Zeiss Contax lenses were all very good.
But as long as I get to pick the lenses I'll take the bet.
Phase 150D or Schneider 110LS shot near wide open on a high res back (e.g. 60mp) will show a difference compared to the Contax equivalents. Other lenses like the 35D are less likely to show such an improvement.
Mind you this difference may be entirely unimportant to many styles of image making and for many output purposes. For instance the 150D really excels at corner sharpness wide open, but in a portrait or fashion shot the corners may not have any content which you want to render sharply.
OK,
I've now reduced myself to the level of a pixel staring crazy. If I start shooting brick walls of fences, someone call the guys with white jackets and sleepy time hypos.
Anyway, these are real world samples, shot late at night. with a Contax and a Ziess 140mm lens on a p30+
A 7 year old back, a 9 year old camera and lens that was designed 15 years ago which was designed for film, not digital before anyone dreamed of a 30mpx back.
Phase had no imput to contax, contax obviously has no input to anyone anymore, my backs and cameras have never been mated, shimmed, examined or designed solely for each other.
Without editorial comment here are the results.
They were shot handheld, 1/90th of a second, with profoto acutes also handheld.
They were shot fast, probably 30 to 40 frames and on to the next.
For processing the sliders have been moved to add slight softness, not to present sharpening or over-sharpening.
Reduced full frame Full body Length Image
100% screen shot (open image in new window for detail)
Reduced full frame head and shoulders horizontal, more softness added with then noise sliders
100% screen shot (open image in new window for detail)
Anymore sharpness than this and we're not talking about a photograph, we're talking about a science project.
My point is not negative towards phase, because obviously equipment this old and this viable is a testament to Contax, Zeiss and Phase.
My point is after so many years , lens sharpness hasn't improved, camera usability hasn't improved, if anything it's less useable with stationary prisms.
I haven't shot a df+ or a new iQ series back, except fooling around in a camera store and though they are newer, nothing compels me to ebay what I use today and go to something else.
In fact the only medium format I would add at this point would be a Leica S2 because it works well with my contax lenses, used sells for 10 grand and though the tethering on the S2 is limited, for non tethering work it would be worth 10 grand for the form factor and lcd and honestly what else would I gain with another system?
_______________
But here's the bet.
I'll pick the studio and talent. My producer/stylist and partner will cast and wardrobe we'll bring in top level hair and makeup because if we're going to shoot a photograph, might as well produce something worth showing.
Then as a bonus we'll go on location, take some small tungsten and shoot the same comparisons in low light, using the tungsten for keys and accents.
You can use my contax for an hour then your DF and tell me honestly at the end of the session which camera you find more enjoyable.
In post processing you tell me what sensor works better under these conditions.
The bet, My p30+ against your IQ back. Well let's make it the cash value because on the very small chance I'd lose I'd wouldn't want to give up my p30+.
Sound good?
BC