Fujifilm GFX and Pentax 105mm 2.4

I’ve been holding off on writing this blog post for quite some time now but I feel confident that now is the time.  I’ve had some considerable time with the Fuji GFX50s as well as the Pentax67 105mm 2.4 having used it religiously on almost every job I’ve had.  I’ve chosen the Kipon Baveyes 0.7 focal reducer adapter to mount the massive Pentax67 glass onto the GFX.  This combination feels as substantial as a full frame DSLR with a 70-200mm lens attached however the results are unlike anything else out there.

If your reading this blog post then I’m pretty confident that you know about the Fujifilm GFX50S Digital Medium Format Mirrorless camera.  You are probably also aware of the many benefits of using adapted lenses on mirrorless systems.  What your probably wondering is how well the Pentax67 105mm 2.4 lens works on the GFX.  I like most of us out here are constantly trying to navigate through the vast world of modern and vintage glass to adapt to this amazing system.   I’ve definitely tried a few and while some are certainly better then others it also comes down to what look your after in the first place.   Figuring out the focal lengths can be confusing but you have to understand the size of the sensor in order to figure out what each focal length will yield in 35mm terms.  In order to do that the formula is FOCAL LENGTH X .79 = Percieved Focal Length on GFX.  

So 105mm x .79 = 82.95mm.

However when adding a focal reducer like the Kipon Baveyes 0.7 you have to adjust this formula.  This would new formula would be FOCAL LENGTH X 0.7 X .79 = Focal Length.

So 105mm x 0.7 x .79 = 58mm.

Which means the Pentax67 105mm 2.4 with Baveyes focal reducer gives you a normal prime lens for the GFX.  This was great for me because I’m in love with my Nikon 58mm 1.4G.  In fact my go to camera configurations have been a Nikon D5 on one side usually with the 58mm and the GFX on the other with the 105mm attached to a Moneymaker Strap.   Below are two images one from the Nikon 58mm 1.4g on a Nikon D5 (Left) and the second the Pentax 105mm on the Fujifilm GFX50s (Right).

Again, here is another set below.  58mm Nikon on left and 105mm Pentax on the right.

I know it may seem odd to shoot two cameras with a similar perceived focal length but I feel the two rendered are much different.  The GFX Medium Format image give you a different compression as you can see in the side by side images above.  Now this is in no way meant to be a side by side comparison between two cameras or even two camera lenses for that matter.  I’m simply using a 35mm equivalent focal length that is similar to the combination I’m using in the GFX. For close up head shots the two are very different.  Besides the obvious crop difference between both formats I can also see a huge different in the depth of the image.  This is not a very easy thing to describe but you know it when you see it.  Whatever you focus on will definitely stand out in the image and everything else simply melts away with a sense of depth and three dimensional look only a larger format can provide.  When capturing a full body portrait image your rewarded with the same depth and fullness as before.  Again critical areas are sharp and the transition in the foreground and background are rendered in such a perfectly even flow.  The Pentax 105mm seems to be especially good for this large format look due to the normal focal length but extremely shallow depth of field for a larger sensor.  On a Pentax 67 Camera body the 105mm lens has a 35mm equivalent of a 52.5mm f/1.15.  That’s some serious DOF.

  You can also visit https://mmcalc.com for focal distance calculations.

Above left is my Daughter taken with the GFX and Pentax 67 105mm and on the right the same location a few months apart with the Pentax67 Film Camera using the 105mm lens.

 A lot of Medium Format shooters are big fans of the Contax 80mm f/2 and for good reason.  I was a huge fan of this lens on my Phase One.  The problem with using this lens on the Fuji is:

A.  The focal reducer for this lens actually reduces the focal length too much and you end up getting a very distracting Bokeh/Swirl effect on the edges and you end up with an image that looks like you’ve captured it inside a bubble.

B. The lens will cost you upwards of $1500 or more. 

C. You can use and AF Adapter which is a positive however again your not getting the true focal length and not using the entirety of the lens. 

D.  The 80mm f/2 uses a very delicate focusing motor and from my understanding can be knocked loose easily causing focusing problems. 

 

With the Pentax67 105mm 2.4 you can find great examples from $400 upwards.  I would stick with either the Super Takumar Multi-coated version or the newest Pentax SMC version.  These example will undoubtedly give you a better lens coating to handle flare and contrast.  Focus is extremely smooth and you can still find the square style lens hoods but they can be costly.

 

For me the 105mm is perfect for my wedding work.  I’m able to tell a story with this lens because it allows for so much of the surroundings to play a part.  It renders an image that can be similar to a Large Format look whereas it’s just wide enough but the shallow DOF really allows your subject to pop and have considerable isolation.   Single person portraiture is a must with this lens.  The ability to capture razor sharp eyes and the rest of the subject features melt away are incredible.  Again, a real large format look that is very difficult to achieve with full frame 35mm cameras and even some medium format lenses.  The Pentax67 105mm makes easy work of this task.  I’ve also noticed that the 105mm has a minimum focus distance of about 2 1/2 feet. 

At the end of the day this fantastic lens has earned a premium spot on my Fuji.  This set up will make you work a little bit to nail focus but the results are truly rewarding.  Just punch in like I do to confirm focus or like others prefer and use the focus peaking feature and your sure to learn where the sweet spot is in no time.  Portrait work is amazing with this lens.

Just a few more examples below with the 105mm 2.4 Pentax 67 lens.

At the end of the day its about what works for you.  I love the fact that the Fujifilm GFX allows for so much exploration in this area.  It is so much fun to look for interesting glass both modern and vintage and find different results.  Im a huge fan of this combo and the 105mm probably lives on my GFX 90% of the time.  I've tried a lot of other lenses with great success and I will be coving those as well in the future.  Thanks for stopping by and hopefully some of the information I gave you helped you out.  To see more of my everyday work please visit my Instagram page JosephDagostinophoto or you can find the link on this website.  Subscribe or check in regularly to see more of my blog postings.