Model Photography/Scheimpflug Principle

[Charles Green]

For this post , I am placing cameras in the category of "Shop Tools". 

 

Recently, I came across a topic from 2013 addressing the depth-of-field problem encountered when photographing a vessel's hull from an oblique angle.  Kathy Teel has recently submitted a number of photos of outstanding models in this site's "Images" section.  Her last photo (as of 12-13-20), depicting a hull's port, stern section, illustrates the depth-of-field problem I am referring to.  This problem is independent of lens quality or the photographer's skill - it is an optical fact-of-life and stopping a lens down will not overcome it.  The close focusing distances encountered in model photography exacerbate the problem. 

 

Electronically manipulated "focus stacking" was the solution discussed in 2013, but there is another way.  An articulated camera/view-camera or an articulated lens fitted to a conventional camera can do the same, if not better job as focus stacking, while allowing a lot more freedom in camera position and composition.  And, you can see what's going on in the viewfinder - what you see is what you get.

 

Film view-cameras are still in production by several makers, as is sheet film, but not everyone is interested in film photography, as I am.

View-cameras with electronic backs - in place of film - are available but their price is astronomical.  However, If you own any F mount Nikon (film or electronic) or any EF mount Canon, both makers provide what they refer to as TS (Tilt - Shift) lenses.  TS lenses can achieve the same photographic effects as a view-camera. 

 

Both makers provide TS lenses in a wide range of focal lengths.  In the past, Pentax made a 24mm, K mount TS lens.  They come up in the used market.  And there are TS adaptors.  Adaptors can couple any lens and camera, but - Any lens used for tilting or shifting must be designed to project an image circle wide enough to cover the film or electronic sensor when the lens is used off-axis.  Conventional lenses are not made to do this.  "Lensbaby" makes a number of lenses and articulated mounts.  I have no experience with them and cannot speak to their optical quality.  They cover a range of camera mounts and offer a relatively inexpensive way into TS lens use. 

 

View-cameras and TS lenses allow the lens to be tilted/turned off axis, relative to the film/sensor.  In short, this brings the Scheimpflug Principle into play and solves the depth-of-field problem.  The shift function allows a lens to be shifted laterally, moving the image in the view-finder without moving the camera - but, not of much importance to this discussion.  The Scheimpflug Principle also allows correction of distortion inherent in photographing long, narrow objects (like ship's hulls) that seem to converge to a point in the distance.  Lines converging in the distance can be brought parallel, if you want.  The film/sensor must be able to be tilted relative to the lens to achieve this and this is where view-cameras come into play.

 

The depth-of-field problem is an optical fact-of-life, as is its solution, the Scheimpflug Prinicple.  It has been in use since its discovery by Austrian army Captain Theodor Scheimpflug in 1904, for correcting distortion in WWI aerial surveillance photos taken from an angle.    

 

    

 

 

 

 

 

      

[Charles Green]

I must amend my last paragraph.  World War I began in 1914.  Scheimpflug began using his method in 1904, during Austria's War of the 3rd Coalition on surveillance photos taken from observation balloons. 

[kurtvd19]

I haven't used a view camera in a long time.  Got rid of my darkroom when I concluded that spending time in it took time I could be shooting so farmed the darkroom work out to the pro lab and concentrated on the photography.  Sold the 4x5 and the RB67 just in time before you couldn't give away film cameras (and a 4x5 digital back is just too much cash.   Anybody want to buy a few Canon F1's and a bunch of Canon lenses (that don't work on my digital Canons)?

 

Enter the digital age and knowing the limitations of a TS lens decided that focus stacking was the way for me to go.  A bit of hassle but it does work.

Kurt

[Bob Cleek]

2 hours ago, kurtvd19 said:

Anybody want to buy a few Canon F1's and a bunch of Canon lenses (that don't work on my digital Canons)?

I'll see you  your Cannons and raise you my Nikon F Photomic head system and later Nikon 35mm's. Then there's the Leica screw mount stuff I inherited from a friend. The whole cased system, less the IIIg body. My 120 format cut and roll film cameras are gone, but I still have the darkroom equipment for them and a 70+ year old Solar bellows enlarger. I wish I knew some kid that wanted to get into doing their own B/W processing. I can't bring myself to donate it all to Goodwill and I'm too lazy to off it on eBay. I keep telling myself film is going to come back like vinyl LP's are.    

[Dr PR]

Anyone want a complete Nikon F3 system with a selection of focus screens and a 6X vertical viewfinder that replaces the pentaprism?

 

The two rail bellows attachment allows the lens to be shifted side to side and rotated a bit to accomplish the effects Charles mentions - to a degree.

 

I have used it with Nikon digital bodies, but everything is totally manual.

 

Photo stacking does work, and I don't find it to be much more trouble than editing ordinary photos. This picture was made with 12 stacked photos. The model is 22.5 inches long from the tip of the bowsprit to the ends of the boat booms on the stern, and it is in focus the entire distance! The pictures were made with a Nikon Micro Nikkor 105 mm f2.8 macro lens at f25 and 1 second.

 

 

However, all is not perfect. I did the stacking in Photoshop and it did get confused at the lower left. Looking at the plank edges you can see where it  picked the wrong images and the edges are  out of focus. Still, a 22.5 inch depth of field would be very hard to get any other way.

 

Another way to get an extended depth of field is to use a long focal length lens and photograph the object from a long distance with a small diaphragm opening (large f-stop number). You will need a lot of light and a lot of room to set up the shot.

 

Edited December 14, 2020 by Dr PR

[Dziadeczek]

Some time ago I took this pic of my (unfinished) model of the Rattlesnake, using focus stacking and Photoshop. It works.

[P_Budzik]

Having grown up with film and large format, I can understand the nostalgia and romance.  But especially for images destined for the net, I think a good dslr or mirrorless is more than adequate.  For focus stacking, I like Heliofocus over Photoshop.  The final image from Heliofocus can be easily squared up in Photoshop

 

The last segment of this video shows the automated features of Heliofocus ...

 

 

https://youtu.be/yXOsZVbclPI

 

Paul

 

Edited December 15, 2020 by P_Budzik

[Charles Green]

Dr PR's remarkable, focused-stacked, near head-on photo would be hard to duplicate any other way.   The photo was taken at a very shallow angle.  Employing the Scheimpflug principle  would require an extreme amount of lens tilt, maybe more than is possible.

 

P Budsik's reply echos most others in that a DSLR is more than adequate and the digital image is superior for reproduction on the Net.  I acknowledge that the electronic image is here to stay.   But, the fact that any F mount Nikon or EF mount Canon - DSLRs included - can be used with their respective makers TS lenses to produce the desired effect - in-camera, with a single exposure - seems to have gotten lost in the shuffle.  It's all done in real time.  What you see in the view-finder is what you get.  

 

With a TS lens on a DSLR, no time is spent with the tedium of accumulating the individual images needed for focus stacking and no time is spent later on at a computer arranging them.  Taking the series of exposures necessary for focus-stacking requires an undisturbed location.  Some locations may not allow this condition to be met.

 

While TS lenses use a method developed in 1904, they offer a time-tested, practical solution to the depth-of-field problem.  They are also very useful in architectural and landscape photography.