IT HAD TO HAPPEN...

Sooner or later every medium format discussion digresses into a dSLR vs medium format comparison. I intended to take the high road, but the fundamental differences between a dSLR versus medium format are undeniable. I arrived at this comparison because of several factors:

1. •Sensor Cast: Sensor cast has bothered me since day one. It was a non-issue with dSLRs, so the P25 is my first experience with it. Phase One passes it off as “lens cast”, which may be partly true - I can see how a lens could lead to ADDITIONAL cast or make the cast more noticeable. But the simple fact is - the sensor has a slight green to magenta shift starting from the left and going to the right. The cast is apparent even with no lens attached (shooting a piece of white acrylic held flush to an extension tube). After 100s of hours scouring the net, sensor cast appears to be a common problem. Supposedly a Leaf back can vary +/- 3% from quadrant to quadrant and be within spec. I found posts from both Phase One Plus and non-Plus back owners complaining of sensor cast, so upgrading to a Plus back is not a fix. I believe my P25 could be calibrated (and improved upon) by Phase One, but the warranty is through the dealer - and my dealer sucks. They acknowledged the issue but have done nothing about it in two months. If Linear Systems (the dealer) made an attempt to remedy the situation, then this probably would not bother me as much because I would know whether or not a greener pasture exists. Correcting for the sensor cast is pretty easy in C1, so the net effect is negligible. But the dealer B.S. has me really ticked off.
   

2. •Auto Focus: When it comes to manual focusing the Mamiya 645AFD II, I must be legally blind. Auto focus functions fine, but a single auto focus point at the center the screen does not help much. Center composition may work fine for catalog shoots and such, but for creative work center focus is limiting at best. The current state of AF technology available in medium format bodies lags far behind the dSLRs from Canon and Nikon. Since my eyesight isn’t that great, auto focus is an important feature.
   

3. •ISO 50: The files from the P25 at ISO 50 are gorgeous. At ISO 100 the noise begins to show and is similar to ISO 200 on the Canon 1Ds Mark II. I didn’t like shooting the Canon 1Ds Mark II at ISO 200, so shooting the P25 at ISO 100 doesn’t set well either. Finding enough outdoor light to shoot handheld at ISO 50 is tricky. The easy solution is a tripod which may or may not fits one’s style.
   

4. •Mamiya 645 AFD II Battery Life: Surprisingly the P25 does very well with the 2500 Mah batteries and lasts 300-500 clicks per battery, but the Mamiya 645AFD II eats AA’s like M&M’s. Six AA’s are good for maybe 200-300 clicks depending on how frequently the camera is used. I am using brand new 2000 Mah rechargeables. The 645AFD II battery meter has three steps - 100%, 25% and blinking (dead). One moment the batteries read 100%, suddenly the meter drops to 25%. And once the batteries hit the 25% mark they last for about ~25 clicks. Carrying a spare set of 6 AA’s is mandatory. Again, I have scoured the web looking for every power saving tip I can find. Nothing has helped.
   

My keeper rate with medium format has dropped radically compared to the Canon 1Ds Mark II. The reduction is due to out-of-focus shots - usually due to my poor manual focus skills. The low shutter speeds compound the problem. Both of these issues could be addressed by shooting with a tripod. Given a choice I rather not carry a tripod. When a keeper does work out, the P25’s file quality makes the picture all the more impressive. Compared to the Canon 1Ds2 the quality difference has fundamentally changed my benchmark for what a quality file should look like.

ENTER CANON 40D AND NIKON D300

During the past couple months I have tried various focus aides such as the Mamiya prism focus screen the the 2X flip-up viewfinder magnifier. These aids help to a degree, but only in the center of screen. Once the subject is outside of the center zone it is the wild, wild west of focusing. Out of frustration I decided the medium format rig would be used with just primes and for pictures where the digital back quality was a “must have”. All the other pictures could be taken with a Canon 40D or Nikon D300 with a basic kit lens. Since most of Mamiya’s new “D” lenses are in the $2500 to $4000 range, I figured a $2k dSLR set-up was pretty reasonable - skip a new Mamiya lens and get the dSLR instead. It was the same money, just being spent in a different way. I decided to try the Canon 40D and Nikon D300 side by side, pick one and sell the other.

The cameras arrived (a 40D body and Nikon D300 with the 18-200 VR). It had been a couple months since holding a dSLR, so I felt like a kid with a new toy. The LCDs, the fast focus, the lightweight, the battery... it was all so cool (again). The Nikon D300’s auto focus and metering were exceptional. I spent a couple weeks shooting each and the comparison was a toss-up - the Canon was good at this, the Nikon was good at that. There was one big issue with each - the crop factor. I like the narrow depth field look and the 40D/D300 did not excel in that area due to their crop factor.

The file quality from the 40D and D300 was not impressive. The noise levels were high (compared to the P25) and each system had boosted mid-tones which made the images somewhat muddy. Overall the files lacked clarity, crispness and/or the “pop” of the P25 files. In all fairness these are $1k cameras being compared to a $14k digital back - this is not apples to apples. However, the over-riding issue was the crop factor, so both cameras were sold.

ONTO THE CANON 5D AND 24-105L IS

The next option was the Canon 5D. The 5D’s feature list feels pretty thin compared to the Nikon D300. The 5D’s only selling point (in my opinion) is the 12.8 MP full-frame sensor. If you don’t need full-frame, by all means buy the D300 - it’s an amazing camera. To me full-frame is a big deal, so by process of elimination the Canon 5D was the only option at this price point.

The 5D files looks more or less as expected. The coloring is too red, but Canon is Canon. The P25 files have more snap or pop. On the plus side the field of view is “normal” and the lenses feel like they should. One thing led to another and I decided to compare the Mamiya 80mm F2.8 AF to the 24-105L IS @ 80mm. C1 Version 4.01 was used to process the RAW files. I could not get color to match exactly, but it is close enough. The JPEGs were saved as “Quality 10” from Adobe Photoshop CS3:  Mamiya / Phase 25 @ 80mm and Canon 5D @ 80mm

The following picture of the Tots bag from the P25 has extreme moire; this can be eliminated with Phase One C1  Pro Version 3.7.8. However, my license for C1 Pro is not working (another gripe with Linear Systems), so I could not use the Pro version of C1. Try to ignore the moire if you can.  Mamiya / Phase One P25 @ 80mm and Canon 5D @ 80mm

The full size P25 JPEG has more detail, but there are many factors here - 12.8 MP vs 22 MP, zoom vs prime, no AA filter vs AA filter, etc. I think it would be interesting to see how a Canon 1Ds Mark III would do in this test. These comparisons are for my personal amusement, so do not try to read too much into them. I prefer the look in the P25 files, but for $2000 the Canon 5D holds its own.