[stevebrot]

Another question is why cameras like the KM is about 200 grams heavier than ones like Program Plus? Is this related to how rugged they are?

Size, materials, construction, and technology. The KM is a fully mechanical camera and is the last step in the evolution of the Pentax Spotmatic. The design is well-proven and robust. While not large by standards of the day, it is somewhat bulkier and heavier than the compact SLRs of the late 1970s into the 1980s. The Program Plus and other A-series bodies are second-generation electronic cameras where most of the functions except for film transport are done using (then) state of the art technology. The construction of those cameras is solid, though they do have vulnerabilities common to all electrical/electronic devices. Conventional wisdom goes like this:

• The 1980s are generally considered to represent the high point of 35mm SLR development
• Cameras of that era have proven themselves to be robust and dependable
• Cameras of that era may be difficult to service due to the nature of how they are made and the unavailability of parts
• A good rule of thumb is that an 80s vintage camera in clean and working condition will likely continue to operate quite with only basic maintenance, though when it dies, it will be dead
• Some highly desirable professional models may be worth attempting expensive repairs, but most are not

The actual construction of 1980s vintage bodies is variable. Some are traditional metal exterior over metal chassis. Others are (mostly) polycarbonate exterior over metal and the remainder are polycarbonate exteriors over reinforced resin chassis. Almost all are both smaller and lighter than traditional SLRs. I don't know for sure where the Program Plus falls. Both it and the Super Program have metal chassis, but I am not sure if the exterior bits are metal.*


Steve

* This is sort of silly since I own the Super Program. My feeling has been that it has plastic top and bottom plates with a metal film door. Other forum members have reported metal top/bottom. I have no interest in carving either up to see.

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Last edited by stevebrot; 09-30-2016 at 06:17 PM.

[leekil]

I have a gouged Super Program where it is clearly plastic underneath the top metal panel. Though others seems to think there could have been two different top panels? The frame is metal, though.

---------- Post added 10-01-16 at 11:04 AM ----------

LR44 is an alkaline cell and is inferior for camera use, except in an emergency IMHO.

Do you see an issue with alkaline batteries, or just reduced life compared to silver oxide?

[gofour3]

Do you see an issue with alkaline batteries, or just reduced life compared to silver oxide?

If you have a brand new set of either they will function the same. It's only when the batteries get used that silver oxide are way better in the end, as they hold their 1.5 voltage longer.

Phil.

[stevebrot]

I have a gouged Super Program where it is clearly plastic underneath the top metal panel.

I did some Google work after I posted and found a reference that indicates the top/bottom plates are chromed plastic. That was my impression and your observation for at least our two cameras.


Steve

[signorsalvo]

K2, superb camera.

[ChrisPlatt]

There were some very interesting K-mount cameras made by other manufacturers.
My first K-mount camera was a Sears KS1000 (aka Ricoh XR-1s) body, and I have owned others.

However my advice always is to choose a Pentax simply because Pentax is the brand Eric Hendrickson repairs.
Eric's reliable and inexpensive service is a major reason I switched to and continue to use Pentax cameras.

Chris

[butangmucat]

There were some very interesting K-mount cameras made by other manufacturers.
My first K-mount camera was a Sears KS1000 (aka Ricoh XR-1s) body, and I have owned others.

However my advice always is to choose a Pentax simply because Pentax is the brand Eric Hendrickson repairs.
Eric's reliable and inexpensive service is a major reason I switched to and continue to use Pentax cameras.

Chris

I grabbed a Program Plus, but I wounder that will he actually repair a electro-mechanical camera?

---------- Post added 10-02-16 at 12:53 AM ----------

Size, materials, construction, and technology. The KM is a fully mechanical camera and is the last step in the evolution of the Pentax Spotmatic. The design is well-proven and robust. While not large by standards of the day, it is somewhat bulkier and heavier than the compact SLRs of the late 1970s into the 1980s. The Program Plus and other A-series bodies are second-generation electronic cameras where most of the functions except for film transport are done using (then) state of the art technology. The construction of those cameras is solid, though they do have vulnerabilities common to all electrical/electronic devices. Conventional wisdom goes like this:

• The 1980s are generally considered to represent the high point of 35mm SLR development
• Cameras of that era have proven themselves to be robust and dependable
• Cameras of that era may be difficult to service due to the nature of how they are made and the unavailability of parts
• A good rule of thumb is that an 80s vintage camera in clean and working condition will likely continue to operate quite with only basic maintenance, though when it dies, it will be dead
• Some highly desirable professional models may be worth attempting expensive repairs, but most are not

The actual construction of 1980s vintage bodies is variable. Some are traditional metal exterior over metal chassis. Others are (mostly) polycarbonate exterior over metal and the remainder are polycarbonate exteriors over reinforced resin chassis. Almost all are both smaller and lighter than traditional SLRs. I don't know for sure where the Program Plus falls. Both it and the Super Program have metal chassis, but I am not sure if the exterior bits are metal.*


Steve

* This is sort of silly since I own the Super Program. My feeling has been that it has plastic top and bottom plates with a metal film door. Other forum members have reported metal top/bottom. I have no interest in carving either up to see.

So any SLR that requires a battery to work is one of the 80s electro-mechanical cameras?

Edit: I picked up a Program Plus and a KM (because I had a little extra cash). My plan of action is to field test these two bodies and my Sears KSX-P, and eventually sell my least favorite of the KSX-P, KM, and Program Plus. Any input on this topic will be helpful, too. The KM came with a SMCK 55/2 and the Program Plus came with a SMCA 50/2, which one is better? The user review page suggested that the SMCK 55/2 is a rare glass, but I wounder if it is worth keeping when I also have a similar A lens.

Sincerely

---

Last edited by butangmucat; 10-02-2016 at 02:17 AM.

[stevebrot]

So any SLR that requires a battery to work is one of the 80s electro-mechanical cameras?

Any camera with a battery will have electrical components that may fail.

Any camera that requires a battery will be dependent on its electrical components.

I picked up a Program Plus and a KM (because I had a little extra cash). My plan of action is to field test these two bodies and my Sears KSX-P, and eventually sell my least favorite of the KSX-P, KM, and Program Plus.

Cool! All three have their strong points and are fun.

The KM came with a SMCK 55/2 and the Program Plus came with a SMCA 50/2, which one is better?

The K 55/2 is the better of the two optically (much better), though the A 50/2 is easier to use on your Super Program and Pentax dSLRs.

Edit: The K 55/2 is not particularly rare nor does it have any cult standing. It is optically identical to the K 55/1.8 and differs only in the maximum aperture for the iris mechanism. When new it was slightly cheaper than the 1/3 stop slower f/1.8 version. Both are based on the long-lived and excellent M42 55/1.8 Asahi Takumar variants dating back to the late 1950s.


Steve

[leekil]

If you have a brand new set of either they will function the same. It's only when the batteries get used that silver oxide are way better in the end, as they hold their 1.5 voltage longer.

And the effect will be what? Just a camera that won't work, or something else?

[gofour3]

And the effect will be what? Just a camera that won't work, or something else?

If the Alkaline batteries do not hold their voltage over time, then I guess the light meter would be affected.

I have only used the discontinued Mercury and now Silver Oxide batteries in my Pentax 35mm film bodies, so I have never experienced the gradual failure of an Alkaline battery.

Silver Oxide hold the voltage better till they just die.

Phil.

[monochrome]

If you decide to let the 55/2 go please send me a PM.

[stevebrot]

And the effect will be what? Just a camera that won't work, or something else?

The meter will not be accurate during the second half of the battery life. There is a reason why the camera user manual stipulates silver cells. Those maintain constant voltage for the entire battery life.


Steve

[Xmas]

The meter will not be accurate during the second half of the battery life. There is a reason why the camera user manual stipulates silver cells. Those maintain constant voltage for the entire battery life.


Steve

Many Pentax cameras pre and including K1000 series use differential circuits that operate ok (within 1/3 stop) bright to dark with any button cell types. Proviso low internal resistance, ie alkaline at end of life not repeatable, but ok if stuck on Sunday as are zinc hearing aid types which can weep but do last well in low temperatures, and will fit with generic rubber o ring or bit of cordage.

---------- Post added 10-07-16 at 11:28 AM ----------

If you decide to let the 55/2 go please send me a PM.

The early non SMC lenses have a different signature independent of optic correction. They are favoured by mono and slide shooters as well as digital types for adaptive contrast compression and 'pre' flashing of shadows.

Spent ages finding an auto-takamur...

[butangmucat]

Cool! All three have their strong points and are fun.

My Winder ME II arrived today, and now I can do some real train shooting with my Program Plus now. I however can't find a winder for KSX-P anywhere, I guess that body is out.

---------- Post added 10-07-16 at 11:10 PM ----------

My Soviet rangefinder cameras (Zorki 4K, FED-2, and Kiev 4A) all have yarn seals. That being said, all three have slide-off full removable backs. Yarn seems to work well for that application.



Caution that the thickness of that felt for the hinge seal is critical.

I appreciate the DIY approach, but while Jon Goodman still sells his most excellent custom kits with all materials in proper widths and thickness,* his product will remain my first choice when doing the seals. It also helps that I can't buy the materials for what he charges (~$10 USD, including postage).


Steve

* The strips for the rear seals are over-length and must be trimmed to size. This is done as a last step as they are laid in the slot. I use a pair of cuticle scissors. Jon usually includes one or two extra strips to allow for wastage.

Could you elaborate a bit about the yarn approach? My KM arrived with no light seals left so I have to DIY, I think.

---------- Post added 10-07-16 at 11:11 PM ----------

My Soviet rangefinder cameras (Zorki 4K, FED-2, and Kiev 4A) all have yarn seals. That being said, all three have slide-off full removable backs. Yarn seems to work well for that application.



Caution that the thickness of that felt for the hinge seal is critical.

I appreciate the DIY approach, but while Jon Goodman still sells his most excellent custom kits with all materials in proper widths and thickness,* his product will remain my first choice when doing the seals. It also helps that I can't buy the materials for what he charges (~$10 USD, including postage).


Steve

* The strips for the rear seals are over-length and must be trimmed to size. This is done as a last step as they are laid in the slot. I use a pair of cuticle scissors. Jon usually includes one or two extra strips to allow for wastage.

Could you elaborate a bit about the yarn approach? My KM arrived with no light seals left so I have to DIY, I think.

P.S. If I need to order from Mr. Goodman I just shoot him an E-mail?

[butangmucat]

Somehow Chinon solved it without the Contacts like Pentax or the Pin like Ricoh.

So I did some research on Nikon, which uses a similar mechanical stop-down lever for the camera to control the aperture. As I understand, Nikon pre-AI-s leses, just like pre-A Pentax lenses, don't have the linear diaphragm lever, and Nikon added this in their AI-s lenses. However certain Nikon film bodies can use AI lenses with P or Tv modes. Nikon achieved this by guessimate an exposure combination using open-aperture metering, and when the shutter is pressed, the meter is activated again after the lens is stopped down and takes a reading that "corrects" the stop-down process accordingly to work around the non-linear stop down movement. I assume Chinon might implemented their P mode in a similar way, at the cost of slightly higher shutter lag.

Cheers

Source: http://www.kenrockwell.com/nikon/nikortek.htm#ais

The "s" means that the actuation of the diaphragm was linearized with respect to the position of the automatic diaphragm pin. This is very important for AF cameras because they have have open-loop exposure control that depends on the aperture being exactly correct or else your exposure will be off. It is not important to manual focus cameras. (see "Aperture Calibration" below)

Some manual-focus, auto-exposure cameras like the FA use closed-loop exposure control. That means that they make the actual exposure measurement in the instant AFTER the lens stops down but before the mirror flips up, and means that they will automatically compensate for any inaccuracy in the lens diaphragm actuation.

Adding linearization to the actuation made it possible for these cameras to work a little more quickly when you pressed the shutter. It allowed the camera to get to the intended aperture a little faster, since it could guess pretty well where the diaphragm control pin needed to be and just go there, instead of having to release that pin a little more slowly while monitoring the light through the lens to arrive at the intended aperture by successive approximation.

All this happens in thousandths of a second, and I've never felt any speed difference on my FA between AI and AI-s lenses. The difference would be in the lag from when you pressed the shutter to when the film gets exposed, and it all seems pretty instantaneous to me.

Today some people think that AI-s lenses are required in order to get shutter-preferred (S) and program (P) modes on cameras like the FA. Nikon salespeople tried to suggest this casually as a ploy to get people to replace their AI lenses with new AI-s ones, and this myth still exists today.