Lens #4: Pentax 67 105mm F2.4

Initially, I did not plan to buy Pentax 67 105mm F2.4 lens, although its bokeh is deemed a gold standard for Pentax 67 and medium format cameras in general. I was quite satisfied (and am still satisfied) with my remarkable compact 90mm F2.8, which I had been using for many years by that time. It has become truly universal for me, a go-to during all my trips, with which I shoot literally everything, from portraits and street photography to landscapes and architecture.

However, I eventually decided to buy a replacement for my old and worn-out second camera body which I used as a backup. So, I found a very good offer but that camera was equipped with the Pentax 67 105mm F2.4 late edition.

It was out of my budget but I decided to buy this kit hoping to sell the lens after playing with it for some time. The reasons were (a) to earn some money and lower the overall price for the body by $300; (b) I did not need two standard lenses which would compete for the place in my backpack.

Thus, this lens became the fourth to come to hand. In practice, everything turned out a little different and I will keep it forever, I reckon.

Size and weight

The lens weighs 600g, just 110g heavier than its 90mm F2.8 fellow, which allows it to remain in the class of relatively light lenses in the Pentax 67 system. It’s also worth noting that medium-format lenses are generally quite heavy, and this difference in weight may seem insignificant.

But during trips I have to be practical and mostly opt for the 90mm F2.8 lens because of its compactness. It is smaller than the 105mm lens by 15mm. But in the sense of usability, you won’t notice much difference while shooting with each of these two lenses, although the outcome will certainly differ.

Image quality

It is very difficult and odd to describe this lens from the “image quality” viewpoint, as it implies a certain quantitative measurement of the parameters that I do not take note of, and it is not necessary in this case. But, in terms of image sharpness, when being stopped down to F8-11, it takes a picture that is very similar to the 90mm lens at the same aperture. You can hardly distinguish the resulting images after some time. This lens is valued for other features — its fast F2.4 aperture and bokeh effect. But let’s describe one thing at a time.

Close focusing

Its close focusing distance is just 100cm, as compared to 65сm in a 90mm lens. It gives 0.13× magnification ratio and the image area around 53×41cm, which is exactly the same as for 165mm F2.8.

It is necessary to use extension tube #1 to get more magnification when shooting close-up portraits.

Field of view

It covers 46° which is nearly equal to the FOV of a classic 50mm lens on the 35mm format. So, Pentax 67 105mm F2.4 is a classic standard lens.

Aperture

Pentax 67 105mm F2.4 has a 9-blade aperture, identical to the one used in the old Takumar 6X7 150mm F2.8, which was meant to complement the 105mm lens. Such an aperture configuration is really great for a smoother bokeh effect when the lens is stopped down.

But I rarely use it stopped down below F5.6 for taking portraits, so I will show several photographs shot with aperture opening up to F8.

Filters

The lens has a 67mm filter thread which works fine with both screw-in and special bayonet mount filters.

Hood

The original clip-on plastic hood PH-SB 67mm costs around $50.

But I prefer using the PH-SA 67mm designed for the 135mm F4 Macro and 150mm F2.8 lenses.

It doesn’t darken the corners on this lens too, even with filter. It also allows keeping only the one hood in my backpack for three lenses. Sometimes I use the Mamiya G2 bellows lens hood mounted with a special adapter.

Bokeh effect

At the fully open aperture, this lens creates a light, hardly noticeable swirl of the background, which I like very much. It adds a bit of “magic” to the bokeh effect making the 105mm lens stand out from its analogs even in other medium format systems.

A similar phenomenon is absent in the late 90mm F2.8 and 165mm F2.8 lenses, which are very good and also create a beautiful bokeh effect, but rather too “accurate” to my taste.

This lens has a smooth and very pleasant bokeh effect.

Other sample images

A bit of street photography performance.

Summary

It is difficult to give this lens an objective assessment after it received so many, mostly positive, reviews on the web. The lens has an F2.4 aperture, and that probably says it all. It was an absolutely unique feature at the time of the lens’s release in 1969, and it remains so now since no other lens with such maximum aperture has been released for the 6×7 frame size. Unless, of course, we consider different uncommon lenses such as Schneider Cinelux and others, which are not designed for Pentax 67, but can be adapted to it. It’s also worth mentioning that when Asahi entered the medium-format market, it simply had to create a lens with unique characteristics in order to gain a foothold on this market.

When I had only one lens, I had nothing to compare it with. Now that I have two standard lenses, it seems possible to make a direct comparison. But in fact, there is no need for this. For me, these are completely different lenses with clearly defined areas of application, which, in my view, do not really overlap. Although, you can certainly buy any of them, and just use it without going into much detail.

I mostly use Pentax 67 105mm F2.4 lens at the open aperture and occasionally at F3.5-4 when I have an even-colored background, so that the stopping down does not make it more “pronounced”. Although its constant comparison with 90mm F2.8 cannot be avoided, but I have defined for myself that I always shoot portraits of a large and medium-sized (medium shot or waist shot), at a distance of up to 4m with 105mm lens, and all the rest, with 90mm lens. It certainly does not mean that I always carry both of them with me and that when the distance is more than 4m, I immediately change the lenses. But I usually know what I am going to shoot in advance so I choose the lens accordingly. If I want to snap a street photo, I take 90mm lens, if I have a portrait session, I will certainly take Pentax 67 105mm F2.4 lens. And if I go on a trip, I’ll certainly take 90mm lens for its versatility.

It is 105mm which became a real “portrait” lens for me. And not 165mm F2.8, despite officially being labelled as such. And I would even dare say that Pentax 67 105mm F2.4 is a lens for the sake of which one can change the entire system.

Pentax 67 105mm F2.4 lens data

• Focal length: 105mm
• 35mm equivalent: 54mm
• Aperture: 2.4 ~ 22 (9 blades)
• Close distance: 100cm
• Magnification: 0.13×
• Picture area: 53×41cm
• Exposure factor: ×1.28 (+0.36EV)
• Effective lens speed: 2.7 ~ 24.9
• Optical formula: 6 elements, 5 groups
• Field of view: 46°/37° (Diagonal/Horizontal)
• Filter: 67mm, screw-in and bayonet
• Hood: PH-SB 67mm
• Case: S90-100
• Dimensions: 92×60mm
• Weight: 0.6kg

Yellowing and Radioactivity of older Takumars 6X7 105mm F2.4

Yellowing is a feature of the old versions of 105mm F2.4, SUPER-TAKUMAR/6X7, and Super-Multi-Coated Takumar/6X7 due to the use of radioactive thoriated glass in their manufacturing. The thoriated glass was a cheaper alternative to other non-radioactive varieties of optical glass with a high refractive index and to complex optical formulas.

However, not all S-M-C Takumars turn yellowish. According to my research, if the lens has a strong red-orange coating cast, it might be yellowed. The later editions of S-M-C Takumars with a purple-red coating cast might be not yellowed.

Yellowing causes color transmission to decrease and, of course, produce yellow-tinted images. So, the issue can be fixed by exposing the lens to direct sunlight or a UV-lamp with a mirror or foil placed under the lens to improve the outcome of this procedure.

If I am wrong or you have more details about the yellowing and de-yellowing of 105mm F2.4, please correct me.

Pentax 67 105mm F2.4 resources

• More sample images in Flickr group and at Lomography
• Disassembling and assembling Pentax 67 105mm F2.4

P.S.

Thanks for reading! I would be very grateful if you point out my possible mistakes, add extra information, or just share your experience. Scroll down to the Leave a reply section and share your thoughts about it. Your opinion is important for me. I enjoy answering your questions as the answers may often benefit many other readers and the process of answering allows me to better piece together my existing knowledge and find ideas to improve my articles.