Monday, October 2, 2023

Pentax-A* 645 600mm f/5.6 – Fuji GFX100s


First yes, I understand it’s been a while since our last blog. No excuse other than we just didn’t feel like sharing…

If that first sentence didn’t put you off here’s something I feel share-worthy. For some time, the longest lens we had for any of the GFXs we owned has been the beautiful GF250 and 1.4 extender. The 250 equates to approximately 200mm in 35mm terms and the 350 (with 1.4 extender added) to approximately 280mm. From here on I’ll be dropping “approximately”.

600 with 1.4 extender @10 yards No Crop

What can a lens that was built for film and hasn’t been in production for well over 23-years. Good question which I hope to answer shortly.

2x extender @37 yards no crop

A 600mm lens built for medium format equates to 480mm while a 600 plus 1.4 (840mm) will equate to 672mm. Going whole hog and adding a 2x extender (1200mm) will produce around 960mm in 35mm terms.

There are a few downsides to using this lens. It is heavy, very heavy. Manual focus for those who care. The possible weak point is the adaptor you choose; my choice was a KIPON. The upside is that there are several adaptors, both new and old available. Likewise, the extenders. Lastly, did I mention it is very heavy?

2x extender @284 yards no crop

What you should consider. A very sturdy tripod. While I feel it might be able to shoot reasonably well off a good ball head, I opted for a gimbal head. Once again, while there are many out there my own personal choice is a Wimberly WH200. The WH200 might be a bit of overkill with a weight rating of 100 pounds I like it. A lot.

I will not go into any great detail regarding the extenders other than they are available.

2x extender @8-yards slight crop

The weakest link might be a good adaptor and as of this writing my KIPON has worked well. I ordered a new on and also was able to pick up a good used one. The thinking at the time was to have one attached fulltime to the extender I use the most. I have since changed my thinking and have ordered another one directly from KIPON. I’ll keep one attached fulltime on each extender and have one on the lens when I don’t need extension. Overkill? Yes, however my way of thinking is that it’ll make for far less of any accidental issues when trying the make a fast change in the field.

Granted I haven’t the lens very long I have found it to be a superior lens. Manual focus is no more difficult than any other lens I’ve used. Pro tip – make certain that you switch your GFX to M mode. Yes, that makes sense however in the heat of the moment it could be overlooked.

2x extender top image cropped shot @8 yards

This is a very long lens measuring well over 16 inches with just the adaptor and body attached and 19" with the 1.4. The weight, overall length and focal length make for a combination of instability. Vibration is not your friend. What I’ve learned so far is to shoot as fast as I can with as high an ISO that I can. I also keep the GFX on burst mode. I’ve attached a wired remote and use it about 50% of the time.

Both shot @ 688 yards no crop no post processing

The images provided here are all from the first couple of days of owning the lens. I was primary interested in how well the lens, extensions and adaptor work.

One addition thought. This lens comes with an attached lens shade which I used on all the images posted here. There is no vignetting

I hope to post more soon.


1 comment:

  1. I have been shooting this lens ever since my days with the Pentax medium format film cameras! It works well on my Fuji medium format digital cameras as well as
    my Leica S and Sony A7R3.
    Thanks for the article Don’