Digital backs for 4x5 cameras

so in other words you really don't know anything first hand, only the blurbs?

tell me... what size sensors are those large format digital lenses designed for?

OK Bob... I did some investigating, just what I suspected... its all about format/sensor size and equivelents. Not analog vs digital. The lenses you classified as LF are actually only good for a limited image area so the size of the sensor is alot smaller than 4x5, more inline with MF.

When you reduced format/sensor size, the lens is proportionally reduces in focal lengtht and circles of confusion are smaller as well... that's the drop in DOF you are trying to compare..The largest sensor available commercially is still not large enough to say its the same as 4x5, even an equivalent is not the same to say its lacking in any way.

You cant just say because your digital lens is optimized at F8 and a 4x5 analog lens at F22 ,makes the digital lenses superior.. its about physics, not faults digital vs analog.

a 4x5 sensor is coming soon according to one manufacturer, thats exciting to see, but it will cost as much as a mansion with full service living in.

So Id like you to read the links above, it will help you understand what we were disagreeing about? Im sure that will make it a bit more obvious.

No Ron, the digital sensor is ¼ the size of 45. To achieve optimal performance with the sensor you would need to shoot around f8. And that is what digital lenses are corrected for. On the other hand analog lenses are designed to perform optimally at 22. Using those lenses on a digital sensor at f8 you will not be at the optimal performance of the lens and at f22, with the digital back and an analog lens you will be in diffraction.

Additionally the digital lenses have higher resolution, check and compare MTF, less fall off, check the graphs, less distortion and better color correction, again, compare the graphs.

Then go look at what very large prints look like from a digital back and with digital lenses.

Yes digital lens is a bit misleading, they will outperform any medium format lens on film with a quality roll back! But there design purpose was superior results on digital backs on digital platforms, be that an Alpa or a Linhof M679 series body.

Better then you do. I also know the quality possible from quality digital.

Don’t make dispersions without knowing background. I assure you my photographic experience is far deeper then yours!

Ron, go to a digital dealer and take a professional demo on quality digital backs and what they are capable of. At this time you are speaking from ignorance!

There is a cure for ignorance, but stupid is forever. You've been blocked!

Hmmm! Schneider's website shows 'discontinued' for all their Digitar range, and the links to PDF info come back with a 404 error.

Many of Rodenstock's 'digital' lenses are also discontinued. So I guess not many buyers were convinced of their superiority enough to pay $2000+ for the privilege of using them.

What info remains shows they are only designed to cover a 54x44mm frame. That's a long way short of the OP's request for digitising a full 5" x 4" frame, making the lenses an irrelevance in this context. - Regardless of any computer-generated theoretical MTF curves, that in any case would only apply to a perfectly manufactured and assembled real lens.

I wonder if the reason for special digital lenses is the same that some of the wide-angle Leica mount lenses needed to be re-designed. Digital sensors, which aren't simple flat receivers, but have real thickness with levels of different components that the light has to pass through, don't like light that comes to them at a steep angle. but film doesn't care. That isn't a problem in the middle of the image where the light is straight through, but is a real issue out towards the edges.

I suspect that non-retrofocus lenses, which put the back element very close to the film, are the worst offenders here. That category contains mostly non-SLR lenses, since SLR lenses were always designed to sit farther from the film to allow room for the mirror. RF 35mm cameras and view lenses didn't have that problem, and usually better non-retrofocus lenses are easier to build than retrofocus. I can easily see a situation where film LF lenses would not be optimal for digital, since the same problem has already happened in 35mm, and was dealt with through new specialized designs.

It wouldn't surprise me at all if the makers of LF lenses had faced the same problem. As for the lack of LF digital lenses in production, I guess everyone must have noticed by now that if you're shooting smaller formats that are quickly approaching 100MB, LF photography is an evolutionary dead end. Anything you could do in the camera now gets done in the computer, and is easier.

Hmmm! Schneider's website shows 'discontinued' for all their Digitar range, and the links to PDF info come back with a 404 error.

 

Many of Rodenstock's 'digital' lenses are also discontinued. So I guess not many buyers were convinced of their superiority enough to pay $2000+ for the privilege of using them.

 

What info remains shows they are only designed to cover a 54x44mm frame. That's a long way short of the OP's request for digitising a full 5" x 4" frame, making the lenses an irrelevance in this context. - Regardless of any computer-generated theoretical MTF curves, that in any case would only apply to a perfectly manufactured and assembled real lens.

Except for the problem that you mentions about a typical DSLR sensor sitting deep from the lens mount I think the OP idea is a good one. Of course it only works for subjects that don't move at all. Using a small sensor and with fewer MP the OP could get a file with good number of MP by shifting and stitching. The resolution per mm is low because using traditional larger format lens the resolution is low any way but the resulting image would be of high details comparable to that of film.

Hmmm! Schneider's website shows 'discontinued' for all their Digitar range, and the links to PDF info come back with a 404 error.

 

Many of Rodenstock's 'digital' lenses are also discontinued. So I guess not many buyers were convinced of their superiority enough to pay $2000+ for the privilege of using them.

 

What info remains shows they are only designed to cover a 54x44mm frame. That's a long way short of the OP's request for digitising a full 5" x 4" frame, making the lenses an irrelevance in this context. - Regardless of any computer-generated theoretical MTF curves, that in any case would only apply to a perfectly manufactured and assembled real lens.

Joe, maybe you didn’t download the digital lens brochure that is available, right now, on the Rodenstock Photo factory web site? Here is the link, and it includes digital lenses with image circles up to 150mm.

http://www.rodenstock-photo.com/Archiv/Objektive%20digitale%20Fotografie%20e.pdf

You may have also missed this info on the Schneider site that is also available today:

https://www.schneideroptics.com/ecommerce/CatalogSubCategoryDisplay.aspx?CID=202

And that was the whole point. Analog view cameras and lenses simply can not deliver the quality digital backs are capable of. A camera like a Linhof M679 series and digital lenses will deliver far greater quality.

Again, go look at what photographers like Steven Wikes are doing.

the answer is here.....

Equivalent Focal Length and Field of View

I wonder if the reason for special digital lenses is the same that some of the wide-angle Leica mount lenses needed to be re-designed. Digital sensors, which aren't simple flat receivers, but have real thickness with levels of different components that the light has to pass through, don't like light that comes to them at a steep angle. but film doesn't care. That isn't a problem in the middle of the image where the light is straight through, but is a real issue out towards the edges.

 

I suspect that non-retrofocus lenses, which put the back element very close to the film, are the worst offenders here. That category contains mostly non-SLR lenses, since SLR lenses were always designed to sit farther from the film to allow room for the mirror. RF 35mm cameras and view lenses didn't have that problem, and usually better non-retrofocus lenses are easier to build than retrofocus. I can easily see a situation where film LF lenses would not be optimal for digital, since the same problem has already happened in 35mm, and was dealt with through new specialized designs.

 

It wouldn't surprise me at all if the makers of LF lenses had faced the same problem. As for the lack of LF digital lenses in production, I guess everyone must have noticed by now that if you're shooting smaller formats that are quickly approaching 100MB, LF photography is an evolutionary dead end. Anything you could do in the camera now gets done in the computer, and is easier.

I think this was the link you intended to link to:

Sensor Stack Thickness Part III: The Summary

that also explains the sensor problems in developing newer lenses for LF. the other deals with crop factor, another overlooked fact in comparing digital lenses to analogue. focal length equivalents have more to do with image coverage and the size of the sensor regardless of media.

Did you see there is a 4x5 sensor coming? imagine the size of those files and the machinery you'll need to open them?

for now the scanning back makes sense but that's rather slow for most applications. when I first started thinking of scanning backs, I thought theyd do it more like focal plane shutters with the narrow sensor running by at 1/1000s. I once tried holding my scanner to the back of my 8x10 (digital dawn) but I never really did enough experimenting.

The issue with sticking a DSLR (of any size) on the back of a view camera, is that the sensor is recessed deeply in the body. This means that oblique rays from the view camera lens can't fully cover the sensor because they're obscured by the camera lens mount. So not much point in making a sliding back that pushes a DSLR into the corners of the 5"x4" frame.

 

However, the advent of slim bodied mirrorless digitals might change this situation and allow greater coverage.

 

5x4 film isn't cheap - true, but still cheaper for a small number of shots than any digital large format 'fudge' that's on the market.

 

FWIW, my reasonably priced Canon 9900 flatbed scanner allows 5x4 scanning at 4800 ppi. Although I must admit that the optical resolution doesn't quite match that. Even so, a 2400 ppi scan gets a fully useable image of around 9000 x 11000 pixels (100 megapixels), which knocks most DSLRs sideways.

 

In any case, the 5x4 gets mainly used for its movements, not for its size. So the number of megapixels isn't too relevant. And a rollfilm back would make it more economical to run.

 

"A 45 camera and large format analog lenses simply can not deliver optimal results with digital backs."

 

I thought we'd got past this 'throw away all your old film lenses; they're no good on digital' BS years ago. And what's an 'analog' lens?[/quote

 

Ken Rockwell has a post of a recent Yosemite El Captan shot. Click on it, and look at the edge between the mountain and the sky. My Nikon F.E. does a better job with Velvia, saying nothing about 4x5.

 

California's Eastern Sierra & Yosemite, October 2017 by Ken Rockwell

that also explains the sensor problems in developing newer lenses for LF. the other deals with crop factor, another overlooked fact in comparing digital lenses to analogue. focal length equivalents have more to do with image coverage and the size of the sensor regardless of media.

 

Did you see there is a 4x5 sensor coming? imagine the size of those files and the machinery you'll need to open them?

 

for now the scanning back makes sense but that's rather slow for most applications. when I first started thinking of scanning backs, I thought theyd do it more like focal plane shutters with the narrow sensor running by at 1/1000s. I once tried holding my scanner to the back of my 8x10 (digital dawn) but I never really did enough experimenting.

Paul,

after trying several backs on LF, that's the same conclusion I came to. The sensel size on the Dicomed Field Pro I have is in the sweet spot for the lenses I have, and it works wonders on the RB as well, though only a 6kx6k image @ 7x7 cm capture

erie

Hey Erie where ya been? Still hacking cameras?

Yeah its all about optimizing lenses to fit the sensors or film size. the sensors have their own problems to over come, so special designs are optimizing lenses specifically for digitals on small sensors.. BUT 70mm x 70mm is hardly the same as 102mm x 127mm.... a full 4"x5" format. So yes they are optimized for that sweet spot at their mid range and if you ever have a full 4x5 sensor, it would be optimized at the same f22 no doubt... that's just the physics of lenses. It would be nice if LF lenses were faster..

Its all relative to the formats they are designed for.