Affordable high performance digital backs for amateurs and professionals (V1.0)

 

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 Hasselblad SWC with Leaf Valeo-22 / portable pack

 

 

 

Price is not a bottleneck any longer

 

In fact, digital back never has been released in affordable price. For example, Phase one IQ-180 is coming out with $38,000

in 2013 while the most expensive 35mm DSLR, Canon 1Dx or Nikon D4 released about $8,000. It is awesome 5 times more

expensive!

 

Digital backs in old days also released as the most expensive image capturing tools at that time. You had to pay $28,000 for 

Leaf Valeo-22 when it’s hey days. Considering inflation over last 10+ years, Leaf Valeo was not cheaper than current IQ-180

for photographers, even though current price of Leaf Valeo is unbelievable $1,000+ range. Such a humble low tag.

 

Targetted user for digital back is small number of experts, professional photographers who can charge what they want to

clients with their work. They are mostly big commercial studios backed by Furtune 500 type companies. They require

expensive, highest-performance equipment no matter how big depreciation of huge investment is. Of course, there are

always wealthy amateurs who can enjoy awesome cameras, as like Mercedes or Ferrari they drive to buy a coke in

Seven Eleven. But their population is somewhat limited to boost up digital back to volume production market.

Electronics – the law of inverse square

However, the value of digital camera is dropping in inverse square law as time goes by, like all the other electronics.

High-end digital back is no exception. If you wait patiently when you have limited budget to enjoy the hobby, or you

recently build up professional photographer career and not achieve commercial success yet, the day will come finally

when you can buy digital back without concerning about bankrupt.

 

What are the criteria of cheap, inexpensive or affordable?

 

The flagship of 35 mm full-frame DSLR, Canon 1Dx & Nikon D4 are around $8,000 which is still far stretched for the most

amateur photographers. If we come down to 5D Mark III or D800 level, price dropped to certainly ‘considerable’ range like

$3,000. Moreover recently released entry level full frame camera from Canon and Nikon is even lower price around $2,000.

Most amateurs and semiprofessionals stay within this price range to be competitive and comfortable. Taking account

old digital backs were extremely expensive yesterday, if used one calls below $3,000 today, I would say it is affordable

for most of serious photographers.

As photographer, you don’t really need to rely on the newest and highest performance digital back to achieve excellent image

quality. Digital back broke through ‘Mach 1’ barrier already when they started to deliver 22M pixel in 36mm X 48mm size sensor.

I know suppliers continue to increase pixel density and sensor size, but we’ll never use their maximum performance anyway.

They reached enough level for imaging quality 10 years ago, and still fulfilling most demanding photographer’s requirements

as of now. So why not enjoy available and affordable digital backs instead keep them in a wish list, 10 things to buy before die?

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Image quality or Image size?


If you compare 22M and 39M pixel digital back, what do you expect?


You surely will have bigger image SIZE out of 39M, but may not image QUALITY

Image quality compared to 35 mm full-frame sensor:

Older digital back has 16M pixel or 22M pixels while some of current full frame 35mm camera (Nikon D800, SonyA7) have

36M pixels. Moreover 40M or 50M pixels DSLR will be available in near future, I bet. Question is, old digital back in

22M pixels (36mm X 48mm) still deliver better image quality than 35mm full frame (24mm X 36mm) in 36M pixels?

 

Nowadays it is very true, 35mm full frame camera image is so good that diluted strong points of digital backs essentially.

There is no practical limitation on 35mm DSLRs in commercial applications as well. But even if we can take 20M pixels

with hand phone camera in these days, do you believe it delivers the same image quality of Canon 5D in only 11M pixels?

 

How about 16M pixel micro 4/3 vs 16M pixel full frame image quality? Both have the same amount of pixels but full frame

sensor has 4 times larger sensor than micro 4/3. It means individual cell (piexel) in full frame is 4 times larger than micro 4/3,

which will improve image clarity and S/N ratio significantly. Sensor area influence to perceived image quality as well with

shallow Depth of Field, which split ‘main subject’ from ‘background’ and deliver clearer impression to viewers.

In short, image quality we all concern is not only related with ‘number of pixel’ but also many other factors.

 

Image quality contributing factors

o sensor area (dynamic range, DOF)
o individual pixel size (S/N ratio, noise level)
o the number of pixels (resolution)
o CCD or CMOS (sharpness, higher ISO)
o AA filter used or not (sharpness)
o 16bit vs 12bit A / D conversion (color, tone)
o Image processing (color, tone, noise….)
o lens performance (sharpness)
o the mirror shock (sharpness)

Why choose medium format camera / digital back?

Changing to digital back means you decided to use medium format camera. It will induce fundamental change to your

photograph, how to see, handle, process the photos. As they did in the past, medium format camera and 35mm camera have

their own Pros and Cons, specific constraints, and their own area to be applied. It is not possible to eliminate either one of

system entirely, hence many photographer had and utilized both systems depending on purpose and target. In digital era, it is

the same as before, except 120 films (medium format) is replaced with 36 X 36 or 36 X 48 digital backs. Of course, unlike film

era when you need to pay the same amount of money for 120 film snd for 135 film, digital back requires your fortune invest

to start up.

There is no ‘burst’ in digital back as you might hope. Fastest rate is 1 picture per 0.8 second or in average 1.5 to 2 sec.

Therefore you cannot keep your 35mm way of working, which fires 7 to 8 picture per second, then pick up 1 good shot later.

No matter how busy the situation is, you have to prepare carefully and perform accurately to take one single picture.

Indeed, working with medium format camera should be right on everything from the beginning. It forces photographer think

before press the shutter, check composition, lighting, exposure & wait until right moment. Most of all, you have to predict or

presume what kind of picture you will get and what processing / photoshop work will be applied to make final result.

As conclusion, the reason we want to use digital back, no matter old or new, is not for high definition, sharper images

in many mega pixels. It is because digital back will force self-training to pursue fundamental change, how to approach

toward photography as a masterpiece.

What are available and useful digital backs?

Some of digital backs found on open market or Ebay are looking ridiculous for the eyes accustomed in modern digital cameras.

Yes, digital back has existed long before it really performs as useful digital medium. They are made of big & prehistoric

look, in 4 M, 6 M, 11 M pixels with the same at best with or smaller than full-frame sensor. They most likely were produced

before 2002.

They are not only outdated so long, software discontinued or even you find old software, it is an awkward to take full

advantage of. At the end, there is no benefit compare to current full frame sensor. Therefore, it would be good for a paper

weight and excluded from consideration entirely.

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Left is Kodak 645M which has 16M (36mm X 36mm) & Right is Leaf Valeo-22 (36mm X 48mm)


Both are excellent choice for photographer who’s seeking extreme image quality (not image size)  

1st generation digital back

From 2002 onward, digital back sensor enlarged to 36 X 36 (more precisely 36.7mm X 36.7mm) which really ‘mean something’

as medium format camera. Square format is familiar who used to use Hasselblad and/or Rolleiflex. It also dominated medium

format in film period very long time. So let’s call this, square format in 36 X 36, as the first generation of meaningful digital back.

From this generation, it is worth to accept hassle and tackles induced by medium format camera.

Representative models are:

– Kodak DCS 645 Pro back (for Mamiya 645, Contax 645 & Hasselblad H)

Kodak DCS 645 Pro Plus back (for Hasselblad V, technical cameras)

Phase one P20 (for Mamiya 645, Contax 645, Hasselblad H & Hasselblad V)

Hasselblad CFV (for Hasselblad V)

Imacon V96 (for Hasselblad V, technical cameras)

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Kodak 645M is again left side and Leaf Valeo is right side.


Even though 2 backs are not seated in parallel with focal plane, the size difference of these 2 backs is not lens’ perspective exaggration.


Leaf Valeo-22 is obviously smaller and lighter compare to Kodak 645M.


There are 3 items separated from Valeo back, but will discuss full details about them in next chapter

2nd generation digital back

Soon after, bigger image sensor introduced in twice the size of 35mm full frame (36mm X 48mm). There are two distinctively

different sensors in here. One is produced by Kodak and the other by Dalsa (Phillips), and both deliver 22M pixels with

highly recommended crisp image generated by 9um cell. The main difference in between Kodak and Dalsa is that Kodak sensor need wakeup signal for operation while Dalsa sensor not due to their difference in chip structure. 9um cell is the biggest cell size in digital back sensors. And with enlarged sensor dimension, digital back brought different level of photo expression which 

could be done only with film by that time.

In addition, makers introduced budget-priced digital back which has slightly smaller sensor (33mm X 44mm, 17 MB) to boost

sales. This is cheaper version of 36 X 48 brother but there is 1 big advantage of its own. It has faster burst rate than 36 X 48.

Let’s call these 2 type sensors as 2nd generation since only difference of them is slightly different dimension.

2nd generation digital back has very good price-to-performance ratio in these days. Original digital back users upgraded to

higher version like 39M, 50M (same sensor size of 36 X 48) or 80M (41 X 55) thus 2nd hand 17M or 22M digital back is now

available from $1,000 (Leaf Valeo-17) to $3,xxx (Phase one P25). This is the group of digital back for amateurs & professionals

who’s seeking high end image quality within limited budget.

Representative models are:

– Leaf Valeo-17

– Leaf Valeo-22

– Leaf Aptus-17

– Leaf Aptus-22

– Phase one P21

– Phase one P25

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Size comparision Leaf Valeo-22 (Right) vs Leaf Valeo-17 (Left)


Valeo-22 has 36mm X 48mm while Valeo-17 has 33mm X 44mm


Actually sensor area differerence is not so significant as concerned. 33 X 44 is excellent entry level, still powerful tool

2.5 generation digital back

Newer type digital back follows trait in 35mm battle, Pixel War. Even though they have the same sensor size (36 X 48), they

shrunk cell size from 9um to 6um to increase number of pixels and ended up 39M digital back. Of course they are better(?) in

many ways, but price reaches up to $10,000 even in used condition. Therefore we have to wait couple of more years patiently

if want to use this one without pain. I would say they are out of our scope as affordable digital back for a while & drop it

out of discussion.

Representative models are:

– Leaf Aptus 75

– Phase one P45

– Hasselblad CFV-39

 

3rd generation digital back

The most recent release is even bigger, 41mm X 55mm sensor digital backs franked with 80M pixels. It finally reaches to 1:1

crop ratio in 645 format while 36 X 48 sensor has 1:1.1 and 33 X 44 has 1:1.3 crop ratio. This is out reach products, and I will

just watch out next 10 years…

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Different strategy on display


Kodak 645M has small but on board LCD screen, while Leaf Valeo connect HP IPAQ has much bigger display throguh WiFi.


But hand held display like Leaf Valeo is outbeated by handy / easy on board display, so can not find any other example than Valeo

4th generation digital back in future ? Live View

The first system camera ever was large format which is an extension of Obscura. With dominance of 35mm digital camera

though, medium format system sustains their life line barely and large format system entirely dead. When large format film

camera was still available on the professional retailers catalog, 4X5 field camera was regarded as a standard tool for

landscapes and architectural photographer who’s seeking ultimate image quality and freedom in movement.

But tilt and shift function which make large format camera so unique and irreplaceable can be done in Photoshop in these days

as long as you have enough image area to crop out. Now 35mm digital camera surpasses medium format film camera’s imaging

quality and medium format digital back surpasses 4X5 or 8X10 large format film camera’s imaging. I cannot foresee any

possibility to revive those days, Super Anguron, Symmar, Protar which illuminate upside down picture on frost glass.

Another reason is cost constraint in sensor business. To create a digital image sensor, large investment has to be done.

More significantly, as the sensor area increase, production cost jump as 3 fold exponentially up to where it makes no sense.

Only option for large format is scanning back. It is the same as ordinary scanner in our office and home but it scans aerial image

projected by lens instead of paper. Unfortunately, it is not practical solution too. Scanning time takes couple of minutes which

prevent any application for moving subject.

Unless production cost reduced in quantum degree, the next generation of digital back is unlikely larger than current, 3rd

generation except very slight margin. More likely it will be different cell structure, CMOS instead of CCD, to equip with live view

function.

Live view in digital back can solve one of fundamental problem since photography invented. The film is sensitive material on 

light which is basically chemical substances in the gelatin base. No matter what, camera makers had to think out of box to

figure out where exactly the focused image (aerial image) is and how to make user set the position properly.

1) First solution is using frost glass. Through it, you can focus to aerial image, then remove glass, insert film holder and hope

    the film located at the same position with aerial image. Because film plane is sensitive only a fraction of a millimeter error,

    need to stop down a lot to compensate misalignment respectively.

 

2) Second solution is using 2 prism to measure distance from camera to subject, and turn focus ring of the lens to match

    2 images produced by 2 separate prism in eye piece. Each lens has to be adjusted to match ‘focus cam’ with prism

    adjustment arm of the camera and so to aerial image.

 

3) 3rd solution is similar with 1st one. Instead of removing frost glass, it slaps upward to clear light path from lens to film. Again,

    the mirror unit should be precisely match with lens flange to film distance, otherwise it will not record as what you see in the

    screen.

When film replaced with image sensor, and then eventually CCD switched to CMOS, we have possibility to look what really

happen on focal plane or aerial image as live view. Now almost all APS-C, full frame digital camera have live view capability

but it has not applied to digital back yet. It is very strange because sensor technology advanced so much in CMOS, so

live view, high ISO, low noise, long exposure are easily available. But no digital back produced with CMOS sensor so far by 

2013. There is no technical barriers in here, whatever was, already overcome for 35mm mass production process. Increase

sensor size twice is not a technical issue. It is just a matter of commercial decision.

Once CMOS live view digital back is available, medium format or large format camera will have breakthrough technology of

focusing which has been painful so much so long. When we use digital back to technical camera (aka large format),

sliding back used to switch frost glass to digital sensor easily. This sliding back has to be machined very precisely to match

glass plane to sensor plane exactly (minimum 1/20 mm torerance) if not, you’ll always ended up front or back focus.

It costs a lot to get sub-millimeter precision in mechanical works, and it’s heavy and bulky, still has misalignment risk by

improper handling as always.

If live view used, what you see on the screen is what you get with sensor. We can eliminate those hassles altogether.

We can rely on less precision mechanism costing significantly low with upmost precision in focus. Now all of 35 mm

camera made of CMOS, almost all have live view function. I believe the same technology will be applied to digital back

in near future.



 

 

 

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Mighty landscape and Architechture camera, Hasselblad SWC revived with powerful, yet cheap enough Leaf Valeo-22 / portable back