Re: FS 4x5 Ultra Fine Focusing and Calibration
So does the set up take into fact that sheet film is able to float around in the sheet film holder by as much as 0.010 on inch this depends on the age and make of the holder. It can also bow out more in the center depending on how the camera is being used. Also different makes of film are made on different thickness of stock varying about 0.003 of inch.
Re: FS 4x5 Ultra Fine Focusing and Calibration
Whew rvhalejr! Your verbosity is really scuttling my curiosity.
Nate Potter, Austin TX.
Re: FS 4x5 Ultra Fine Focusing and Calibration
I have no idea what this thread is getting at but something tells me I want it. Is this a product usable on 8x10?
Re: FS 4x5 Ultra Fine Focusing and Calibration
Quote:
Originally Posted by
RichardRitter
So does the set up take into fact that sheet film is able to float around in the sheet film holder by as much as 0.010 on inch this depends on the age and make of the holder. It can also bow out more in the center depending on how the camera is being used. Also different makes of film are made on different thickness of stock varying about 0.003 of inch.
Greetings Richard,
Let me address each of the issues you have raised, but first a make a quick comment.
The kit is designed to let 90 percent of the geared 4x5 systems focus with awesome accuracy. It does, however, require skills to be acquired and a learning curve (training would be a great aid if available). You will have much better control and understanding of each lenses' characteristics than would other wise be possible.
> So does the set up take into fact that sheet film is able to float around in the
> sheet film holder by as much as 0.010 on inch this depends on the age and
> make of the holder.
As you have indicated, getting this finely focused precision image onto film is the biggest problem right now. The higher end kits are designed to help weed out the
poor holders from the better ones. As far as .010 of an inch goes Quick Loads and Ready loads (and out of flat holders in general) are so sloppy that better focusing will have almost no effect and are not recommend unless a lot of softness is acceptable.
> It can also bow out more in the center depending on how the camera is being used.
Yes, that is a known problem with some types of photography, 8x10 and larger formats.
Yet it is possible to tape down film (using a refined version of the betterscanning.com method) to better that +/- .001" (it will have a perfect mirror reflection with no distortion). To my knowledge, there is not a holder available yet to hold this type of septum (or precision plenum). :( sigh
Right now out of the 4x5 box film curl is killing us. If you are lucky enough to get 4x5 fuji, kodak, ilford, etc. out of the box flat (ideally within +/- .0005") and place it in a good quality film holder (flat within +/- .001") one can capture an outstanding image.
> Also different makes of film are made on different thickness of stock varying about 0.003 of inch.
Absolutely. Off the top of my head I think 4x5 films vary from about .006" to .010"
these days. 120/220 backs seem to work well (that reverse curl is known to cause problems if the film sits to long though) and is generally thinner than the sheet film.
The critical dimension will vary (as the documentation discusses) from film type to
film type. That means a dedicated precision plenum will be required for each type
of film and a validating set of bracket shots (with an incrementally differing critical
dimension for each) will be required for every system otherwise we are back to
guessing.
All the best,
Richard V. Hale Jr. (hence the unique rvhalejr user name)
Re: FS 4x5 Ultra Fine Focusing and Calibration
Quote:
Originally Posted by
Nathan Potter
Whew rvhalejr! Your verbosity is really scuttling my curiosity.
Nate Potter, Austin TX.
Its an important technique used to avoid mis-understanding, which we have all
had to much of already.
Re: FS 4x5 Ultra Fine Focusing and Calibration
Quote:
Originally Posted by
Sizam
I have no idea what this thread is getting at but something tells me I want it. Is this a product usable on 8x10?
Yes, I have an 8x10 plenum in stock and 3 out of 4 the four loupe stands ready to go.
Re: Image and Document Preview Available
There are about 8 .pdf pages attached to messages above that
contain information and images that describe the product in
more detail.
Re: FS 4x5 Ultra Fine Focusing and Calibration
I have moved this to the "announcements" area as this is a product that may interest many. The "for sale" area is NOT for business to sell their wares and clearly states that. This thread should be kept to providing information about the product and related questions. Sales should be handled through the business' web site. Links to Ebay sales et all are not acceptable.
Re: Images and Documentation Preview Loupe Stands
Quote:
Originally Posted by
Kirk Gittings
I have moved this to the "announcements" area as this is a product that may interest many. The "for sale" area is NOT for business to sell their wares and clearly states that. This thread should be kept to providing information about the product and related questions. Sales should be handled through the business' web site. Links to Ebay sales et all are not acceptable.
Attached are 4 preview pages (1,2,3 and 17 with images) of the loupe stands.
Policy Noted, Thanks,
Richard
Re: Sheet Film Preview 4x5 Ultra Fine Focusing and Calibration
Quote:
Originally Posted by
Kirk Gittings
I have moved this to the "announcements" area as this is a product that may interest many. The "for sale" area is NOT for business to sell their wares and clearly states that. This thread should be kept to providing information about the product and related questions. Sales should be handled through the business' web site. Links to Ebay sales et all are not acceptable.
Attached are four Sheet film preview pages (1,2,3,4 images and documentation)
Policy Noted. Some of the challenges posed by out of the box film curl are
mentioned here.
If you are lucky enough to be using perfectly flat film in a good quality holder
then the following does not apply. However, if the film you need to obtain
a specific look (a unique brand of C41, E6 or B&W) is curled out of the box
then the following may be of interest.
The fourth page is the most significant as it contains the reflection from
the emulsion of a 4x5 film that has been taped down to +/- .0005" using
rollers similar to drum scan mounting or that documented with the flat
bed betterscanning 4x5 film holder.
This reflection was carefully inspected for any distortion and was verified to
be mirror like. This demonstrates that out of the box film curl can be tamed.
The bad news is that the septum size in the 4x5 film holders is to small to roll
and tape mount film (it was a very time consuming experience and was very
disappointing when it failed on the very last step).
An Infrared camera and or Headset have not been tested yet for use in the
black bag or dark room.
Crafting a "film holder" to expose plenum rolled and taped film is proving to be
(as expected) extremely difficult, expensive and time consuming. Hopefully a
working prototype will eventually result in something I can use reliably without
that much difficulty.
All the Best for Now,
Richard