Added movements to my Korona View

[Rafael Garcia]

I am almost done with my modified lensboard that allows my old Gunlach Korona View 5x7 to swing and tilt. All I have to do is test it for light leaks/function with film. Then I will finish the faceplate with etched copper. It looks like it may do a great job from my dry run testing....

http://i67.photobucket.com/albums/h285/ragc01/5x7%20Korona%20Photos/Dsc00008s.jpg
Now I can do what the Big Boys do!

http://i67.photobucket.com/albums/h285/ragc01/5x7%20Korona%20Photos/Dsc00016s.jpg
Snakin' around...

http://i67.photobucket.com/albums/h285/ragc01/5x7%20Korona%20Photos/Dsc00022s.jpg
I need to do something with that faceplate! Probably etch a design in copper and cover the nasty plywood up.

http://i67.photobucket.com/albums/h285/ragc01/5x7%20Korona%20Photos/Dsc00025s.jpg
Very simple construction with no modifications to the camera itself: four bolts with strong springs and knurled knobs, baseplate frame. faceplate(lensboard) and a short bellows inside the springs (to avoid lightsealing the bolts). You tighten the 2 bolts on the side you want to move back, to any degree you want. The lensboard holes are oversized to allow the lensboard to twist around.

Next: new back using a Graphic View I 4x5 back and adding back shift/rise.

[Rafael Garcia]

Thought I'd post a photo of the finished lensboard. Stained to match...

http://i67.photobucket.com/albums/h285/ragc01/5x7%20Korona%20Photos/Dsc00033s.jpg

[Bob Gentile]

Your workmanship looks beautiful. When are you going to run some film through it?

[Ralph Barker]

It looks very nice, Rafael. The brass hardware fits right in with the overall appearance of the camera.

[Doug Howk]

Rafael, I really like your design (& workmanship). I need to make an extended lensboard for my 19" Artar on a 7X17 Korona. Instead of just a simple extended box, I think a variation of your design should enable me to also add movements (longer bellows and brass tubes & springs at the corners). Thanks for the idea.

[Rafael Garcia]

Your workmanship looks beautiful. When are you going to run some film through it?

Thanks all! It's raining cats and dogs over here, so any shooting of film has been postponed until next weekend... I've been working on my reduction back instead. Nothing new there, just building a matching wood back with a Graflex Graphic View I back I found cheap attached to it. It's ready exept for final fitting/lightproofing and the pins. I did not add the shift function as the amount I could get was not worth the trouble of the extra light seals and hardware. This back will ensure I can use the camera when they come take away my 5x7 film!

[Andrew O'Neill]

Cool! That's kind of what I did with my copy camera-converted to 8x10 enlarger's lens board...but yours is much much better than mine. Let us know how it performs, eh?

[GPS]

With four screws in a square corners how do you make it sure that the tilt/swing is done strictly around a horizontal/vertical axis and not around a "floating" axis?

[Rafael Garcia]

Not easily... The bolt lengths are absolutely equal and the lensboard is flat. The bolts are equally spaced from the edge and the lensboard is centered. It follows that if the bolt nuts are the same number of turns from the end of the bolts on each side of the board (the two on the tighter side and the two on the looser side equal to each other) the axis is a vertical or horizontal axis (depending on if it's swing or tilt) on the plane equidistant from the "inside" end of the knurled nut to the same point of the opposite knurled nut. Both axis are in line with the the ray from the center of the lens' diameter to the center of the ground glass. I have not measured these distances exactly, but it can be done. If the nuts are adjusted randomly, then the axis is somewhere in that space, but it is much more difficult to determine, and it becomes a "floating axis". Now, since I'm new to LF and all of this twisting and turning, please educate me: Why does it matter to an amateur where the axis is, as long as he/she can get the image composed in the ground glass? I can see the relevance in very technical, scientific photography, but it's not something I think, in my newbiness, is important to my purposes. I don't mean to be ironic here, I really am interested in learning about this.

[GPS]

First the technical point: even if the screws are of the same distance from the center etc. and you try to turn them the same amount (but heck, one would need to count its turns and maybe write it down and without any sign on the screw you will never know exactly where you are with each screw) it still doesn't make for a firm axis - the hole around the screws has some will and the lensboard moves in it. To make it a precise movement the lensboard would need its own axis - precisely like a normal lensboard.
The practical point: If you move the lensboard with a "floating" axis you cannot keep the plane of sharp picture on the gg as you wish it - it will show some random variations. That's why the standards must be on a firm axis.
Your solution would show its shortcomming especially with short focal lengths. Good luck!

[Rafael Garcia]

I'm sure you are right, GPS. Then again, I will let you know how it goes after testing. As for counting turns, it is not necessary. I carry my small tape measure for calculating bellows compensation...all you have to do is pull it out and measure the distance each nut travels down the screw to know the axis is vertical or horizontal with a degree of precision.

Your argument is valid based on absolute precision. Most things are not that precise, and we are quite satisfied with them. I could have gotten involved in my original design, with vertical and horizontal axis, and all the precision manufacturing that would have involved. I'd still be working on it, correcting imprecise metal bends, off center holes, etc. The result would have been heavy, wobbly, would have had built-in mechanical imprecisions inherent to it's home-built character. This design avoids all of that. It's beauty is that it is a solid lens platform, not depending on connections for it's strength. It can be made very easily by anyone without special tools, and there is no need to be more precise than what can be measured with a common ruler.

I am pretty sure the results will not be dissapointing, and will post them here. After all, one of my requirements was to achieve the movements without modifications to my camera. The old fixed lensboard is still around, and if this were to be a total disaster (doesn't look like one through the ground glass right now) then I'll just simply pop it back on, no harm done and only a few hours and a couple of dollars wasted. I'm happy to spend the time and money if I learn something from the small investment.

Thanks for the advice, I'll keep it in mind as I test.

[JackG]

I think your approach is ingenious and applicable to a lot of the older view camers that are light and pretty it use but limited in movements. Well done! Thanks for passing the idea on. And, I expect the lack of precision is no more troublesome in use than it is on the back of a Linhof Technika

Jack

[Rafael Garcia]

I finally got away and ran a quick test of the movements. The following contacts have not been manipulated except for the scanning on my computer's HP psc 1350 All-In-One scanner (not a high res photo scanner). I have not corrected the exposure, sharpness, etc.

http://i67.photobucket.com/albums/h285/ragc01/5x7%20Korona%20Photos/scan0007.jpg

The top, slightly over-exposed image was a 2 second exposure at f32, no movements (timed with my watch, could have been slightly longer).
The bottom image was between f22 and f16, 1 second, full left swings front and back.

Tentative conclusions:

1) Not enough visible difference to merit much comment on swing - perhaps I didn't pick the best testing angle for this (lack of knowledge). I had to measure the lengths of the sides in the contact prints (the tripod was stationary) to tell there was a difference. It is most visible in the relative position of the trees to the right of the cabin.

2) Don't see a problem with sharpness in the full swing shot. The axis of the lensboard may be "virtual", but it appears to be predictable and controllable.

I am keeping the movement lensboard for now, until it proves itself a problem.