[gavincato]

Imho most photographers with a Contax 645 camera and some lenses will switch to Leica S. Leica offers an adapter which supports the AF and f-stop setting of Contax 645 lenses. I don´t think a lot of them will switch to a Pentax 645 system. On the other hand, if a Contax 645 owner needs 645FF - a PO or (cheaper) HaBla back might be the better alternative.

hmm I dunno about that.

Switching from a relatively cheap contax 645 film setup to a $16k body, with a $1700 adapter, just to use a 80/2 on a crop factor leica where adding lenses on is 7-8k for each one.

You'd have to be pretty keen!

Before I got the 645z I looked into getting a back for a C645 but the speeds / iso abilities put me off as a wedding shooter. I'm sure it'd work great for some though.

In the meantime here's 2 from the weekend with a 645z and a contax 80/2

[Irie]

hmm I dunno about that.
Switching from a relatively cheap contax 645 film setup to a $16k body, with a $1700 adapter, just to use a 80/2 on a crop factor leica where adding lenses on is 7-8k for each one.

You'd have to be pretty keen!

True, but the 006 is in the $5K territory now...that is the one to get at the moment. Plus the adapter can be found for $1000ish.
I almost went this route instead of the 645z........almost!

[Sperdynamite]

Imho most photographers with a Contax 645 camera and some lenses will switch to Leica S. Leica offers an adapter which supports the AF and f-stop setting of Contax 645 lenses. I don´t think a lot of them will switch to a Pentax 645 system. On the other hand, if a Contax 645 owner needs 645FF - a PO or (cheaper) HaBla back might be the better alternative.

A lot of those Contax shooters are pretty attached to film. The rumors of film's demise are greatly exaggerated as they say, certainly here in the USA where we have multiple lab choices and plenty of Portra. 400H is extremely popular too but I don't trust Fuji to keep it around.

I shoot professionally in NYC and have a reasonable sized network, and nobody who makes money with their camera is shooting Leica S. If they WANT to spend that money it's better served with a Hasselblad H5D, and if they don't the 645Z is the obvious choice. Contrary to popular forum opinions pro's do look at price and the Leica offers nothing in terms of real ROI over a 645z, or film, or a FF kit. I do know some portrait pro's who've integrated the M system into their workflow but it's always augmented by a 5D, D750 or similar. Plus the word I've gotten is that the Leica 007 is worse at high ISO vs the Z. The CCD bodies are a complete non-starter. If a Contax 645 shooter needs FF digital they're mostly out of luck. It's the shutters in the bodies that are the weak link, and scarcity of parts generally. Even if Phase One offered the 100mp back in Contax mount at $10k (so complete fantasy land), it would be a hard sell unless someone started officially supporting the bodies, or better yet, making new ones. It's a damn shame because the Contax system itself is fantastic. It's really a shame that it was so short lived.

[mikeSF]

hmm I dunno about that.

Switching from a relatively cheap contax 645 film setup to a $16k body, with a $1700 adapter, just to use a 80/2 on a crop factor leica where adding lenses on is 7-8k for each one.

You'd have to be pretty keen!

Before I got the 645z I looked into getting a back for a C645 but the speeds / iso abilities put me off as a wedding shooter. I'm sure it'd work great for some though.

In the meantime here's 2 from the weekend with a 645z and a contax 80/2

Wow, gavin. Wow.

[Pål Jensen]

Just imagine the Pentax colours and bokeh at f2

Getting me excited just thinking about it.

It isn't bokeh but thin DOF. Bokeh is not DOF but how the out of focus areas are rendered. The difference in DOF between 2.8 and 2 is negligible and not detectable unless in close image to image scrutinizing.

---------- Post added 04-19-16 at 01:20 PM ----------

Personally I would rather see a 21mm f2.8 (or even f2.4), but that reflects my usage (not interested in narrow depth of field portraits but want medium format wide view star shots at relatively low ISO).

The 25/4 already weights 1kg and cost $5000. A 21/2.8 for the 645 format will weight 2kg and cost $30000. You are far better off with an FF camera if you want fast lenses.
Fast 645 glass isn't really needed. DOF is already thin enough for the 645 system to such an extent that many will have problems getting en ough of it if you are used to smaller format. For fast lenses, a smaller format like FF, is far more cost effective.

[Simen1]

I have to disagree. Using a f/2,8 lens on 645 yields about the same DoF as using a f/2,2 lens on FF. You can get a lot shorter DoF on FF then on 645, because 645 lacks very large aperture lenses. The same thing goes for noise when choosing an ISO that gives you the same shutter speed/motion blur. Another thing is that large aperture wide angles are not about the DoF, its about light gathering.

But I agree the wish for a 645 D-FA 21mm f/2,8 is quite unrealistic, mostly because of the long flange distance. If Pentax ever makes a mirrorless 645 with short flange distance, it could be realistic both in terms of decent price and weight. Although I would suggest using a smaller format, normal prime and stitching technique for star shots. A 21mm f/2,8 or 2,4 for 645 would be more useful for aurora and meteor hunting, where you need stitchless large field of view and high light gathering capability.

[whwang]

But I agree the wish for a 645 D-FA 21mm f/2,8 is quite unrealistic, mostly because of the long flange distance. If Pentax ever makes a mirrorless 645 with short flange distance, it could be realistic both in terms of decent price and weight. Although I would suggest using a smaller format, normal prime and stitching technique for star shots. A 21mm f/2,8 or 2,4 for 645 would be more useful for aurora and meteor hunting, where you need stitchless large field of view and high light gathering capability.

I agree with your analyses. At this moment, it is a much better idea to use 135 FF with a longer lens to make mosaic images, rather than using 645z with a shorter lens to take single shots. However, this is exactly because of the lack of a high resolution, large aperture lens for 645z. If such a lens exists, one can use it on 645z, and then mosaic, to create even higher quality images to compete against a 645 FF camera. This is sort of what I was hoping to do.

[Pål Jensen]

Fast medium format photography isn't cost effective and hence will forever be strictly niche. Extremely few are willing to spend thousands of dollars extra in order to gain one stop that could equally be achieved by increasing ISO one stop for free (and probably still get better image quality than the alternatives). If this isn't good enough, FF is a much better alternative.
What Pentax needs are more lenses. Zoom lenses and reasonably sized and priced lenses. This is what it is needed to compete with other digital SLR systems.
I'm convinced that the 645 system will see a FF (645) in due course...

[Sperdynamite]

I personally can't imagine that the Astro crowd wouldn't be currently satisfied by the A7RII and the Batis/Loxia offerings. 25/2, 21/2.8, 18/2.8... I know from my RX1RII that the BSI sensor is a true upgrade. It nearly competes with the Z in some ways.

[Simen1]

@ Pål Jensen: I would rephrase your first sentence to "645 isn't cost effective" and end the sentence there. Thats the problem. The Pentax 645 system could die if it doesn’t get any advantages over FF. Your solution are way too little. Remember that where you could use f/1,4 at at lets say ISO 1600 on FF, you have to use ISO 6400 on 645 because its only has f/2,8 max aperture, in order to get the same shutter speed and exposure. The 645Z have a size advantage comparable to about 0,7 stops, so I would expect comparable noise to FF ISO 1600, at ISO 2500. In other words, using ISO 6400 will most likely be much more (1,3 stops) noisy then ISO 1600 on FF. I think the 645 format deserves a longer life, but not much longer with the existing mount.

Larger aperture normals and mild telephoto are very possible on 645, but large aperture wide angles are difficult (large and expensive) because of the long focal flange distance.

@Superdynamite: The A7RII lacks astrotracer and a reasonable file format (compressed lossless raw). I would rather have a K-1 with a Samyang or Irix lens.

[whwang]

@Superdynamite: The A7RII lacks astrotracer and a reasonable file format (compressed lossless raw). I would rather have a K-1 with a Samyang or Irix lens.

What's worse, way worse, is that the A7X series try to filter out hot pixels during long exposures taken in the Bulb mode. This simultaneously filters out stars, and this cannot be turned off. See an example of mine made with A7R and Sigma 50/1.4, where many stars in the top two frames disappear:



This problem can only be avoided by taking exposures in the M mode, and therefore the exposure time can't be longer than 30 sec. To achieve a deep image, one has to take many many 30 sec exposures, instead of, for example, just tens of 5 minute exposures. This significantly increases the post-processing time, and the size of the memory card. Also, this leads to compromised image quality if one takes pictures under very dark sky, where longer exposures (of single images, not total integrated exposure) are required to completely eliminate the readout noise of the camera.

This is the same mistake Nikon made 10 years ago, and this is one of (if not THE one) the key reasons that lead to Canon's dominance in amateur astrophotography. Now Sony makes the same mistake again. People complain to Sony about this for more than a year, and there is no sign that Sony is going to address this any time soon.

[gavincato]

The difference in DOF between 2.8 and 2 is negligible and not detectable unless in close image to image scrutinizing.

well, I can tell that a mile apart.

I have here the pentax 75/2.8 and the contax 80/2 - I really like the 75 - but the 80 looks completely different at f/2 - it's not even close.

[Pål Jensen]

@ Pål Jensen: I would rephrase your first sentence to "645 isn't cost effective" and end the sentence there. Thats the problem. The Pentax 645 system could die if it doesn’t get any advantages over FF. .

The 645 system has an advantege over FF. it never had superfast lenses even in the film days when you really needed it (when 200ISO was fast). No reason for it to die now when astronomical ISO values are available. What may "kill" the 645 system is price and size.

[Simen1]

The 645 system has an advantege over FF.

As I mentioned in another thread, I really struggle to see that its got an advantage:

- Less DoF then FF (due to much smaller aperture lenses) .. for the thin DoF-people
- More ISO noise then FF (again due to much smaller aperture lenses)
- In some situations not even better detail resolution then FF. K-1's 36 Mp + pixel shift resolution (PSR) will give comparable resolution to single shots from the bayer sensor in 645Z. The 645Z will only have a resolution advantage in those cases where PSR can't be used. With lenses in the same price class that advantage will be small (about 20% in linear resolution).

What may lead to the death of the 645 system is the lack of advantages over FF. They can keep it alive by doing three things. Two simple and short term. One expensive long term:

- Offer a larger aperture lens (or lenses as in plural)
- Increase the sensor size to FF 645
- Build a new mount with a short focal flange distance, other modernized features and a lens line up to go with it.

My guess is that Pentax will do both the former in the coming two years and that they will evaluate the latter and maybe do a pre-development study soon (maybe they already have). But I doubt we will see a new mount product launch before 2020.

[Pål Jensen]

As I mentioned in another thread, I really struggle to see that its got an advantage:

- Less DoF then FF (due to much smaller aperture lenses) .. for the thin DoF-people
- More ISO noise then FF (again due to much smaller aperture lenses).

The advantage is better image quality. DOF is a red herring; 99.999% of all photography is not about very thin DOF, and if you want thinner DOF that is achievable with an MF camera, something I find odd, you are better off with a format where such is more cost effective and practically achievable. If anything, the 645 format and larger ones, struggles with too thin DOF. That's why many 6X7 shooters switched to large format in order to get enough DOF due to their tilt/shift movements.
ISO noise is function of the sensor, not the lens.
Trying to normalize everything to one format as a standard to be judged against is counterproductive. Different Formats sell due to the fact that they are different, and it is purely subjective what parametres are desireable; it not a given that any photographer think the DOF he gets wide open with the 77 Limited is the preferable DOF at this speed and angle of view.
What can kill sales is too high price. The fact that pentax is a field camera also put constraints on how large bodies and lenses can be before people think twice.