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  #61  
Old December 19th, 2011, 11:15 PM
Asher Kelman Asher Kelman is offline
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Default "Sweet Spot of Lens"

Quote:
Originally Posted by Doug Kerr View Post
Hi, Asher,

I'm not able to visualize what operation is being spoken of here. Perhaps it was discussed earlier in the thread and I was just to lazy to find it.

Could you elucidate or give a reference to where this is described?
Doug,

Look at the thin array of 6000 sensels x 3





Within the image sensor, three rows of light-sensitive photodiodes are each covered by a red, green,
or blue color filter, making the entire row sensitive to one primary color. The magnified view of the
Kodak trilinear sensor (right) shows the red, green and blue filtered sensors and part of the charge
transport assembly that carries the electrical signals from the photodiodes to the output amplifiers.


When the camera rotates on a pano head motor the linear array carrying the 3 lines of sensors doesn't progress to scan the film plane, (as happens normally), but is fixed in the center. Progression through the scene is achieved by the whole camera rotating instead! Assuming that the center of a lens is better corrected than the periphery, then we're using just the very best central strip of the image circle under these circumstances! Read more here.

Asher
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  #62  
Old December 20th, 2011, 01:02 AM
Cem_Usakligil Cem_Usakligil is offline
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Quote:
Originally Posted by Asher Kelman View Post
Doug,

Look at the thin array of 6000 sensels x 3





Within the image sensor, three rows of light-sensitive photodiodes are each covered by a red, green,
or blue color filter, making the entire row sensitive to one primary color. The magnified view of the
Kodak trilinear sensor (right) shows the red, green and blue filtered sensors and part of the charge
transport assembly that carries the electrical signals from the photodiodes to the output amplifiers.


When the camera rotates on a pano head motor and the scanning back does not scan but is fixed in the center. Assuming that the center of a lens is better corrected than the periphery, then using just a central part of the image circle and a smaller f stop, a fine thin central vertical strip is all that's ever used under these circumstances. Read more here.

Asher
Asher if I understood correctly what you are describing, it would mean that there must be a motorized pano head capable of rotating in microsteps (tens of thousands panning steps for a given fov) without causing overshoots, trilling and misalignments due to the momentum of the camera mounted atop. Next, the rotation would have be around the non parallax point of the lens. Also, the pano motor electronics would have to signal the scanning back after every rotation that a line is ready to be captured. Can you please show us a link to an actual setup of this?
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  #63  
Old December 20th, 2011, 01:36 AM
Asher Kelman Asher Kelman is offline
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Cem,

You ask the important questions.




The Pano/WideView™ Adapter when used with the Better
Light 4"x5"scanning back can create panoramic, rollout and
QTVR images. This system can capture seamless 360 degree
digital panoramic scans and wide-view images of adjustable
aspect ratio, with wide or long lenses, up to 8,000 x 65,000
pixels - the largest digital panoramic images currently possible.

Here's the answer! :)
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  #64  
Old December 20th, 2011, 05:30 AM
Grant Kernan Grant Kernan is offline
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Yes!!! The stepping motor is controlled by a chip in the Betterlight Scanning insert. The Betterlight is a high resolution (miniature flat bed scanner) built into a 4X5 (film or digital pixel holder) and built backwards. Instead of a lens and light source located inside the flatbed, it uses a camera lens to focus light at the film plane from outside of the hardware. The Betterlight Kodak Trilinear sensor either travels along that film plane or it is locked in the middle of the image circle awaiting instructions from the controller and Viewfinder software. Incidentally this is a completely tethered activity.
In Pano Mode a motor turns the camera lens and scanning back in a controllable software environment named Viewfinder. Focal length and rotation amount is entered into the software and it takes care of business. Inside Viewfinder ISO, Line time (similar to shutter speeds but in lines), tone curves, colour profiles, cropping and focus verification is all set and controlled.
The genius Mike Collette, invented designed and built the Betterlight scanning units. A -stream- of pure digital data seamlessly spills into the control box as the scan progresses to completion.

This is beyond me. I only make pictures and build my camera rigs.

BTW there are only 83-85 Betterlight pano adapters in the world, and 1500 Betterlight Scanning Inserts.

There are a few - a hand-full - so maybe 5 Super6K HS USB2 units left and perhaps 20 or less Super 8K units for sale. When they are gone they are gone, and then you will need to search EBay. All the panoadapters have been sold and 1 more batch will most likely be built in the new year. At least 10 commitments need to be made for the batch to proceed.
No promises though!

So get yours now! I know I love my Super 6K!

Grant
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  #65  
Old December 24th, 2011, 07:49 AM
CD Holden CD Holden is offline
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Quote:
Originally Posted by Asher Kelman View Post
I have sent one body with no lens to SK Grimes to evaluate for any replacement or inserting a cone for a 90mm lens.
Asher,
Which 90mm lens do you have? If it's a Super Angulon, SKG may have another order.
Grant was kind enough to put me in touch with someone wanting to get rid of a camera body, so I may find myself with one after all. I have a 90/8 SA clone (Ilex Acugon) that could work well.
Optimally, I'd like to see a bayonet system with various cones to switch between a 90 and a 65, maybe even a 115 or 135. On second thought, switching lenses will probably involve unscrewing the rear lens to get it mounted. A viewfinder would be convenient, but I'll be focusing on the GG anyway, so it may be pointless anyway. How solid of a connection is that Bronica L mount? Is there any play in it or are you confident that it's a good solid connection? I don't even own one yet and I'm already thinking of additions to the body...
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  #66  
Old December 24th, 2011, 11:27 AM
Asher Kelman Asher Kelman is offline
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Quote:
Originally Posted by CD Holden View Post
Asher,
Which 90mm lens do you have? If it's a Super Angulon, SKG may have another order.
CD,

I have no 90 mm lens at present! I just wanted Adam at S.K. Grimes to have a Globus body to work out possibilities. That's just my approach. That way he can give a reasoned comment to anyone else who seeks mods for that camera.

Quote:
Originally Posted by CD Holden View Post
How solid of a connection is that Bronica L mount?
Grant has the Bronica Mod. That steel is not very thick, LOL. However he managed to open it a tad and insert an extension tube which accepts the Bronica lenses. The focused image does not cover the 4x5 plane, but that's fine for a scanning back. I'm sure it's solid enough for a careful photographer. However, it's not to be dropped on concrete from 10 feet up!

Asher
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  #67  
Old December 24th, 2011, 01:09 PM
Asher Kelman Asher Kelman is offline
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Default Clarification: Our Globus 4x5 cameras not required for use of the Betterlight back!

Just in case folk glean from this that somehow the Globuscope is needed to use the Betterlight scanning back, let me assure you that that is not so! The Betterlight is used on any LF with a 4x5 Graflok/universal back. Just insert like a humble 4x5 film holder.

Jim Collum, for example, has been a long time creative user of the original Betterlight scanning back. In those early days the SCSSI box was heavy! His work took off even more when he acquired the majorly slimmed-down USB update! :) His pictures of incoming waves at the beach are especially interesting as when the direction of the 6000 x3 vertical RBG pixels moves left to right across the image plane to meet the oncoming waves, peaks form! Quite remarkable. In any case, visiting the Betterlight website will lead you to the work of many other talented Betterlight artists.

Grant's use of the Globuscope is just a fiendishly clever, lightweight, high resolution & contrast approach to taking advantage of an amazing imaging invention and some of the best, (and unheralded), range of bayonet MF lenses ever offered.

Asher
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  #68  
Old December 26th, 2011, 05:38 PM
Grant Kernan Grant Kernan is offline
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I have watched the details and information surrounding the Globus project camera bodies get skewed over and over again. So lets put some of it straight.

Quote:
How solid of a connection is that Bronica L mount? Is there any play in it or are you confident that it's a good solid connection? I don't even own one yet and I'm already thinking of additions to the body...

First; There is no Bronica L Mount...

Second; The reaming out of the throat is to accommodate a helical mount for a LF lens. Neither of the 645 mounts need this.

Third; The Stainless Steel has been stamped and folded around a form. This engineering process makes it light and strong similar to a cars' unibody. It would take some doing to twist the camera out of square. If it were dropped 10 feet to concrete you can bet your glass that dents to the Stainless would be the least of your worries.
The L bracket is almost 3/4 inch aluminum which I plan to lighten with holes like Swiss cheese. It will be solid as it is bolted to the Globuscope 4X5 via a 1/4 inch tripod mount and in practice it should be double side taped or siliconed to the long side of the body as well. This bracket adds to the rigidity.

Please Note: The smaller image circle of the 645 lenses are perfect for use with the Betterlight Pano adapter. And now I am adapting a 50mm f:4 Mamyia Shift lens...

The Bronica ETRS Mount and now the Mamyia 645 mount - are as solid as any lens to lens board connection as long as they are made with good materials and common sense.

For Mamyia;
I start by harvesting parts from a Mamyia Auto Extension tube #1. It is easily dismantled using good precision screw drivers and enough downward force as not to strip out the Phillips screw heads.
Then a GOOD Brass Heliopan stepping ring will make the connection as good as any screw mount lens. I choose a Heliopan step ring because it is machined from brass and it has more threads than cheaper aluminum stepping rings.
A 58 to 67mm step up ring order # 162 from B&H will slip into the 59.5 mm opening in the Globuscope.
A 62 to 58 mm step down ring will act as a locking nut on the inside of the camera and it will secure the Heliopan stepping ring . This can be made from cheaper aluminum as long as the main piece is brass. Dissimilar metals are not a bad idea.

The disassembled Mamyia bayonet mount slips easily into the 67mm opening of the 58 - 67 stepping ring. Three countersunk properly spaced and sized holes in the Heliopan stepping ring allow the two main parts to be connected...( You will need to do this), the screws and threads are already in the #1 tube. For extra security, the rig can be cemented together with epoxy or gorilla adhesive. Silicone or Sicioflex atre also good choices...once infinity focus has been established...

Stay tuned for detailed pictures and details.

Grant
Great picture-taking...
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Last edited by Grant Kernan; December 26th, 2011 at 07:30 PM. Reason: adding
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  #69  
Old December 26th, 2011, 09:37 PM
Doug Kerr Doug Kerr is offline
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Hi, Asher,

Thanks for the good scoop.

Sorry I didn't acknowledge it sooner - I got distracted and didn't pick it up.

Best regards,

Doug
Quote:
Originally Posted by Asher Kelman View Post
Doug,

Look at the thin array of 6000 sensels x 3





Within the image sensor, three rows of light-sensitive photodiodes are each covered by a red, green,
or blue color filter, making the entire row sensitive to one primary color. The magnified view of the
Kodak trilinear sensor (right) shows the red, green and blue filtered sensors and part of the charge
transport assembly that carries the electrical signals from the photodiodes to the output amplifiers.


When the camera rotates on a pano head motor the linear array carrying the 3 lines of sensors doesn't progress to scan the film plane, (as happens normally), but is fixed in the center. Progression through the scene is achieved by the whole camera rotating instead! Assuming that the center of a lens is better corrected than the periphery, then we're using just the very best central strip of the image circle under these circumstances! Read more here.

Asher
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  #70  
Old December 27th, 2011, 07:51 AM
Doug Kerr Doug Kerr is offline
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Hi, Asher,

Quote:
Originally Posted by Asher Kelman View Post
Assuming that the center of a lens is better corrected than the periphery, then we're using just the very best central strip of the image circle under these circumstances!
But the "strip" of the image circle that is used is not all at the center of the image circle; its extremities are out toward (perhaps even at) the periphery.

So, with respect to the overall panoramic image, the horizontal "stripe" lying midway between top to bottom (the "equator") is wholly a creature of the center of the image circle, but the horizontal stripe at the very top of the image is wholly a creature of a place on the image circle that is away from the center by half the length of the line sensor (presumably near the periphery of the image circle), and similarly for the horizontal stripe at the bottom of the image.

Now indeed that is presumably better than the usual situation, where only one place in the image (at its center) is a creature of the center of the image circle. But your description doesn't exactly fit the whole story.

***********

While I am here let me review the matter of the optimum pivot point for four kinds of panoramic photography.

• For multi-shot panoramic photography with a "conventional" camera, the optimum pivot point for the entire camera is the "no parallax point", which is at the entrance pupil of the lens.
Avoidance of parallax shift is the sole criterion here.
• For parallax photography with a swinging lens with a swinging slit attached to its rear, working on a fixed arc of film (e.g., a Widelux camera), the optimum pivot point for the lens assembly is at the second nodal point of the lens.
This is needed to avoid "smearing" from shift of the image from the slit as the slit traverses any region of the film. This is a more powerful criterion in most cases than the avoidance of parallax shift (which would require pivot about the entrance pupil). Lenses used in such cameras are often designed so that the entrance pupil and second nodal point are not too different in location, thus minimizing the amount of compromise.

The theory here is identical to that of the test used to determine the location of the second nodal point (such as is done elegantly with the Kingslake "T-slide" apparatus).
I believe that awareness of that test, which is inaccurately thought equivalent to the maneuver in multi-shot panoramic photography, is in part responsible for the widely-held misconception that the no parallax point is at "the" nodal point of the lens.
• For panoramic photography with a swinging camera, a slit at the focal plane, and moving film (e.g., a Cirkut camera), the optimum pivot point for the entire camera is the "no parallax point", which is at the entrance pupil of the lens.
Avoidance of parallax shift is the sole criterion here.
• For panoramic photography with a swinging camera and a fixed line sensor at the focal plane (as discussed in this thread), the optimum pivot point for the entire camera is the "no parallax point", which is at the entrance pupil of the lens.
Avoidance of parallax shift is the sole criterion here.

Best regards,

Doug
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  #71  
Old December 27th, 2011, 06:21 PM
CD Holden CD Holden is offline
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Quote:
Originally Posted by Grant Kernan View Post
<snip>
I modified the mounting block to take a Sinar Zoom Back
<snip>
Grant,
What was required to make this back work in the Globuscope body? I've shot 6x7 with my Calumet rollfilm holder in the Sinar. I've always wanted one of the Sinar backs to do 6x12. Even better if it's in a lighter camera...

Chris
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  #72  
Old December 27th, 2011, 08:08 PM
Grant Kernan Grant Kernan is offline
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A thin strip needs to be machined out of the mounting block on the Globuscope. The hinge gets in the way of inserting the Sinar Zoom Roll Back fully. PLEASE Email me and I will send you a pic...
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  #73  
Old December 31st, 2011, 02:29 AM
CD Holden CD Holden is offline
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If anyone has one of these 4x5 bodies they might be willing to get rid of, please contact me: cdholden at gmail dot com.
I'm looking for another to mount my 90mm lens on.

Thanks,
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  #74  
Old January 16th, 2012, 02:01 AM
Ben Rubinstein Ben Rubinstein is offline
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Cummon Asher, stop pretending to be jetlagged, we're dying to see what you did with the camera!
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  #75  
Old January 16th, 2012, 07:05 AM
Asher Kelman Asher Kelman is offline
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Ben,

I have to process the pictures! A few days more!

Asher
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  #76  
Old March 21st, 2012, 09:41 PM
Grant Kernan Grant Kernan is offline
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Default Images?

Asher,
Did you lose the film?
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  #77  
Old March 22nd, 2012, 01:07 AM
Asher Kelman Asher Kelman is offline
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Quote:
Originally Posted by Grant Kernan View Post
Asher,
Did you lose the film?
Grant,

I have pictures. I just need to scan them and see how the negatives came out. B&W here and color in Europe. I suspect I need a new ground "glass" as mine is concave. Am busy with shoots every day and this weekend will have a break to scan.

Asher
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  #78  
Old April 12th, 2012, 04:58 AM
Ben Rubinstein Ben Rubinstein is offline
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20 days later, cummon Asher! :-)
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  #79  
Old April 12th, 2012, 01:04 PM
Asher Kelman Asher Kelman is offline
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Quote:
Originally Posted by Ben Rubinstein View Post
20 days later, cummon Asher! :-)
Ben,

Sadly, the plastic ground glass is curved and needs to be replaced. Meanwhile I'll try to find something in focus.

Asher
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  #80  
Old June 12th, 2012, 02:03 PM
Asher Kelman Asher Kelman is offline
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Is there any downside to changing the back to the universal graphic mount? I'm getting a Maxwell Screen so I could change the mount at the same time. Also, what difference would that make to the type of roll film holders one could slip in?

Asher
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  #81  
Old June 12th, 2012, 05:41 PM
Asher Kelman Asher Kelman is offline
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Grant,

Now that you have the Bronica and Mamiya systems worked out, which would be best for both the Betterlight and also using film inserts such as the Sinar Zoom Roll Back fully. Also there any advantage to having a standard Universal/ Graflex back fitted, since some machining is needed anyway for the Sinar holder?

Asher
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Last edited by Asher Kelman; June 17th, 2012 at 11:04 PM.
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  #82  
Old June 15th, 2012, 05:44 PM
Grant Kernan Grant Kernan is offline
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The Mamiya and the Bronica lenses work with the Pano Adapter and Betterlight Scan Back because we only need to worry about coverage for the short side of the Betterlighyt format- (72 x 96 mm). This is because the (SLIT SHUTTER) is locked in the centre of lens coverage as the motor turns the whole camera.

Please: Note that the Mamiya lens choice should be an older manual type so that you can set f stops;
The Bronica ETRSI lenses all need to have their depth of field preview locked down to select a chosen f stop....use an elastic band...

A Sinar Zoom Back would need to be set at 645 format for film coverage. You would be better off using an ETRSI or Mamyia 645 camera body with film than trying to use either 645 lens with film and a roll back on - ANY- 4X5 system. These alternative lens options really only shine using the pano adapter and the Betterlight...

No advantage to standard Graphlock back!!!!
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  #83  
Old August 3rd, 2012, 03:44 PM
Asher Kelman Asher Kelman is offline
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I decided to upgrade from the rather rough pus-pull focus of the supplied 65mm Glbuscope lens. I want to be able to frame using my Fotoman eye piece and then have a helical focus that's calibrated and shimmed for this camera. That way, I do not have to use the focusing screen and this would be great for use with either 6x12, 6x9, 6x7 or 6x6 rollfilm back that I have or 4x5 film holders.

Of course, I'll also have a Maxwell Screen to check the settings, but hope to have the choice of just shooting helical focus. So I ordered the focus for B&H and waited....... weeks then several months......

Finally my 65mm Schneider Helical mount arrived in a sealed box from B&H, but without any instructions. It's very well machined and the rotation of the focus is smooth like a classic Zeiss lens with just enough resistance. Rotation is through 270 degrees plus perhaps 5 degrees more at either end. Markings are in meters and ft with DOF indicated according to F stop. There's a removable lens mounting ring with 3 notches in the front and then, provided loose, a smaller 3-notched ring with a gasket. This adapter is for the lens that comes with my globuscope. The unusual lens is in a Copal 0 shutter and separated from a fixed rear leans locked in the camera body. A push pull sticky sliding mechanism is used for focus. I'll post pictures shortly of the helical adapter.!

So here are the pictures of the Schneider helical focus for its 65mm lens.








I hope this will be helpful enough for others. I've included a cm ruler to give you a reference.

Asher
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  #84  
Old December 9th, 2012, 10:56 AM
scott bye scott bye is offline
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Hi Asher,

Did you ever get the helical to work?
What type of viewfinder did you use for your Globuscope? I tried the Mamiya 7, 43 finder; but it was too stiff for the flash slot.
I ordered some of the flock material and it was the stuff w/o the sticky back, worked out good, so I decided to order the version with the sticky back to make it an easier install. Hope it works out.

Scott
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  #85  
Old December 9th, 2012, 01:40 PM
Asher Kelman Asher Kelman is offline
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Scott,

I'll update shortly. The camera is back and ready to go!

Asher
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  #86  
Old December 9th, 2012, 05:16 PM
Bart_van_der_Wolf Bart_van_der_Wolf is offline
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Quote:
Originally Posted by scott bye View Post
I ordered some of the flock material and it was the stuff w/o the sticky back, worked out good, so I decided to order the version with the sticky back to make it an easier install. Hope it works out.
Hi Scott,

Just for the readers that didn't follow every post, which flocking material would that be? Do you have any 'before / after' comparisons to share? That information might help others looking into the situation a lot.

A sticky backing also introduces a (theoretical?) risk of out-gassing to the optical surfaces, although it also depends on the flocking carrier material (substrate). An inert substrate will prevent liberal exchange of gasses, although the exchange will probably be too low to present an issue, in a reasonable lifetime, anyway.

Cheers,
Bart
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  #87  
Old December 12th, 2012, 02:48 PM
scott bye scott bye is offline
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I screwed up and ordered the flocking material w/o the sticky backing first and it was too stiff to mold in the camera.
I then ordered the sticky back and it worked out a lot better. This was a thinner product. The only problem was trying to line up the cutout that I made to fit properly in the camera. The sticky back, really is sticky so you should do a dry fit and figure out how you are going to place the backing the camera. I had to push the material with the end of a ball point pen to tuck it in the lens area, if you know what I mean. Make sure you also press the material in the corners, especially when you are making the template. The stiffer the material the harder it is to mold to the camera.
I am not going to worry about the gassing of the sticky flocking material. I think you might have a problem gassing from desert heat, but I probably won't be in that situation.
Hopefully this solves the long exposure problem. It may even produce a better contrast. Will test it out soon. It definitely doesn't reflect light as much as the metal.

I did make a template from trial and error, using the first flocking material I bought and then tried some hard matte printing paper.

Here is a pic of the inside of the camera.



Here is the other material.



The flock material was from ProtoStar and the Self Adhesive material number is FPS01 (28" x20")
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  #88  
Old December 12th, 2012, 04:42 PM
Asher Kelman Asher Kelman is offline
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Scott,

Thanks so much for sharing! Waiting for your test to order my own material. Did you remove the lens do inset the material all the way?

Asher
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Old December 12th, 2012, 07:49 PM
scott bye scott bye is offline
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No, I decided to keep the lens on. It probably would be easier if you did remove the lens.
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Old December 30th, 2012, 01:29 PM
Grant Kernan Grant Kernan is offline
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Scott,

Is this the flocking material?

http://www.scopestuff.com/ss_flok.htm

It sounds like flocking will solve your problem. It should. I avoided that particular problem as I am using a slightly cropped image size so my 645 format lenses throws a smaller circle of light which does not bounce around as much inside the nosecone.

It all depends on what you photograph and how you use your camera.
I suspect that I will need the flocking material for use with the Mamiya 55mm Shift lens as it will most certainly bounce light around inside the chamber.

While I am at it I might as well outfit both bodies.



I have seen a number of gridded fresnel focusing lenses for sale on both Ebay and LF forum. I suspect that you have solved your focusing problem by now.

Since I now use Focus Verification in Betterlight's Viewfinder software, I rarely need to use a lupe.
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