Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Notices

Go Back   Film and Darkroom User > Equipment > Equipment miscellaneous

  ***   Click here for the FADU 2015/2014 Yearbooks   ***

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 24th December 2019, 05:55 PM
John King John King is offline
Friend
 
Join Date: Nov 2012
Location: County Durham
Posts: 3,318
Default Raising the column

I am going to start using my 2nd enlarger which is an Opemus Standard. for B&W as I have found it is markedly better than the LPL 7700. It has a condenser instead of a diffusion light box which gives better contrast and shorter exposure times. Also the negative carrier is fitted with a single anti Newton ring glass in the upper half.

The problem is it will only enlarge up to just over 10x12 with the standard column length and a 50mm lens. I can make a wall bracket to raise the height so that I can get to a little bit more enlargement greater than 12x16. Is there a formula that I can use to calculate how high the base of the will have be.
Reply With Quote
  #2  
Old 24th December 2019, 06:05 PM
Richard Gould Richard Gould is offline
Friend
 
Join Date: Dec 2008
Location: Jersey Channel Islands
Posts: 5,433
Default

I can't help with a formula for the height, but when I got mt Opemus 6, must have been 20 years ago, I got the standard model, and like you found the coloum height limiting, but in a junk shop I found a damaged and non working Opemus (Can't remember which model, but it was older than the 6), the focus controls were siezed up, and it was for sale for £1, but it had the de luxe colum, which was the same height as the de luxe model, so I changed over the coloms, they were the same fitting, and so had the extra height I wanted, still using the same enlarger to this day and the prints from the condenser head are stunning
Richard
Reply With Quote
  #3  
Old 24th December 2019, 08:05 PM
Tony Marlow Tony Marlow is offline
Friend
 
Join Date: Sep 2008
Posts: 1,282
Default

Another way to get larger prints is to get a wide angle enlarger lens, saves a bit of stretching too when focusing.
Tony
Reply With Quote
  #4  
Old 24th December 2019, 09:08 PM
John King John King is offline
Friend
 
Join Date: Nov 2012
Location: County Durham
Posts: 3,318
Default Enlarger column

Quote:
Originally Posted by Tony Marlow View Post
Another way to get larger prints is to get a wide angle enlarger lens, saves a bit of stretching too when focusing.
Tony
I am loath to change my APO Rodagon for an inferior optic, so I will pass on that. Wide angle enlarger lenses cost the same as the GNP as a small 3rd word country. I don't have to stretch either, I have the flexible focussing lead, which I wish my LPL had, it makes focussing a doddle.

I have not used the Meopta for a while and was surprised that the lamphouse does not get very hot - not as much as the LPL. So I dispensed with the upper Newton ring lass in the negative holder and focussed on the baseboard and left it for 10 mins with the lamp switched on and the focus was still absolutely perfect.

Last edited by John King; 24th December 2019 at 09:12 PM.
Reply With Quote
  #5  
Old 24th December 2019, 10:31 PM
Bob's Avatar
Bob Bob is offline
Administrator
 
Join Date: Aug 2008
Location: London(ish)
Posts: 2,746
Default

Just tried it on my enlarger: 50mm lens and a 35mm negative mask in the carrier.

16" wide at the easel, height from easel to negative = 26"
20" wide at the easel, height from easel to negative = 31.5"



The formula is H = fl * (2 + 1/M + M ) where H is the distance from the print to the negative, fl is the focal length of the lens and M is the magnification factor.

So, calculating for the 16" measured above:

35mm film (longest side = 36mm) , M for a print 16" (406.4mm) on the longest side = 406.4 / 36 = M = 11.29

From the formula:

H = 50 * (2 +1/11.29 + 11.29)

H = 668.9mm = 26.3"

which is close enuff given the usual approximations and measurement inaccuracy etc.

Last edited by Bob; 24th December 2019 at 10:53 PM.
Reply With Quote
  #6  
Old 24th December 2019, 11:45 PM
John King John King is offline
Friend
 
Join Date: Nov 2012
Location: County Durham
Posts: 3,318
Default

Thanks Bob.

I have measured the height of the column and I will have to raise it by 7" to enable me to get a 16x12 print with a 1" margin on the long side. This also includes the fact I will be dispensing with the baseboard and focussing onto the masking frame on the table.
Reply With Quote
  #7  
Old 25th December 2019, 09:41 AM
mpirie mpirie is offline
Friend
 
Join Date: Jul 2009
Location: Highlands of Scotland
Posts: 430
Default

Can you turn the head on it's side to project horizontally for bigger enlargements?

Mike
Reply With Quote
  #8  
Old 25th December 2019, 12:13 PM
Bill's Avatar
Bill Bill is offline
Moderator & Keeper of the Calendar
 
Join Date: Sep 2008
Location: Barrow - in - Furness
Posts: 1,803
Default

Quote:
Originally Posted by John King View Post
I am loath to change my APO Rodagon for an inferior optic, so I will pass on that.
Are they really inferior? I have an APO Componon 45mm f4 and a Componon S 50mm f2.8 and to be honest I cannot see any difference at the sizes I print (up to 12 x 16) except that the APO being an f4 is much harder to focus and the exposure times are longer after stopping down 3 - 4 clicks as normal.

Perhaps if you do colour, which I don’t, there may be a difference with colour fringing but for what I do, monochrome, there is no difference.

Bill
Reply With Quote
  #9  
Old 25th December 2019, 12:19 PM
John King John King is offline
Friend
 
Join Date: Nov 2012
Location: County Durham
Posts: 3,318
Default Enlarger column

Quote:
Originally Posted by mpirie View Post
Can you turn the head on it's side to project horizontally for bigger enlargements?

Mike
It isn't practical. Have you ever tried it? How do you fix the paper to the vertical surface so it stays in place. Apart from that, my darkroom is 2.2 meters wide and 4.9 meters long and moving items about, I feel is awkward, so just to get a bigger image this is not really the way to go.

No, what I am going to do is to fix a raised section onto the baseboard made up from 5 or 6 pieces of 3/4" marine ply about 5x4 inches in area glued together and screw this to the base board from underneath, then bolt the base plate directly onto this. That will give me the height I need to go up to make a print about 14" wide x 21 long more than enough for what I need.

The wall mounting idea isn't a good one either because the enlarger has a sloping column, will not allow me to stabilise the column at the top. It needs stabilising because of the weight of the head will almost certainly make it unsteady. The way I propose to do it now will not have that problem.
Reply With Quote
  #10  
Old 25th December 2019, 01:45 PM
mpirie mpirie is offline
Friend
 
Join Date: Jul 2009
Location: Highlands of Scotland
Posts: 430
Default

Horizontal projection was practical enough for St Ansel and even Clyde Butcher.

I have tried it, and it worked fine for me too. I used small magnets to hold the paper flat onto a metal masking frame.

However, another option is to turn the column 180deg around and project onto the floor, making sure to counterbalance the baseboard.

Mike
Reply With Quote
Reply
Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Leitz Focomat V35 column "collar" query M Stewart Darkroom 7 10th December 2016 12:28 AM
On the scrounge: lid and column for jobo 2500 drum DaveP Sale or Wanted 8 4th December 2011 08:09 AM
Durst enlarger centre column problem les dix Darkroom 17 10th March 2011 01:52 PM
De Vere 203: Coupling the focusing wheels to the enlarger column Tom Kershaw Darkroom 6 27th November 2010 09:23 AM


All times are GMT. The time now is 05:48 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.