5 Classic Pentax MX Lenses Every Photographer Will Love

´╗┐The Pentax MX is a great 35mm SLR when paired with the right lens. This page will cover the 5 best lenses for the Pentax MX, with a handful of alternative for different budgets.

In a hurry? The following is the list of the 5 best lenses for the MX:

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  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 categorized by type of photography and price level. There are a number recommended options to choose from that have a wide range of prices well suited considering the price of the Pentax MX.

The Pentax MX has a Pentax K lens mount.

Released in 1975, cameras currently being produced still use the Pentax K mount. It is a replacement for the M42 screw mount that was used in previous cameras like the Asahi Pentax Spotmatic. Over the years alterations have been made to add metering information, autofocus, electronically controlled apertures, and CPU contacts.

Provided that a lens has a physical aperture ring, it will be backward compatible with Pentax film cameras. Keep in mind, it is not a good idea to waste money on expensive features that can not be able to be used by the camera. The exception would be if you also own and use Pentax DSLRs.

It’s also possible to use the previous M42 lenses with an adapter. The older Takumar lenses will be best to use in this situation. Even so, I wouldn’t advise doing this as finding them without a tight focus ring can be frustrating.

SMC Pentax and Pentax-M lenses have a a stop-down coupler that provides a linkage to the camera. The stop-down coupler will allow the camera to know what the aperture is set to so that the light meter can meter properly without being required to use stop-down metering.

The Pentax-A series introduced the capability for the camera to control the aperture in the lens. Which means cameras that are compatible with the Pentax-A changes have the ability to do shutter priority and aperture priority modes.

Even so, seeing as that capability isn’t supported by the camera, it would not make sense to spend money on capabilities that the camera cannot use.

The standard filter ring thread and lens cap diameter used on the majority vintage manual focus Pentax K mount lenses is 49mm. Lenses were sold with slip on caps, and not the more common center-pinch type found today. If you shop at what’s available, you will discover a lack of matching lens caps being sold with lenses.

Bear in mind large front elements will need bigger filters and caps.

The advantage of using a standard thread size is that you only need just one set of filters.

Here is a range of 50mm focal lengths that you can use with the MX. When the camera was being sold as new, there was typically a discount available to buy a 50mm lens with the camera as a kit.

They are considered standard lenses due to the fact that the angle of view for the lens is close to what people see with their eyes.

SMC Pentax-M 50mm f/1.7 Standard Prime Lens
SMC Pentax-M 50mm f/1.7
  • “Kit” lens for the MX.
  • Fantastic value.
  • Light, small, and compact.
  • 49mm filter threads.

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If you don’t currently have it, a capable initial lens to get a hold of for the MX is the SMC Pentax-M 50mm f/1.7. The 50mm f1.7 is easy to find, is light, has terrific image quality, is affordable, and small . More photographs have been shot with this lens when compared to all other lenses.

{You can also purchase the second version, the SMC Pentax-A 50mm f/1.7|The 2nd version, the SMC Pentax-A 50mm f/1.7, is also a good buy}.

SMC Pentax-M 50mm f/1.4 Fast Prime Lens
SMC Pentax-M 50mm f/1.4
  • Exceptional optics.
  • Improved performance from optical multi-coatings.
  • Easy to find.
  • Comparatively affordable.

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The SMC Pentax-M 50mm f/1.4 is approximately a stop faster than the f/1.7, at the added cost of added size and weight. An f/1.7 or f/2 lens will cost more. The earlier version, SMC Pentax, and subsequent version, SMC Pentax-A, are both compatible with the MX.

SMC Pentax 50mm f/1.2
SMC Pentax 50mm f/1.2

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Similar to competing camera manufactures, Pentax released a very fast 50mm lens. The resulting SMC Pentax 50mm f/1.2 is a high-priced, fast, and big hunk of glass.

The lens can be challenging to get because it will work on Pentax DSLRs so the appeal includes more than usage with film cameras. If you want to get a copy you may need to check and track what’s available over weeks or months.

SMC Pentax-M 28mm f/2.8 Prime Wide Angle Lens
SMC Pentax-M 28mm f/2.8
  • Great combination with a 50mm lens.
  • Super Multi Coating (SMC) to improve performance.
  • Many copies are available.
  • Relatively cheap.

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Not the best option, the SMC Pentax-M 28mm f/2.8, is still a good choice. In fact, many may not even consider it a wide angle lens. Even so, it is noticeably less expensive when compared to any wider option.

There are many of wider focal lengths to consider, but they’re possibly significantly more expensive or third-party options have visible amounts of barrel distortion. Additionally, it is easy to see optical defects like chromatic aberrations in third-party offerings.

The rule of thumb for pricing is easy to understand. The wider the field of view, the more expensive the lens is going to be. Lenses with large apertures will also be more expensive.

Take into account, that these don’t have all the corrections that modern wide angle lenses have. The issue you are most likely to see with vintage wide angles will be apparent 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
SMC Pentax 135mm f/2.5 Telephoto Prime Portrait Lens
SMC Pentax 135mm f/2.5
  • 85mm substitute.
  • Excellent value.
  • Relatively inexpensive.
  • Widely available.

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85mm focal length lenses were not as frequently used as they are today in comparison to when the MX was first released back in 1976. 100mm or 135mm focal lengths were more widely used because of their lower cost.

The price difference is obvious when you view what’s available.

There are many telephoto lenses to select from. 85mm and focal lengths longer than 135mm will be expensive.

  • 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

Prior to the release of autofocus, in the 1980s, there were a few lenses manufactured by third-party brands that performed better than what Pentax was offering.

A large number of the best performers were released under the Vivitar brand. Any zoom that’s got the Vivitar Series 1 branding on it is going to have the best optics you’ll see from a vintage zoom lens.

Sadly, obtaining copies of these lenses in acceptable condition can be extremely challenging. Beyond that, no older zoom offers outstanding performance. If you find one available for purchase that is cheap enough, it might be worth picking up.

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

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Here are a few more options that you can consider if you need a zoom lens for your MX. None of them are going to be amazing, and you would likely be better off buying a couple of prime lenses instead.

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

Macro lens options for the Pentax MX suffer from problems with availability. The available supply of Pentax K mount choices is limited, which increases prices higher than you will pay for equivalent Nikon F mount or Canon FD mount options.

SMC Pentax 100mm f/4 Macro Lens
SMC Pentax 100mm f/4 Macro
  • Ideal focal length for 1x magnification.
  • Widely available.
  • Mediocre value.

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A small number of people online have run into balsam separation of the front doublet. This is worrying because even a little bit of separation will spread gradually and eventually make it unusable. If you think you see balsam separation, avoid that copy and keep shopping.

Vivitar 55mm f/2.8 Macro Lens
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.

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My favorite vintange macro lens I have used, the 90mm Vivitar, was made for a variety of mounts. However, it is tough to get a copy that features a Pentax K mount.

The Vivitar 55mm is my second favorite vintage macro lens. A noteworthy difference is that it does have a smaller working distance than the 90mm. It is excellent for close-up and table top photography, but it is not the best choice if you would like to capture macro images at life-sized magnification.

Both Vivitar macros were produced by Komine and were released under various brand names. If you search for a copy also look under the Elicar, Panagor, Quantaray, Rokunar, and Spiratone brand names.

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

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

Prices change all the time depending on supply and interest in manual focus glass. During the past several years, shooting film has risen in popularity, which has caused prices to go up.

Added upwards pricing pressure is caused by Pentax DSLR users collecting and purchasing lenses. Third party producers generally do not manufacture products for the K-mount, unlike the Canon EF or Nikon F lens mounts.

Economic conditions are constantly changing, and sudden events can quickly lead to large changes in prices. Nevertheless, the price differences between alternatives should be similar.

Checking out several sites is a sensible way to get accurate market information. If you’re lucky enough to come across an excellent deal, purchase it because the best deals don’t stick around.

That’s it for details about the best lenses for the MX. Here is some further information that will give you more info about the camera can be found at the links below: