Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Where to buy ronchi film gratings nowadays?

  • Please log in to reply
17 replies to this topic

#1 Pokemoncrusher1

Pokemoncrusher1

    Vostok 1

  • -----
  • topic starter
  • Posts: 126
  • Joined: 11 Dec 2020

Posted 17 May 2021 - 10:58 AM

Edmund is way too expensive, ronchiscreens is gone, willman bell is also gone, any other affordable alternatives? if not i guess im forced to buy a ronchi eyepice but id rather just diy it if I can. 



#2 Pinbout

Pinbout

    ISS

  • *****
  • Posts: 25,697
  • Joined: 22 Feb 2010

Posted 17 May 2021 - 11:00 AM

Edmund is way too expensive, ronchiscreens is gone, willman bell is also gone, any other affordable alternatives? if not i guess im forced to buy a ronchi eyepice but id rather just diy it if I can. 

dm me



#3 black_rig

black_rig

    Lift Off

  • -----
  • Posts: 22
  • Joined: 24 Jun 2016

Posted 20 May 2021 - 08:10 AM

Here is a way to get Ronchi screens for a few bucks: download the files and have them printed for a few bucks at one of the suggested online slide printers.

 

https://erellaz.com/...optic/gratings/


  • LU1AR likes this

#4 gregj888

gregj888

    Mercury-Atlas

  • -----
  • Posts: 2,653
  • Joined: 26 Mar 2006
  • Loc: Oregon

Posted 23 May 2021 - 03:02 PM

I just had a few sheet (8.5" x 11") printed at the local Office Depot.  About $1 per sheet.  100 lpi.  They work, but are not as crisp as the WB or older (Edmunds ?) I have around.  These were printed at 2400 dpi...

 

Will see if I can get some slides printed locally, that looks like the way to go, especially if they can use copy or litho film. 



#5 chantepierre

chantepierre

    Ranger 4

  • *****
  • Posts: 345
  • Joined: 27 Mar 2020
  • Loc: France

Posted 24 May 2021 - 12:36 AM

Find an imagesetter, you’ll get uninterrupted lines with clean edges.

#6 Pinbout

Pinbout

    ISS

  • *****
  • Posts: 25,697
  • Joined: 22 Feb 2010

Posted 24 May 2021 - 05:46 AM

I just had a few sheet (8.5" x 11") printed at the local Office Depot.  About $1 per sheet.  100 lpi.  They work, but are not as crisp as the WB or older (Edmunds ?) I have around.  These were printed at 2400 dpi...

 

Will see if I can get some slides printed locally, that looks like the way to go, especially if they can use copy or litho film. 

Look at it with a handheld microscope, you may change your opinion.

 

5E3CD5E7-03D3-414C-A274-CCCADF0551F1.jpeg
 

3285B463-220D-442C-9FB7-B105505A1AA6.jpeg



#7 gr5org

gr5org

    thegr5store

  • -----
  • Vendors
  • Posts: 254
  • Joined: 06 Sep 2018
  • Loc: Boston

Posted 24 May 2021 - 12:09 PM

@Pinbout - the print in your image on the previous post - do you know what the printer claimed was DPI?  Was it 2400?

 

2400dpi is 10 microns but I don't know how they count.  Because it's color with dots colored magenta, cyan, yellow, and black then possibly each color is counted and their claim may be exaggerated by 2X (square root of 4 - this is a 2 dimensional printer).

 

In the article they mentioned 8k dots across the 35mm slide which is 4 microns and the 4k printers would give you 8 microns.  Again, I'm not sure if those are 4 microns per color or 4 microns per pixel.



#8 Pinbout

Pinbout

    ISS

  • *****
  • Posts: 25,697
  • Joined: 22 Feb 2010

Posted 24 May 2021 - 03:49 PM

@Pinbout - the print in your image on the previous post - do you know what the printer claimed was DPI?  Was it 2400?

 

2400dpi is 10 microns but I don't know how they count.  Because it's color with dots colored magenta, cyan, yellow, and black then possibly each color is counted and their claim may be exaggerated by 2X (square root of 4 - this is a 2 dimensional printer).

 

In the article they mentioned 8k dots across the 35mm slide which is 4 microns and the 4k printers would give you 8 microns.  Again, I'm not sure if those are 4 microns per color or 4 microns per pixel.

To take the same printer... I used a pdf program that spits out to the dot level.

 

the difference was night and day, when printing lines made in illustrator compared to the pdf program.

 

this one is actually usable

 

F548AF2A-5503-4E87-8F2C-047EF07586D4.jpeg


Edited by Pinbout, 24 May 2021 - 03:50 PM.


#9 RocketScientist

RocketScientist

    Mariner 2

  • -----
  • Posts: 255
  • Joined: 28 Aug 2008
  • Loc: Vermont

Posted 24 May 2021 - 04:02 PM

What PDF program did you use?

#10 Steve Dodds

Steve Dodds

    Viking 1

  • *****
  • Posts: 946
  • Joined: 02 Apr 2007
  • Loc: Utah

Posted 24 May 2021 - 04:04 PM

I have this one, never tried it but it should work.

Attached Files



#11 Pinbout

Pinbout

    ISS

  • *****
  • Posts: 25,697
  • Joined: 22 Feb 2010

Posted 24 May 2021 - 04:13 PM

I have this one, never tried it but it should work.

You have to print it on an imagesetter 

 

I don’t care how nice a laser says it is... it will mess it up.

 

so that file has to be sent out for about $75, I forget what they charge, but it ain’t $10



#12 Steve Dodds

Steve Dodds

    Viking 1

  • *****
  • Posts: 946
  • Joined: 02 Apr 2007
  • Loc: Utah

Posted 24 May 2021 - 04:23 PM

I got this file from the guy at Ronchiscreens.com, he posted the file when he shut down.  He was printing it at 2400 dpi on a professional printer.



#13 Pinbout

Pinbout

    ISS

  • *****
  • Posts: 25,697
  • Joined: 22 Feb 2010

Posted 24 May 2021 - 06:03 PM

I got this file from the guy at Ronchiscreens.com, he posted the file when he shut down.  He was printing it at 2400 dpi on a professional printer.

I know where it came from. Try it. It won’t worker. Test it under a microscope. 



#14 Steve Dodds

Steve Dodds

    Viking 1

  • *****
  • Posts: 946
  • Joined: 02 Apr 2007
  • Loc: Utah

Posted 24 May 2021 - 06:22 PM

This is the file that Ronchiscreens.com was using to make their Ronchi's, and most of you have his screens.  Unless he's scamming me.



#15 Pinbout

Pinbout

    ISS

  • *****
  • Posts: 25,697
  • Joined: 22 Feb 2010

Posted 24 May 2021 - 09:05 PM

Anyone can download it off his sight. Try to print it on a laser printer and inspect it with a handheld scope like what you’d use to inspect the fine grind for pits.


Edited by Pinbout, 24 May 2021 - 09:06 PM.


#16 chantepierre

chantepierre

    Ranger 4

  • *****
  • Posts: 345
  • Joined: 27 Mar 2020
  • Loc: France

Posted 25 May 2021 - 12:21 AM

This is the file that Ronchiscreens.com was using to make their Ronchi's, and most of you have his screens. Unless he's scamming me.

The file is alright, but needs to be sent to an imagesetting company. The printing method is different and does not produce dots.

This was written on his website when it was still online. I made some with our graphic design studio laser printer, they were unusable. Then I found a company with film flashing machines and the result was great.

Edited by chantepierre, 25 May 2021 - 12:24 AM.

  • Pinbout likes this

#17 Pinbout

Pinbout

    ISS

  • *****
  • Posts: 25,697
  • Joined: 22 Feb 2010

Posted 25 May 2021 - 11:21 AM

What PDF program did you use?

sorry, I spoke incorrectly earlier,  its a post script editor... can't find it.  it gets down to where to dots land...



#18 brave_ulysses

brave_ulysses

    Apollo

  • -----
  • Posts: 1,406
  • Joined: 19 Apr 2009
  • Loc: far outside the wire

Posted 25 May 2021 - 12:20 PM

may be useful:

 

http://www.laserlab.com/photoplot.php

http://fineline-imag...Nov 19 2018.pdf




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics