Digital Back

[chwn]

My local photo dealer tells me that if I buy a digital back for my 203fe my lens' will not be sharp enough

for the back. He says that all past lens' are "soft" and not sharp enough for the digital resolution capable

of the digital backs. Is this true?

[stuart_richardson]

No

[russ_britt3]

He is not very bright.

[q.g._de_bakker]

He rather appears to be hoping that his customers are not very bright, so he can bring them to buying not just a digital back, but all of the rest too.

[ulrik]

Chris,

do not blame your dealer, he is telling you what the Hasselblad representatives told him. So he is sort of well-informed ;-) I was told during the Photokina that the Hasselblad H-system lenses are much sharper and contrastier than the V-system lenses. Which is quite an achievement considering that e.g. the Biogon 38, the Planar 100 and the Sonnar 180 are not that bad.

 

Ulrik

[q.g._de_bakker]

Much sharper and contrastier may be. But, Chris, even the less sharp and contrasty older lenses are much better than any digital back.<br>Maybe the day will come that digital backs are a match for even old lenses. But it's not today. Nor tomorrow.

[chwn]

By the way, this info came from Penn Camera in the DC area (one of the best photo stores in

the area). His point was that the digital backs lines of resolution is far greater than the old

lens' were designed to deliver. The new H lens have been designed to deliver sharper

images, allowing more lines of resolution.

 

I asked him if he was sure about this becuase I have some very good good lens' and he

insisted that it was true.

[leicaglow]

Chris, I have found color fringing problems with older Nikon lenses on new digital bodies. Upgrading the lens to a newer version did fix the problem. But in my limited use of even my oldest Hasselblad lenses on a Kodak DCS equipped 501 CM, I did not experience any issues.

[geoffrey goldberg]

He is right - sort of. There seeems to be some need to improve the lenses for digital work.

Note the new digital lenses from Schneider and Rodenstock. Also, Rollei is introducing new

Zeisss lenses for the Hy6, improved coatings (and who knows what else) on the standard

lenses.

 

Issues appear to be apochromatic and the linkage (in some cameras) between the lens

and the digital back - note Leica's coding of lenses to allow for some in-camera

correction, esp. of vignetting and color shifting in the corners.

 

Having said that, for most MF lenses, I'd be happy to stay with the regular lenses until

proven wrong. The high quality Zeiss and Schneider lenses can certainly cover most shots

without being changed - at least not for a while. On the other hand, if you are doing

close-up still life work, there might be an issue.

 

Some of this has to do with how hard you "push" the lens in its work - if you are making

massive enlargements, and have interest in fine line detail at the outer corners with wierd

lighting, these issues may emerge. But for normal work, I'd guess not.

[simon_platt1]

Chris

 

The problem is not resolution but other factors such as contrast and the angle of the light hitting the sensor.

 

A digital sensor even a 39M pixel one has nowhere near the ultimate resolution of film. But it is susceptable to relecting light off the front surface back onto the rear surface of the lens, and may show colour fringing at the edges if the light rays hit the corners at an angle.

 

Also there is a balance to be had between contrast and resolution, a lense that delivers a high contrast image will look sharp but may actually have less ultimate resolution than a lower contrast lens.

 

Digitally optimised lens therefore often have;

 

Revised lens coatings on the rear elements to reduce reflections with the camera.

 

Revised optical formula to try and make the light leave the lens in a parallel bundle.

 

High contrast to look sharp and actually have lower resolution because of that.

 

So the answer is that you may indeed need new lenses but you need to try it out for your application. It is not lack of resolution of old lenses that is the problem, as with everything in life it is a lot more complex than that.

 

Simon

[q.g._de_bakker]

Simon,<br><br>You're right. The lenses aren't the problem.<br>The sensor is.