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Author Topic: Linhof Techno, can you really focus with it?  (Read 11030 times)
torger
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« on: February 25, 2012, 05:20:20 PM »
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Linhof Techno seems like an interesting MF tech system for cost-sensitive amateurs like myself since lenses can be had realtively low cost (Schneider Digitar) compared to ALPA or Arca-Swiss R-Line.

What I don't understand is how Linhof claims focusing ability that no other bellows camera does. While for example Arca-Swiss say that less than 45mm is not suitable for their bellows cameras due to precision issues (they recommend R-Line), Linhof says 23mm is ok with the Techno (I would not use shorter than 35mm myself though).

It's not only the wide angles, it's also about the ground glass -- can it really be used for critical focus? Or do you need ALPA-style distance-calibrated focus rings and laser distance meters? Lets assume a world where there is no live view on the digital back, since that is where I'm going to be if I enter MF digital.

Anyway, my educated guess from all theory I know is actually that the Techno should probably work. But when I read about MF digital for landscape photography it seems like a lot of stuff is about difficulty focusing. I grasp all the technical aspects, shimming, micrometric precision required from optics etc, but still it makes me wonder at which apertures people are shooting, and if the ground glass really is unusable for final focusing.

Say shooting individual flowers with a short DOF I guess you'd probably want to check focus on a large screen preferably. But larger landscape scenes, I was thinking that in 99% of those cases you'd use an aperture say f/8 - f/11 and focus at a distance such that DOF is sufficiently large so minor focus errors would be masked, and thus it would be possible to use a loupe on the ground glass and make as sufficently good focusing. In other words, that all the talk about how difficult it is to focus MF systems is a bit exaggerated. But perhaps the ground glass is too grainy to see good focus or impossible to get sufficiently well-matched with the back?

If that would be the case the Techno seems pretty unusable without a live view back.

I've read Joseph Holmes interesting articles http://www.josephholmes.com/news-medformatprecision.html and http://www.josephholmes.com/news-sharpmediumformat.html and from those MF, especially tech cam systems, seems pretty hopeless to get perform well. But on the other hand he seems to be extremely picky about quality, expecting full corner-to-corner sharpness at maximum aperture, something I'm not used to demanding in the 35mm world...

With the live view on 35mm digital I've never felt the need to have a distance scale on the lens, except for certain focus stacking situations, but in those cases I've solved it by focusing on objects in the scene at different distances. I never set the lens to infinity or hyperfocal etc, I always focus on something. So if the ground glass can be made to work similary to a live view, I'm good.

Has anyone used the Techno and has anything to report about focusing?

(If someone wonders why I ask stuff all over the place about 4x5" film, digital, stitching etc, the reason is I'm investigating several options to get to a more view camera-like workflow with high resolution potential, which suits my photographer's personality better than running around with 35mm digital and tilt-shift lenses.)
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theguywitha645d
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« Reply #1 on: February 25, 2012, 05:28:12 PM »
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I use a Phase One P25+ on a Linhof C679 which I believe has a very similar focusing mechanism and ground glass with 55mm and 90mm lenses. I don't have any focusing problems. BTW, focus tolerance is a product of the aperture, not focal length--it is related to depth of focus (not depth of field).
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Gigi
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« Reply #2 on: February 25, 2012, 06:17:49 PM »
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Very interested in this exact subject as well, for the same reasons. The Techno seems to offer 4x5 LF technique and flexibility with digital back tolerances - raising the question: does it really work that well? The OP seems to suggest landscape work, not nec. table top, and it would seem f8-11 would do the trick just fine. Again, anyone with real-world experience?
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Geoff
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« Reply #3 on: February 25, 2012, 09:09:16 PM »
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I, too, have had an on-going curiosity about the Techno.  The whole sliding back "thing" where you compose your shot and then slide the digital back into place seems unwieldy and awkward, but several accomplished LF photographers have produced beautiful work with the process.  Look into Joe Cornish and search out some of his comments on some other forums or blogs.  He used Ebony 4x5 gear for quite a long time, then transitioned to MF digital via the Techno and apparently still uses it for certain kinds of landscape shooting.  I've corresponded with him before, directly (through his website connection) and he's proved to be a thoughtful, helpful person.
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theguywitha645d
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« Reply #4 on: February 25, 2012, 10:14:24 PM »
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I use the sliding back on my Linhof. It is easy once you get used to it. It doss take make the camera wide and I have to remember to lock my swing--not a problem with the Techno, I understand. But it is quick to use.
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torger
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« Reply #5 on: February 26, 2012, 02:56:08 AM »
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I use a Phase One P25+ on a Linhof C679 which I believe has a very similar focusing mechanism and ground glass with 55mm and 90mm lenses. I don't have any focusing problems. BTW, focus tolerance is a product of the aperture, not focal length--it is related to depth of focus (not depth of field).

It is two parts, one is tolerance (which indeed larlgly is a depth of focus issue) the other is how possible it is to move the lens to the desired position through the available controls (gear on focus rail) and feedback (ground glass)

If I've understood things correctly, a 24mm lens has only about 1.6 mm distance on the rail between some sort of near limit and infinity. I was thinking that the focus rail (is that the right term?) on the Techno would have two knobs, one for large adjustments for tele lenses, and a fine-tune gear for the wides. But there is only one knob to turn as far as I know, and 1.6 millimeter would be a fraction of a turn, say (15 degrees or so). Having used geared macro rails for my DSLR I think that it can be good enough though, if gearing is high quality and feedback is good (you can see where focus is) you can with sufficent precision nail the focus even if the whole range is within less than a quarter of a turn.

Concerning depth of focus, approximately 2 * <f-number> * <max acceptable CoC>, a typical value would be something like 2 * 8 * 8 = 128 microns, if you relate CoC somewhat to diffraction and sensor resolving power (I think having the CoC somewhere inbetween pixel size and Airy disc would be suitable guide). Achieving a repeatable sub-0.1 mm match between ground glass and sensor would not be too hard, assuming you can adjust with shims?
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torger
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« Reply #6 on: February 26, 2012, 03:29:48 AM »
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I found this thread:
http://forum.getdpi.com/forum/medium-format-systems-digital-backs/29341-no-love-linhof-techno.html

Seems like for some focusing is a big issue, especially those that have not used it Smiley, while it works fine for others. And many think you'd preferably have live view on the back instead.

It does seem like the Techno may be stuck in the very very small niche for those that can afford a digital back but not the expensive lens systems of Arca R-Line and Alpa. Even if the Techno works it is so much uncertainty around it that you'd choose Arca/Alpa if you can.
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ErikKaffehr
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« Reply #7 on: February 26, 2012, 04:01:15 AM »
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Hi,

This is an important point often missed. Josep Holmes misses it and also does Lloyd Chambers.

See it this way. If you defocus the sensor 0.1 mm the circle of confusion caused by that defocus will be 0.1/f-stop mm, with f/8 it wil give a CoC of 12.5 microns.

Best regards
Erik


BTW, focus tolerance is a product of the aperture, not focal length--it is related to depth of focus (not depth of field).
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dwhistance
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« Reply #8 on: February 26, 2012, 06:12:08 AM »
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If it's any help I've just spent a week with Joe and watched him using his Techno.  He is slower using it than he was with his 4x5 but clearly doesn't have any problem with focus, or indeed dialing in swings and tilts.  I've also printed some images for him which I can confirm are stunningly sharp at very large sizes.

As a 4x5 photographer myself I am interested in the Techno as a route into digital MF but was concerned about all the comments on focusing digital backs.  Having seen Joe in action I am inclined to dismiss them , however it should be said that Joe is a master technician and has had more practice with view cameras of all sizes than almost anyone.

David Whistance
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Gary Ferguson
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« Reply #9 on: February 26, 2012, 08:15:42 AM »
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I've used a Linhof M679cs with Phase One digital backs for several years now, starting with the P25 and after several upgrades I'm now using the P65+. I use it both with a Linhof sliding carriage and also by attaching the back directly to the body.

Focusing, especially with lens movements, is okay, but no better than okay. I'm looking forward very much to the arrival of a medium format back with fully functioning live view (as opposed to the IQ180 system which simply doesn't refresh quickly enough for focusing purposes).

The problem's easy enough to understand. When I used 4"x5" film I almost never enlarged more than x6 or x7. But with a digital back I'll sometimes enlarge x15 or x20. It's easy to use a x6 loupe on a focusing screen, but you can't really use a higher magnification loupe than this without the image becoming lost in the grain of the ground glass. Consequently critical focusing becomes an article of faith at large magnifications. Personally I've never found any real difference in the accuracy (or lack of it) between lenses from 35mm to 120mm, vignetting on wide angles adds to the problems but not insurmountably so, for me the key issue is the inadequacy of ground glass focusing for very large enlargements. I get by with it, and continue to use the system, so it is useable. But IMO live view will be a huge step forward for digital backs and technical cameras.
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Gigi
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« Reply #10 on: February 26, 2012, 08:50:22 AM »
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If it's any help I've just spent a week with Joe and watched him using his Techno.  He is slower using it than he was with his 4x5 but clearly doesn't have any problem with focus, or indeed dialing in swings and tilts.  I've also printed some images for him which I can confirm are stunningly sharp at very large sizes.

As a 4x5 photographer myself I am interested in the Techno as a route into digital MF but was concerned about all the comments on focusing digital backs.  Having seen Joe in action I am inclined to dismiss them , however it should be said that Joe is a master technician and has had more practice with view cameras of all sizes than almost anyone.

David Whistance

Can you elaborate on how the care in the technique has influenced the focusing part of this puzzle? Is it a question of DOF calcs, and using tilts carefully, or more than that for  the focusing aspects - as the care in composition, compiling, printing, etc.. is a different matter.

One wonders if focusing for landscapes and urban shots is good enough with the GG, and if for closer subjects, use of the helical mounts and some disto-meter is needed, or tethering? Is that a fair appraisal?
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Geoff
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« Reply #11 on: February 26, 2012, 09:01:38 AM »
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It probably depends a lot on the user of such a camera, his experience, and his eyes. (Some of my assistants, they're 10-15 younger, get sometimes better results once they're used to a camera, than I do, I'm only 35 :-/)
I sold my old Flexicam, which is kind of similar to the Techno, because to standard screen was quite dark with the 35 Digitar. The real probelm for me was the risk to focus beyond infinity. Longer lenses were not problematic, and i used it on location too with a 72 and 100mm Digitar.
I now use the Bicam II which is maybe an alternative for some people:
YOu can choose if you want to use it ass a technical pancake camera or a bellow camera. You then mount your lenses on a normal lensboard or a board with focusing ring.
For wide angle, i choose to mount my 35mm with a focusing ring. The camera is then quite similar to a Cambo or Alpa SWA. It only shift up/down. unfortunately. For others lenses, i fix a bellow unit on the body, and the camera then gets side shift, tilt and swing movements and is then similar to the Techno.The lenses are then on a simple board.
One nice advantage: You can switch between a sliding back (still problematic with the 35mm) or mount the back directly to the body(and use a small viewfinder).
Vieri, he is on the GetDpi Forum, I don't know if he's here too, has used both cameras with amazing results.
I  had a look at the Techno at the Photokina last time, it is amazingly well build, but i had found a Bicam at an very good used price and had already my lenses on the right boards too.
You probably should try the techno yourself if it suits you. I think the Techno and the Bicam (and the Artec too) are very good alrounder tools, but there are always better solutions for studio-only guys or architecture-only guys.



Tom
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MHFA
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« Reply #12 on: February 26, 2012, 11:42:17 AM »
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The Techno is an allrounder, the Artec no. Architecture or landscape, for other uses I would prefer other system.

Michael
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torger
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« Reply #13 on: February 26, 2012, 12:43:07 PM »
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I come from the 35mm digital world. My "tech cam" today is a Canon 5D mark II with a 24mm TS-E lens, which is about as good as it gets for DSLRs.

Anyway, manual focusing in my world is as follows:

  • Never ever use the distance scale on the lens, it's not precise and not meant to be, manufacturing costs are held down by not having trusty distance scales. Oh, there is no such thing as an infinity stop, turn the lens maximum and it is out of focus. This means that you always focus on something in the scene.
  • Never expect corner-to-corner sharpness of a lens wide open, the best compromise diffraction vs corner-to-corner sharpness for most lenses is f/8. If your picture don't need corner sharpness f/4 or f/5.6 is probably best resolution-wise.
  • If it is too dark to focus on live view, you're blind. You'll have to guess using those poor distance scales or bring out a flashlight and light up something to focus at. Trial-error long-exposure high ISO shots and review before taking final shot. Fortunately live view has good ISO performance so one rarely gets blind. Seeing tilt on live view requires more light than focusing. If tilt is hard to see, one can in many situations successfully use a tilt preset based on experience
  • The hyperfocal concept is sometimes used, but not on the distance scale, but in the way that if I focus somewhere inbetween hyperfocal (aperture-dependent blur spot size, the traditional hyperfocal with fixed CoC gives you blurry infinity) and infinity you get more near-DOF than putting it directly on infinity, and the tolerance is huge. If hyperfocal is at 30 meters and you focus at 60, your near DOF goes from 15 meters to 19, which still is better than 30 which you get if you focus at infinity.

The purpose of listing this is to show that if you come from the 35mm digital world you perhaps don't have that high expectations. If you come from the ALPA world and use laser distance meters and lens distance scales, clearly the Techno will not look good. If you come from 4x5" large format, perhaps the small ground glass feel awkward.

But if you come from the 35mm digital world, perhaps it is not too bad? I guess it depends on how ground glass with loupe works in comparison to a modern DSLR live view. No doubt the live view is better in low light situations or verifying focus in shadowy areas. But perhaps the ground glass is good enough for most situations...?
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darr
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« Reply #14 on: February 26, 2012, 02:37:14 PM »
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In controlled situations like the studio and perfect weather days outside, I have no problem focusing on the GG with my Arca M Line 2 and my Alpa Max, but when I do not have these situations, focusing can be a challenge. I do not own a Live View back (yet), but I have been able to work with what I have. I personally do not find it that much harder to focus on the 645 GG when compared to the 4x5". I think once I developed focusing with the 4x5" over 25 years ago, I carried the technique over to the 6x9 film backs and then to the 645 GG. Practice makes perfect?
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darlene almeda
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torger
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« Reply #15 on: February 26, 2012, 03:32:22 PM »
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In controlled situations like the studio and perfect weather days outside, I have no problem focusing on the GG with my Arca M Line 2 and my Alpa Max, but when I do not have these situations, focusing can be a challenge. I do not own a Live View back (yet), but I have been able to work with what I have. I personally do not find it that much harder to focus on the 645 GG when compared to the 4x5". I think once I developed focusing with the 4x5" over 25 years ago, I carried the technique over to the 6x9 film backs and then to the 645 GG. Practice makes perfect?

Sounds promising I think... Smiley

I have both high and low expectations. If it was just about the function, I'd probably be satisfied with juuust slightly better than unusable Smiley. But I don't like the concept of paying €6500 for a camera that barely works, if that would be the case.
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Christoph C. Feldhaim
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« Reply #16 on: February 26, 2012, 04:00:59 PM »
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The Techno was designed from ground up to be used with a digital back.
It doesn't make sense if you want to shoot film as I saw in the other thread.
For film you can get incredible IQ with inctredibly less money.
For a non pro if you don't have a lot (really a lot) of spare money to spend it is not really justiyable  to not use film with a view camera.
I am going the same route, and for me after a lot of reading and asking it will be an Arca Swiss F micrometric orbix with three or four lenses.
You can get such a kit in good shape and with excellent lenses for around 5000 Euro if you look a bit.
For digital you can easily pay 6-8 times as much.
I didn't count in the scanner so far, but still ...
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torger
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« Reply #17 on: February 26, 2012, 04:26:58 PM »
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The Techno was designed from ground up to be used with a digital back.
It doesn't make sense if you want to shoot film as I saw in the other thread.
For film you can get incredible IQ with inctredibly less money.
For a non pro if you don't have a lot (really a lot) of spare money to spend it is not really justiyable  to not use film with a view camera.
I am going the same route, and for me after a lot of reading and asking it will be an Arca Swiss F micrometric orbix with three or four lenses.
You can get such a kit in good shape and with excellent lenses for around 5000 Euro if you look a bit.
For digital you can easily pay 6-8 times as much.
I didn't count in the scanner so far, but still ...

I'm evaluating several options. The only thing I do know is that I'm not perfectly happy with the 35mm digital for my landscape work, and is looking for alternatives.

A Linhof Techno starter kit with a second hand P45+ and one lens can be had for about €18K. Schneider digitar lenses cost typicall €1K - €2.5K, similar to pro 35mm lenses. I actually may start off shooting 6x7 rollfilm, with the digital Techno and a digital lens (the 47mm) or two, sitting around waiting for a decent digital back second hand deal. Or I get one of those ancient tethered 22 megapixel backs as a starter for €2K and make a cumbersome but working laptop portable solution. I plan to invest over 3 years or so, so it is a big decision. Probably as much second hand stuff I can get, possibly buying stuff in the wrong order so I may not have a usable system to start with, but I have my 35mm digital in parallel.

The toughest starter cost is the camera itself, unfortunately not so easy to get second hand like older film cameras.
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Satyajit
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« Reply #18 on: February 26, 2012, 05:08:16 PM »
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Getting a techno with IQ180 this week. With SK lenses.
Will do a few practice and test sessions and update shortly.
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torger
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« Reply #19 on: February 27, 2012, 12:54:14 AM »
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Getting a techno with IQ180 this week. With SK lenses.
Will do a few practice and test sessions and update shortly.

Exciting.

From the comments so far it seems like it indeed works ok, but there are some limitations with the GG. Wide angles are darker, especially in the corners and at some point it will become almost impossible to focus. Say if a 35mm only can be focused in full daylight and then only in the center of the picture, that would feel very limiting for me.
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