced lenses with a K-mount. There are no issues with current third party lenses in K-mount, but for older lenses there are two traps to watch out for:

The infamous "Ricoh pin". Where Pentax created the "KA" mount in order to support Program and Tv exposure automation, Ricoh had to create their own variant, which has a protruding pin placed in a somewhat unfortunate location, namely in the exact spot where Pentax years later placed the autofocus drive shaft. Such a Ricoh lens will get stuck when mounted on a Pentax autofocus body - the Ricoh pin will get lodged in the drive shaft and prevent the lens from being removed without deployment of finesse, patience and tools.

The other trap is the shield that protects the aperture stop down lever. The image to the left shows what the shield should look like and does look like on a genuine Pentax lens. Some older third party lenses have a much larger shield which prevents mounting the lens on a Pentax DSLR. Current third party lenses (Sigma, Tamron, Rokinon, etc.) have correctly shaped shields (or no shields) and pose no problem. . .

The Evolution of the Pentax K-mount - Articles and Tips | PentaxForums.com


as is looking at this section of the forums: Troubleshooting and Beginner Help - PentaxForums.com

[marcusBMG]

Kobori made lenses were prone to the aperture guard problem for a while, and the PK/AR mount is for ricoh too. This vivitar is also a kobori. See

https://www.pentaxforums.com/userreviews/showfull.php?product=536&bigimage=viv28-200-2.jpg

[THoog]

Neither the aperture guard nor the Ricoh pin should have any effect on a manual-focus film camera like the Program Plus. Can you give us more detail on how the lens does not mount? Does the bayonet not insert all the way, or at all?

[Rainycity]

Neither the aperture guard nor the Ricoh pin should have any effect on a manual-focus film camera like the Program Plus. Can you give us more detail on how the lens does not mount? Does the bayonet not insert all the way, or at all?

Hi i figured out the problem, being new to cameras i have basically zero knowledge on the subject. The problem was the camera came to me with a 35mm screw on adaptor and 3 screw on lenses. I assumed those were the normal lenses for the camera until i took a closer look online and found out that my camera looked a bit off. I have figured out what the problem is now i just have to figure out how to remove it since the tool that comes with the adaptor is not included. Thanks everyone for the help, im slowing learning the terminology and figuring things out one by one.

[THoog]

Hi i figured out the problem, being new to cameras i have basically zero knowledge on the subject. The problem was the camera came to me with a 35mm screw on adaptor and 3 screw on lenses. I assumed those were the normal lenses for the camera until i took a closer look online and found out that my camera looked a bit off. I have figured out what the problem is now i just have to figure out how to remove it since the tool that comes with the adaptor is not included. Thanks everyone for the help, im slowing learning the terminology and figuring things out one by one.

Glad you figured it out! If the adapter ring is a genuine Pentax, then (1) congratulations - those are highly prized, and (2) you should be able to remove it just by inserting a fingernail in the notch, pulling the locking spring away from the mount, and gently twisting counter-clockwise. If it isn't a genuine Pentax, you will probably need a tool, but a small screwdriver should work. Some of the cheap 3rd-party adapter rings are machined so badly that they are hard to remove even with the tool, and the locking spring is worse than useless. For those, I usually clean up the machining with a file, remove and discard the spring, and try to avoid twisting the lens out of the mount when focusing.

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Last edited by THoog; 02-28-2022 at 04:42 PM.