The Pentax MG is a great 35mm film SLR. This post is going to cover the 5 best lenses for the Pentax MG, plus a handful of substitute options.
In a rush? Here's the list of the best lenses for the MG:
- Kit Lens - SMC Pentax-M 50mm f/1.7
- Wide Angle Lens - SMC Pentax-M 28mm f/2.8
- Portrait Lens - SMC Pentax 135mm f/2.5
- Zoom Lens - Vivitar Series 1 28-90mm f/2.8-3.5
- Macro Lens - SMC Pentax 100mm f/4 Macro
The best Pentax K mount lenses are categorized by price range and type of photography. There are a number of proposed choices to pick that are in price ranges matching the value of the camera.
Table of Contents
Standard Focal Length Lenses
The following is a selection of 50mm focal lengths that are compatible with the MG. At the time when the camera was being sold as new, there was generally an offer available to buy a 50mm lens with the camera as a kit.
They are referred to as standard lenses because the angle of view is close to what the human eye sees.
SMC Pentax-M 50mm f/1.7
If you don't currently have it, an excellent first lens to get is the SMC Pentax-M 50mm f/1.7. The 50mm f1.7 is easy to find, has fantastic image output, is inexpensive, portable, and light. More photographs have been shot with this lens when compared to all other lenses.
You can also get the second version, the SMC Pentax-A 50mm f/1.7.
SMC Pentax-M 50mm f/1.4
Also found at: eBay, KEH, Adorama
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. An f/1.7 or f/2 lens will cost more. The former version, SMC Pentax, and subsequent revision, SMC Pentax-A, are both compatible with the MG.
SMC Pentax 50mm f/1.2
Just like all of the competing camera manufactures, Pentax created a 50mm "halo" lens. The resulting SMC Pentax 50mm f/1.2 is a large, fast, and high-priced hunk of glass.
The lens can be difficult to find because it can be used on Pentax DSLRs so the appeal includes more than use with film cameras. If you want to locate a copy you will need to check and see what is offered through weeks or months.
More Options
Down below are just a few other good lenses that are comparable possibilities. Along with 28mm or 35mm focal lengths.
SMC Pentax 50mm f/1.2 | Amazon | eBay | KEH | Adorama |
SMC Pentax 50mm f/2 | Amazon | eBay | KEH | Adorama |
SMC Pentax-M 28mm f/2.8 | Amazon | eBay | KEH | Adorama |
SMC Pentax 35mm f/3.5 | Amazon | eBay | KEH | Adorama |
Wide Angles
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 low-priced.
Not the best option, the SMC Pentax-M 28mm f/2.8, is still a good choice. In fact, plenty of people might not even consider it to be a wide angle lens. Even so, it is significantly less expensive than any wider option.
There's an abundance of wider Pentax focal lengths to pick from, but they're frequently much more expensive or third-party choices have noticeable amounts of barrel distortion. Also, it is easy to see chromatic aberrations and other optical flaws in third-party lenses.
More Options
The general relationship for prices is simple to understand. As the field of view gets wider, the lens will be priced higher. Lenses with large apertures will also be higher priced.
Be aware that these don't include 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 | Amazon | eBay | KEH | Adorama |
SMC Pentax-M 28mm f/2 | Amazon | eBay | KEH | Adorama |
SMC Pentax 18mm f/3.5 | Amazon | eBay | KEH | Adorama |
SMC Pentax 24mm f/2.8 | Amazon | eBay | KEH | Adorama |
Portrait & Telephoto Lenses
The 85mm focal length was not as frequently used as they are today compared to when the MG was initially introduced in 1982. As a result of being less expensive, 100mm and 135mm focal lengths were more frequently used.
The price difference is very clear when you view what's available.
More Options
There's an abundance of telephoto lenses to choose from. Focal lengths longer than 135mm and 85mm lenses will be expensive.
SMC Pentax 85mm f/1.8 | Amazon | eBay | KEH | Adorama |
SMC Pentax 85mm f/2.2 Soft | Amazon | eBay | KEH | Adorama |
SMC Pentax 105mm f/2.8 | Amazon | eBay | KEH | Adorama |
SMC Pentax 120mm f/2.8 | Amazon | eBay | KEH | Adorama |
Zoom Lenses
Prior to the introduction of autofocus, in the early 1980s, there were a small number of lenses manufactured by third-party companies that performed better than Pentax's offering.
Quite a few of these top performers were released with the Vivitar brand. Zooms with the Vivitar Series 1 branding are going to have the best optics you will see from a vintage zoom lens.
Sadly, obtaining copies of these lenses in usable condition can be quite difficult. Beyond that, no older zoom offers noteworthy performance. If you find one available for purchase that is cheap enough, it could be worth buying.
Vivitar Series 1 28-90mm f/2.8-3.5
- Covers a popular zoom range.
- Great for wildlife or portrait photography.
- A rare time when a third-party lens is the best choice.
Alternatives
Here are some more alternatives that you can look at if you want a zoom for your MG. None of them are going to be amazing, and you would probably be better off acquiring a couple of prime lenses instead.
SMC Pentax 85-210mm f/3.5 | Amazon | eBay | KEH | Adorama |
Vivitar Series 1 70-210mm f/3.5 | Amazon | eBay | KEH | Adorama |
SMC Pentax 45-125mm f/4 | Amazon | eBay | KEH | Adorama |
Pentax Macro Lenses
Macro lens choices for the Pentax MG have availability problems. The supply of Pentax K mount options is tiny, which increases prices higher than you would pay for equivalent Canon FD mount or Nikon F mount lenses.
SMC Pentax 100mm f/4 Macro
Also found at: eBay, KEH, Adorama
A few people online have experienced balsam separation of the front doublet. This is troubling because even a little separation will increase gradually and eventually make it unusable. If you see any evidence of balsam separation, avoid that copy and continue shopping.
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.
My favorite vintage macro lens I have used, the 90mm Vivitar, was made with a variety of camera mounts. However, it's difficult to obtain a copy that has a Pentax K mount.
The Vivitar 55mm is my second favorite vintage macro lens. An important difference is that it does have a smaller working distance than the 90mm. It is a great choice for table top and close-up photography, but a longer lens will be better if you want to take true macro photos at 1x magnification.
Both Vivitar macro lenses were built by Komine and were sold under various brand names. If you look for one also look under the Rokunar, Spiratone, Quantaray, Elicar, and Panagor brand names.
There is a Vivitar 90mm Macro Review and a Vivitar 55mm Macro Review.
For capturing images at macro magnification (1x), 90mm-105mm focal lengths are going to be the most popular choice. You'll have a big enough working distance to allow the use of flash, while staying away from substantial weight and excessive costs that longer focal lengths have.
More Options
Used Pentax Lenses
Prices change all the time depending on supply and demand in manual focus glass. Over the last few years, film photography has increased in popularity, which has pushed prices higher.
More pricing pressure comes from Pentax DSLR users collecting and buying lenses. Third party producers tend not to make products for the K-mount, unlike the Canon EF or Nikon F lens mounts.
Marketing conditions are continuously changing, and sudden events can quickly lead to large changes in prices. However, the price differences between options should stay the same.
Checking out a variety of websites is a smart way to get correct prices. If you're fortunate enough to discover an excellent deal, buy it due to the fact that the best deals do not last long.
What Lens Mount Does the Pentax MG Use?
The Pentax MG has a Pentax K lens mount.
Introduced in 1975, cameras being made today still use the Pentax K mount. It replaced the M42 screw mount that was used in previous cameras like the Asahi Pentax Spotmatic. Over the years changes have been done to add CPU contacts, electronically controlled apertures, autofocus, and metering information.
Provided that a lens has a physical aperture ring, it will be compatible with Pentax film cameras. Keep in mind, it doesn't make sense to spend money on expensive features that will not be useable. The exception would be if you already use a Pentax DSLR.
It's also possible to use the older M42 lenses by using an adapter. The previous Takumar lenses would be the best to use. Even so, I would not encourage doing this as finding them without tight focus rings can be challenging.
Lens Cap Size
The standard filter ring thread and lens cap diameter used on the majority older manual focus Pentax K mount lenses is 49mm. They were sold with slip-on caps, not the more commonly used center-pinch type today. Looking at what's available, you will find not very many lenses sold with matching caps.
Be aware that big front elements will need larger filters and caps.
The benefit of using a standard thread size is that you only need to have just one set of filters.
Pentax-M vs Pentax-A
Pentax-M and SMC Pentax lenses have a stop-down coupler which provides the camera to have a linkage to the lens. The stop-down coupler will allow 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 introduced the capability for the aperture in the lens to be controlled by the camera. This means that cameras that are compatible with the Pentax-A changes have the capability to do shutter priority and aperture priority modes.
Having said that, seeing as that feature isn't supported by the camera, it doesn't make financial sense to spend money on features that the camera can't use.
Related Posts
That is it for details regarding the best lenses for the MG. Here's additional info that will provide you with more information about the camera can be found below: