New "arTec" Sinar Architecture Camera

[ddk]

Son:

Right now I'd the two exceptions I'd consider are the Rollei Xact and the Linhof 679.

Cheers,

So you find the Rollei better made than the Arca Swiss? Could you elaborate a bit?

david

 

[Jack]

So you find the Rollei better made than the Arca Swiss? Could you elaborate a bit?

david

Not saying either is better made, just more rigid. Understand I used to shoot an Arca Swiss 4x5, the newest 141x141 F-Metric with micro-orbix, and I loved it! HOWEVER, because of the added movements, it is not as rigid between the standards as the two above, nor is focus as easily locked without moving the standard slightly as you lock it... For those two reasons I would choose theXact or Linhof 679 (NOT the Technikardan!) over the A/S, but understand both are also heavier and don't fold up as compactly as the A/S, so there is a trade-off...

Cheers,

 

[PeterA]

the Linhof is sexier - simple as that ...

 

[ddk]

because of the added movements, it is not as rigid between the standards as the two above, nor is focus as easily locked without moving the standard slightly as you lock it...

Thanks Jack, I get it now.

david

 

[shakeshuck]

Good question David, some of us have been shooting larger formats for a while and forget some of the basic concepts.

The simple answer is rigidity, alignment and parallelism of the standards. As you go down in format size, the focal length of lenses required to generate a given FoV (Field of View) also get shorter. As focal lengths get shorter, the amount of lens movement to achieve (or maintain) focus gets reduced.

So by way of example, let's say a 180mm lens on 4x5 film has an allowable focus error of +/- 0.5mm to retain a "crisp" appearing image. On MF digital, we would use an 80mm lens to render the same FoV, but the shorter lens maybe only allows for a focus error of +/- 0.2mm. As one can imagine, if the lens cannot be held to within the tighter tolerance, then you won't get a sharp image across the field. Thus the more rigid and precise the camera is to begin with, the better the final result.

So rigidity and parallelism are why for the most part, not many MF digital shooters are embracing the current selection of view cameras -- with a few exceptions, none are really precise or rigid enough to render optimal output with an MF back.

Cheers,

Jack,

Whilst what you say is correct, I doubt its relevancy in actual photographic conditions. Any subject usually has points in front and behind the focal point; it is highly unlikely that your image will run perfectly parallel to the DB plane (one exception to this is of course looking at a building head-on during architectural photography), but this is only relevant if the back IS perfectly aligned with the building, and adding tilt or swing negates the argument.

 

[jotloob]

Not saying either is better made, just more rigid. Understand I used to shoot an Arca Swiss 4x5, the newest 141x141 F-Metric with micro-orbix, and I loved it! HOWEVER, because of the added movements, it is not as rigid between the standards as the two above, nor is focus as easily locked without moving the standard slightly as you lock it... For those two reasons I would choose theXact or Linhof 679 (NOT the Technikardan!) over the A/S, but understand both are also heavier and don't fold up as compactly as the A/S, so there is a trade-off...

Cheers,

Jack

I use an ARCA-SWISS F-METRIC 6x9 with ORBIX and my CFV BACK attached to the ROTASLIDE adapter . I find the camera very stable and also very handy . I do not experience the "issues" you describe above .

I can also use the A/S with the 4x5 back (171) having the front board as 110 mm board . That makes a kind of view camera . But I would never use this combination with a digital back

Regards Jürgen

 

[ericstaud]

Jack,

Whilst what you say is correct, I doubt its relevancy in actual photographic conditions. Any subject usually has points in front and behind the focal point; it is highly unlikely that your image will run perfectly parallel to the DB plane (one exception to this is of course looking at a building head-on during architectural photography), but this is only relevant if the back IS perfectly aligned with the building, and adding tilt or swing negates the argument.

My real life example came when I got my 35mm digitar. When set at infinity the lens focused out about 50 feet from the camera. The horizon in a big landscape shot was definitely soft. The lens mount was off by 1/10th of a mm. If I remember correctly, this was shooting at f11.

The total travel distance of the 24mm digitar is about 1.5 mm.

There is something nice about the Alpa or Cambo cameras when you can go out on the job every day without a second thought of having focus problems. Adding swings and tilts to the camera means you have to add in methods to check focus across the whole frame on each setup very carefully. I think the big challenge for the new Sinar is to have the tilt mechanism stay perfectly accurate for at least several years of use and for it to be very easy to get the tilt back to zero without having to carefully check the entire frame.

 

[Jack]

My real life example came when I got my 35mm digitar. When set at infinity the lens focused out about 50 feet from the camera. The horizon in a big landscape shot was definitely soft. The lens mount was off by 1/10th of a mm. If I remember correctly, this was shooting at f11.

Exactly!

No way you can set focus to within 0.1mm using a ground-glass and loupe; you cannot even insure the GG is in the same plane as the sensor to within 0.1mm on a "sliding" or other moving back... To get a perfectly crisp image, you need digital focus confirmation of some type. The next best alternative is a fully rigid assembly where focus has near-zero back-lash and has been calibrated.

My example was with a 210 lens where 0.5mm made the difference between 30 feet and 350 feet being the exact focus point at f22! FWIW, moving a standard 0.5mm on ANY view camera is literally a "touch" on the focus knob, and most will not hold that position precisely while focus is being locked down.
~~~

What we can debate is whether that amount of shift and corresponding "softness" to the main subject area of you composition is important to the final image. In most cases it probably is not, but the fact that I know it is there drives me absolutely nuts :banghead:

Here is an example of the narrow DOF's we are talking about being visible with high resolution digital. This shot is from a 22MP ZD back -- note that it is not a great image, just a good example of the tiny DoF's you may have to deal with. Here a few mm of camera movement either direction would have been visible, which probably translates to less than 0.01mm of lens focal distance change... (The flower is only about 30mm in total diameter, the yellow stamen inside maybe 2mm...)

Full image:

Red crop area at 100%:

 

[David K]

Jack, your post illustrates quite well the extremely narrow DOF issues we face in the MF arena. With regard to digital focus confirmation, my experience has been that it's not yet precise enough (especially at close distances) to resolve this difficulty. I find myself relying more and more on manual focus if a crisp image is desired. With my less than perfect eyesight a big bright viewfinder is essential to achieve this.

 

[rainer-v]

I think the big challenge for the new Sinar is to have the tilt mechanism stay perfectly accurate for at least several years of use and for it to be very easy to get the tilt back to zero without having to carefully check the entire frame.

yes i know that and it was one of the major points on the feature list that swing and tilt ONLY can be built in the system, if there is a simple system to set it 100% accurate to zero, without that there is any need to check focus.
this will not be a problem.:salute:

 

[ericstaud]

yes i know that and it was one of the major points on the feature list that swing and tilt ONLY can be built in the system, if there is a simple system to set it 100% accurate to zero, without that there is any need to check focus.
this will not be a problem.:salute:

I am glad to hear you think it will not be a problem Rainer.

 

[Jack]

With regard to digital focus confirmation, my experience has been that it's not yet precise enough (especially at close distances) to resolve this difficulty.

I may be extremely lucky, but I have found the focus confirm on my Mamiya AFD2 body with both the ZD back and my P45+ back to be spot on -- at least a lot closer than I could ever get by eye. I am hoping my new AFD3 body is as good

Cheers,

 

[David K]

Jack, I am NOT going down this road again

 

[Jack]

Jack, I am NOT going down this road again

LOLOLOL!!! I hear you on that loud and clear. All I was saying was I have it so good now I'm reluctant to change anything, even within the existing system!

 

[jlm]

when i work out the math, using a 210mm lens, 35' lens/object distance would have a lens/image distance of 214mm;
350' lens/object would be 210.5. so the focus difference would be about 4 mm for objects between 35 and 350 ft using a 210 lens.

using a 35mm lens, the distances are 36.14mm for 35'. 35.11mm for 350 ft, or a delta of about 1mm.

 

[Jack]

John: I tested this empirically with a 210 lens on the camera, and the difference was as close to 0.5mm as I could measure on the focus rail. It may be the difference beteween a "pure" 210 and a 210 telephoto design lens...

 

[thsinar]

For those looking for a confirmation, it is now on Sinar's webpage:

http://www.sinarcameras.com/site/index__0-e-2019-50-2158.html

Best regards,
Thierry

 

[Jack]

yes i know that and it was one of the major points on the feature list that swing and tilt ONLY can be built in the system, if there is a simple system to set it 100% accurate to zero, without that there is any need to check focus.
this will not be a problem.:salute:

Rainer:

On a side note... I have always been a huge fan of camera movements, used them all the time on large formats. However, a friend and fellow photographer who also used to exclusively shoot 4x5, and who recently came to a high resolution MF back, has started to use digital focus blending instead and claims he prefers it to tilt and swing. I was skeptical, but I've seen the images and am pretty impressed. The main advantage I see is he is not restricted to a tilted plane of sharp focus as we are with tilts, but rather he can select the components or regions from foreground and background he wants in focus at the blend... He will generally compile 3 to 7 frames of the same subject just altering focus point between them to gather his set of images for the later blend...

I have not gone there myself yet, but intend to try it on my next major outing so I can determine if it is a viable option for me. I am curious to hear if anybody else here has tried it?

Cheers,

 

[jlm]

1/fL=(1/image dist) + (1/object dist)
should apply, as that formula is what really defines focal length (object dist is infinity then image dist = fL)

jack: I did try the Helicon focus; see attached image from 5 focus brackets; this would have been a textbook swing condition. processing is very fast. watch out for moving bushes, etc., he, he

 

[thsinar]

Yes, Jack, another interesting possibility.

Possible with any camera.

As a side note: the Sinar Hy6 has an automated "focus bracketing" feature.

Best regards,
Thierry

Rainer:

On a side note... I have always been a huge fan of camera movements, used them all the time on large formats. However, a friend and fellow photographer who also used to exclusively shoot 4x5, and who recently came to a high resolution MF back, has started to use digital focus blending instead and claims he prefers it to tilt and swing. I was skeptical, but I've seen the images and am pretty impressed. The main advantage I see is he is not restricted to a tilted plane of sharp focus as we are with tilts, but rather he can select the components or regions from foreground and background he wants in focus at the blend... He will generally compile 3 to 7 frames of the same subject just altering focus point between them to gather his set of images for the later blend...

I have not gone there myself yet, but intend to try it on my next major outing so I can determine if it is a viable option for me. I am curious to hear if anybody else here has tried it?

Cheers,