Pentax 645z Review Pt3 – The Lenses, CCD vs CMOS and 35mm vs Medium format.
Part 1 – The Journey
Part 2 – Image Quality
Part 3 – Lens options and CCD vs CMOS
Part 4 – Ergonomics and weight
Part 5 – Flash System
Part 6 – Conclusion
Part 7 – 100+ Uncompressed DNG’s to download
The Pentax 645 Lenses
The 645z lenses share a lot with Mamiya / Phase One. There is a legacy of low priced used glass out there (relative to new prices) for both the Pentax 645z and the Mamiya / Phase DF body. All the glass I purchased was used and works perfectly.
I’m very happy with all the lenses I have so far.
So far I’ve picked up the following:
- 35mm A (STUNNING)
- 55mm D-FA (Fast and silent, no CA anywhere)
- 75mm FA (Half the size of a Canon 50mm 1.8 and fast to focus)
- 120mm FA F4 Macro (Sharp enough to cut steel with)
- 150mm FA 2.8 (Stunning portrait lens but a little purple fringing if you blow the OOF highlights)
- 300mm A* F4 ( Or as I like to call it, the ‘Holy Mother of God’ lens)
- 45-85mm FA (Lovely, lovely lens especially considering it’s a zoom)
- 80-160mm which is very similar to the 45-85 but a bit heavier. Slightly soft wide open through the zoom range but I’ve another incoming to see if it’s a Friday afternoon lens.
- A full extension tube set and a x2 extender
I bought all of these lenses used for the same amount of money that I sold my Hasselblad HC 35mm and 100mm 2.2 lenses for…..which is something to consider. Even assuming the Hassy lenses were better (which they aren’t) it’s a case of two lenses vs seven.
There are two ways to look at this camera. From a medium format and DSLR point of view.
I was always looking for a replacement Medium Format system…not a DSLR replacement. I was overjoyed by how much nicer than the Hasselblad H series it was but after a while started to find shortcomings when comparing it to my 1DX.
Which let’s face it is a bit silly. Let’s deal with the silly first.
Compared to the Canon 1DX there are a few things I would change about the Pentax 645z:
- Bigger and faster buffer and faster ready time from when the last shot was taken. I’m not saying the current tech in there is slow. The Canon 1Ds3 only got to about 8 shots before the buffer filled and people were shooting weddings with that just fine.
- A programmable emergency settings button. On the Canon there is a menu option that allows me to program a custom function into a single button. On my 1DX I have the AF-On button set to go into a preset mode so if I’m set up manually elsewhere and I need to point and click without hesitation, the camera is ready to fire. For those one off moments.
- Full control over the Pentax on camera IR beam (540fgz). I like to shoot dance shots with a full manual flash system and sometimes rely on the on camera flash for manual fill. But mainly for AF assist. You pretty much have to put your hand over the camera lens to get the AF assist light to come on and that defeats the point of IR AF assist. I’m sure this can be fixed with firmware. I cannot use this in low light on a dancefloor as it currently is useless I ditch the AF and go manual.
- A joystick for the AF points. It’s too easy to press a button on the back of the cam to switch the function from AF point select to the white balance / camera styles. It’s my number one complaint on the camera, the AF assist being number 2.
- Exposure safety shift. I enjoy using the TV AV setting where auto ISO takes over, but if you want to underexpose the image it might not happen if there’s too much light.
But that’s it. Otherwise what you have is a pretty perfect camera compared to the 1DX. However I’m a simple shooter. I need Aperture, Shutter speed and ISO control. Other than autofocus I switch all the HDR, Noise reduction and other stuff off.
Compared to other medium format cameras.
Comparing a Hasselblad H series camera to the Pentax 645z is a difficult task but here goes…
I love the H series. I love the modularity. Being someone who is into robots and tinkering, the prospect of being able to take a solid camera and to turn it into separate components is a really cool thing for me even as a concept let alone in practice.
While it’s cool in a geeky kind of way it only serves one real useful purpose. Cleaning. Modularity is also a great feature to have if you want to change the backs…except you can’t with the Hasselblad H3II and H4 bodies.
It’s an annoying thing that makes no sense to me why they locked those backs, (and yes, I heard their reasons why) because essentially they made a DSLR, just one with more areas for water and dirt to seep into plus more weak links in the chain. Fortunately the H5D50c will now accept film backs. I’m unsure about third party ones?
The H system has something over the 645z in that all the lenses are leaf shutter and you can delay the curtain to reduce vibration from the mirror, which is more beneficial than you might think. Also their extension tubes and 1.7x tele convertor allows autofocus, which the Pentax ones don’t. I find that feature useful especially for close up portraits when I’ve hit the MFD of the lens.
I’m sure there are more things (like true focus) but for me at least those are the main ones because what the 645z has is the same as the H series does, but it does it much better overall unless you want tethering and shift movements.
The Hassy and Phase cameras are really good at that with the right setup.
The 645z beats the H series in so many ways and at such a lower price point it’s just silly. The ISO limit is higher, I’m getting usable shots at 12800 and that’s after pushing them another 2 stops (vs 6400 max on the Phase and Hasselblad versions). 1.5fps vs 3fps on the Pentax. There’s the tilt screen, live view, top data display, video (not that I need it), af points, superb weather-proofing and so on.
It also has dual card slots which are important for many if you shoot weddings, which I do. It means a lot.
CCD vs CMOS sensors
One of the biggest questions with regards the new CMOS sensor regardless of the body it inhabits is that the image looks different to CCD. In answer to that I can honestly say there isn’t any beyond standard colour profiling at the Raw stage and white balance. What is daylight for a H4D50 is different for the 645z. There is the colour blooming associated with CCD sensor that give it an organic film smear but the CMOS is better in the way it renders the image, the dynamic range and the overall manipulation of the files.
One thing you will find with the Pentax 645z files is that the raws come out of the camera flatter than Belgium:
Adobe’s colour profile for Pentax files are downright awful.
If you’re a Canon user you’ll find that on loading your Raw files there will be a selection of presets in the colour develop profile in Lightroom. Pentax has ‘Embedded’ and that’s it. But it’s miles better than Adobe standard.
I strongly recommend using a custom colour profile as part of your workflow. The skin tones need it.
It is said though that the flatter the image the more dynamic range you have to work with. This is true, in grading, the files are flexible like rubber and bounce better than a cheque written by Lehman Brothers. So win win all round.
If there’s anything else you’d like to know, please use the comments and I’ll do my best to help!120mm Macro, 150mm 2.8, 35mm A, 35mm vs medium format, 645z color profile, 75mm, 80-160mm, CCD vs CMOS, color profile, Colour profiles, Comparison, cs, depth of field, depth of focus, Dynamic Range, Extension tube set, FA, focal length, focal plane, focal range, hasselblad, High Iso, lens reviews, Medium Format Wedding Photography, Pentax 45-85mm, Pentaxe 645, raw develop profile, review, wedding photography, x2 Extender