Re: Poultry Cars

Daniel A. Mitchell

You’re missing the point. The geometrical dimensions do NOT describe the way the item LOOKS. I’ve agreed that the mesh is close to scale dimensionally, but it would not appear so on the model. Diffraction from such a fine mesh blurs the visiual appearance, making it look far more opaque than it may actually be. Some things do NOT "scale”.

As I stated: "The problem here is that a real item shrunk to 1/87 of it’s original size would NOT look “right” … the physics of light do not allow it."

Dan Mitchell

On Oct 28, 2018, at 12:03 AM, Ralph W. Brown <rbrown51@...> wrote:

The “high transparency” mesh I described in my earlier posts is 81% open or transparent.  Both the wire size and the mesh dimensions are very close to the prototype, but in HO scale.  See:
Ralph Brown
Portland, Maine
PRRT&HS No. 3966
NMRA No. L2532

From: Daniel A. Mitchell
Sent: Saturday, October 27, 2018 6:03 PM
Subject: Re: [RealSTMFC] Poultry Cars
Yes, I’ve looked at it. I also attended Kristen’s presentation. To me the suggested wire mesh seems about 30% transparent, vs. perhaps 90-plus% for the real poultry cars.I’ve also worked with similar real mesh. It sure does NOT look like the mesh as seen on the real poultry cars. This is undoubtedly due to lighting effects, as the mesh’s dimensions seem close to correct. I suspect a good part of this is due to both lighting angle and diffraction.
The problem here is that a real item shrunk to 1/87 of it’s original size would NOT look “right” … the physics of light do not allow it.
Dan Mitchell
On Oct 27, 2018, at 10:56 AM, Nelson Moyer <npmoyer@...> wrote:
Dan, have you visited the TWP, Inc. web page and looked at the sample photos of fine stainless steel mesh? The phots show a model’s hand holding a 3x3 swatch of each available mesh so that prospective buyers can see the transparency. The photos are front lighted, and the mesh specifications, including wire diameter and opening size, are given for each mesh. I believe you will find these photos instructive.
Nelson Moyer
From: [] On Behalf Of Daniel A. Mitchell
Sent: Saturday, October 27, 2018 8:50 AM
Subject: Re: [RealSTMFC] Poultry Cars
One only needs about 10% hole-to-matrix size to see through something when backlighted.
The poultry cars, however are very transparent when FRONT lighted. This requires more like 90% hole-to-matrix proportion. I’ve never seen really small mesh of any kind that comes even close to this proportion.
Thus, to my knowledge, all the really fine mesh available is far to opaque to represent the mesh on the poultry cars.
Dan Mitchell

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