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5 Great Pentax KM Lenses

´╗┐The Pentax KM is a great 35mm film single lens reflex (SLR) camera. This article will go over the 5 best lenses for the Pentax KM, plus a selection of alternative options.

This is the list of the 5 best lenses for the KM:

  1. Kit Lens - SMC Pentax-M 50mm f/1.7
  2. Wide Angle Lens - SMC Pentax-M 28mm f/2.8
  3. Portrait Lens - SMC Pentax 135mm f/2.5
  4. Zoom Lens - Vivitar Series 1 28-90mm f/2.8-3.5
  5. Macro Lens - SMC Pentax 100mm f/4 Macro

The best Pentax K mount lenses are separated by type of photography and price range. There are a number proposed choices to choose that have a wide range of prices ideal for the value of the camera.

Standard Focal Length Lenses

The following is an assortment of 50mm focal lengths that you can use with the KM. When the camera was being sold as new, there was quite often a offer available to buy a 50mm lens with the camera as a kit.

The 50mm is regarded as a standard lens due to the fact that the angle of view is close to what people see with their eyes.

SMC Pentax-M 50mm f/1.7

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SMC Pentax-M 50mm f/1.7
  • “Kit” lens for the KM.
  • Awesome value.
  • Light, small, and compact.
  • 49mm filter threads.
Check prices on: Amazon, eBay, Adorama or KEH

If you do not currently have it, a capable first lens to buy is the SMC Pentax-M 50mm f/1.7. The 50mm f1.7 is easy to find, is low-priced, has very good photo quality, light, and portable . It is the most widely used lens on the camera.

{You can also buy the next version, the SMC Pentax-A 50mm f/1.7|The next version, the SMC Pentax-A 50mm f/1.7, is also a good buy}.

SMC Pentax-M 50mm f/1.4

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SMC Pentax-M 50mm f/1.4
  • Exceptional optics.
  • Improved performance from optical multi-coatings.
  • Easy to find.
  • Comparatively inexpensive.
Check prices on: Amazon, eBay, Adorama or KEH

The SMC Pentax-M 50mm f/1.4 is nearly a stop faster than the f/1.7, at the added burden of increased weight and size. Expect to pay more than you would for an f/1.7 or f/2 lens. The earlier version, SMC Pentax, and later version, SMC Pentax-A, will both work with the KM.

SMC Pentax 50mm f/1.2

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SMC Pentax 50mm f/1.2
Check prices on: eBay, Adorama or KEH

Just like all of the other camera companies, Pentax developed a fast 50mm lens. The resulting SMC Pentax 50mm f/1.2 is a quite large, fast, and high-priced piece of glass.

The lens can be tricky to find because it will work on Pentax DSLRs so the appeal extends beyond usage with 35mm film cameras. If you want to find one you will need to check and have a look at what is offered over weeks or months.

Wide Angles

SMC Pentax-M 28mm f/2.8

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SMC Pentax-M 28mm f/2.8
  • Great combination with a 50mm lens.
  • Super Multi Coating (SMC) to improve performance.
  • Many copies can be found.
  • Relatively cheap.
Check prices on: Amazon, eBay, Adorama or KEH

The SMC Pentax-M 28mm f/2.8 isn’t the best option. In fact, many do not even consider it to be a wide angle lens. Having said that, it is a lot less expensive than any wider alternative.

There are plenty of wider focal lengths to choose from, but they are possibly significantly higher priced or third-party choices have obvious barrel distortion. Additionally, it is easy to see chromatic aberrations and other optical defects in third-party offerings.

Alternatives

When it comes to pricing, the correlation is easy to understand. As the field of view gets wider, the lens will cost more. Lenses with large apertures will also be higher priced.

Also, keep in mind that vintage wide angle lenses don’t have all the corrections that modern wide angle lenses have. The issue you’re most likely to see with vintage wide angles will be noticeable barrel distortion.

  • SMC Pentax-M 20mm f/4
  • SMC Pentax-M 28mm f/2
  • SMC Pentax 18mm f/3.5
  • SMC Pentax 24mm f/2.8

Portrait & Telephoto Lenses

SMC Pentax 135mm f/2.5

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SMC Pentax 135mm f/2.5
  • 85mm substitute.
  • Excellent value.
  • Relatively inexpensive.
  • Widely available.
Check prices on: Amazon, eBay or KEH

85mm focal length lenses weren’t as frequently used as they are today in comparison to when the KM was initially introduced back in DDATE. On account of being cheaper, 100mm and 135mm focal lengths were more frequently used.

The difference in price can be seen when you view what’s available.

More Options

There are plently of telephoto lenses to select from. Focal lengths longer than 135mm and 85mm lenses are going to be higher priced.

  • SMC Pentax 85mm f/1.8
  • SMC Pentax 85mm f/2.2 Soft
  • SMC Pentax 105mm f/2.8
  • SMC Pentax 120mm f/2.8

Zoom Lenses

Prior to the introduction of autofocus, in the early 1980s, there were a small number of lenses manufactured by third-party manufacturers that performed better than what Pentax was offering.

Quite a few of these top performers were released under the Vivitar brand. Zooms featuring the Vivitar Series 1 branding is going to have the best optics you will see from a vintage zoom.

Sadly, obtaining one of these lenses in acceptable condition can be rather hard. Beyond that, no older zoom offers outstanding performance. If you find a copy for sale that is inexpensive enough, it may be worth buying.

Vivitar Series 1 28-90mm f/2.8-3.5

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Vivitar Series 1 28-90mm f/2.8-3.5
Check prices on: Amazon, eBay or KEH

More Options

Here are some more alternatives that you can check out if you want to have a zoom for your KM. None of them are going to be incredible, and you would likely be better off purchasing a couple of Prime lenses.

  • SMC Pentax 85-210mm f/3.5
  • Vivitar Series 1 70-210mm f/3.5
  • SMC Pentax 45-125mm f/4

Pentax Macro Lenses

Macro lens choices for the Pentax KM have problems with availability. The available supply of Pentax K mount options is tiny, which increases prices higher than you’ll pay for comparable Nikon F mount or Canon FD mount lenses.

SMC Pentax 100mm f/4 Macro

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SMC Pentax 100mm f/4 Macro
  • Ideal focal length for 1x magnification.
  • Widely available.
  • Mediocre value.
Check prices on: Amazon, eBay or KEH

A few people online have experienced balsam separation of the front doublet. This is worrying because even just a little separation will spread over time and eventually make it unusable. If you think you see balsam separation, avoid that lens and continue shopping.

Vivitar 55mm f/2.8 Macro

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Vivitar 55mm f/2.8 Macro
  • The second best vintage macro lens I’ve used.
  • An outstanding lens for close-up photography.
  • Can achieve life-size magnification without needing an extension tube.
Check prices on: eBay, Adorama or KEH

The best vintange macro lens I’ve owned, the 90mm Vivitar, was manufactured for a variety of mounts. Unfortunately, it will be difficult to obtain a copy that has a Pentax K mount.

The Vivitar 55mm is the best vintage standard focal length macro lens I have used. Take into account that it does have a smaller working distance compared to the 90mm. It is good for table top and close-up photography, but it is not the ideal choice if you would like to capture macro photos at 1x magnification.

Both of the Vivitar macro lenses were manufactured by Komine and were released under several different brand names. If you decide to look for one also search under the Rokunar, Spiratone, Quantaray, Elicar, and Panagor brand names.

There is a Vivitar 90mm Macro Review and a [/vivitar-55mm-f-2-8-macro-lens-review](Vivitar 55mm Macro Review).

For shooting photos at macro magnification (1x), focal lengths in the 90mm-105mm range will be the ideal choice. You’ll have a big enough working distance to allow the use of flash, while avoiding substantial weight and excessive costs that come with longer focal lengths.

More Alternatives

Used Pentax Lens Prices

Demand and supply will set the price of vintage lenses. Over the last several years, film photography has expanded in popularity, which has increased prices.

Extra upwards pricing pressure is produced by Pentax DSLR users purchasing and collecting lenses. Third party manufactures generally do not make anything for the K-mount, unlike the Canon EF or Nikon F mounts.

Economic conditions are continuously changing, and sudden events can lead to price movements. Even so, the relative prices between choices should stay similar.

Taking a look at several sites is a smart way to get reliable pricing information. If you’re fortunate enough to discover a terrific deal, purchase it due to the fact that the best deals tend not to last long.

What Lens Mount Does the Pentax KM Use?

The Pentax KM uses the Pentax K lens mount.

Released in 1975, the Pentax K mount is still being used in cameras today. It replaced the M42 screw mount that was used in previous cameras such as the Asahi Pentax Spotmatic. Over time improvements have been made to add autofocus, CPU contacts, metering information, and electronically controlled apertures.

Provided that a lens has a physical aperture ring, it will be compatible with Pentax film cameras. Keep in mind, it isn’t a good idea to waste money on pricey features that are not going to be be useable. An exception would be if you also use Pentax DSLRs.

It’s also possible to use the previous M42 mount lenses by using an adapter. The older Takumar lenses are the best to use in this situation. Having said that, I would not advise doing this as finding them without a tight focus ring can be difficult.

Lens Cap Size

The standard lens cap and filter ring thread diameter used on most manual focus Pentax K mount lenses is 49mm. They were originally sold with slip on caps, and not the more prevalent center-pinch design found today. Looking at what’s available, you’ll see not very many lenses sold with matching caps.

Keep in mind large front elements will need to use larger caps and filters.

The advantage of using a standard filter thread size is that you only need to own one filter set.

Pentax-M vs Pentax-A

Pentax-M and SMC Pentax lenses are made with a stop-down coupler which is built with a mechanical linkage to the camera. The stop-down coupler lets the camera to know the aperture is set to so the light meter is able to meter accurately without being required to use stop-down metering.

The Pentax-A series added the ability for the aperture in the lens to be set by the camera. Which means cameras that support the Pentax-A changes have the capability to do aperture priority and shutter priority modes.

However, due to the fact that that capability is not supported by the camera, it does not make financial sense to spend money on capabilities the camera is not able to use.

That’s it for advice on the best lenses for the KM. Here is further information that will provide you with more information about the camera can be found down below: