troubles enlarging 35mm photograph. help very much appreciated

kimclarkson10 · Mar 8, 2009

Dear all

I have recently set up a dark room in my house. I have a JPL colour enlarger C7700. It should be able to print 35mm and 120mm film. I am having no troubles with the 120 prints as I am using a 80mm lens (I think - it does not say on lens) but I know that it is fine on 120. However I am trying to print a 35mm picture and have changed the lens to the standerd 50mm. However the print only allows it to be around 10cm by 7cm and if I attempt to make it any larger it blurs out of focus and I am unable to make it in focas. It works with the 120 lens but the largest I can blow it up to is A4 and I want to blow it up to A2. Is this a condenser problem? If so how do I adapt it to make it work? Or is the problem with the lens? The man I bought it said this was the correct lens.

Any help from fellow traditionalists would be very much appreciated.

Thank you - Kim :thumbup:

compur · Mar 9, 2009

Changing size is done with one control and focus is done with another.

The control that raises and lowers the entire enlarger head is the one for
changing print size.

The control that moves the negative stage closer to or further away from the
light source is the focus.

kimclarkson10 · Mar 11, 2009

hello - I have tryed this - but still no joy - is it anything to do with the condensor?

thank you

ann · Mar 11, 2009

i hesitated to respond the first time around as i am not familar with that specific enlarger.

however, since you mentioned consendors, that could be an issue.
does this enlarger have a mixing chamber that needs to be changed when changing format size.
also, do you have to change the negative stage height when changing format and last perphas the 50mm lens needs a reverse board.

how about the fellow who sold you the enlarger, can he be more specific.

sorry i can't be more helpful.

ann · Mar 11, 2009

ps.

i thought i would google a bit and see if i could find a photo of this enlarger that might help

i did find this right away, which might be helpful

LPL Instruction Manuals

Dwig · Mar 11, 2009

If you can raise the enlarger's head far enough, which you should with this enlarger, but can't get the lens to focus then:

1. it is not a condensor issue. The wrong condensors and/or mis-placement of the condensors will not affect the image focus; it will only affect the eveness of the illumination, possibly leaving the corners completely dark.

2. your enlarger probably requires that short FL lenses (e.g. 50mm) be mounted on recessed lens boards so that they can be retracted close enough to the negative to allow for proper focus when the head is high on the column.

Given that the longer lens (75mm, 80mm, ... ?) focuses at any head position and the shorter 50mm lens focuses well at lower head positions and not at high positions, its most likely that you are using an inappropriate lens board for the 50mm lens. I'm not directly familiar with your model enlarger, but those of similar design that I've been in contact with all required a slightly recessed lens board for 50mm lenses.

Paul Ron · Mar 11, 2009

You are using the wrong enlarging lens. 80mm is for 645, 6x6 n 6x7. Get a 50mm enlarging lens for 35mm negs. Also chaning the lens will require an adjustment to the condensers as well. Check the manual for your enlarger n see if you either need to change the condenser or adjust it.

ann · Mar 11, 2009

they are changing the lens , it is the 50mm with the 35mm negatives that are the issue.

it seems strange that the lens didn't come with a recessed board, but there are stranger things happening these days with equipment.

Paul Ron · Mar 11, 2009

Well I'm not familiar with that enlarger but in general on most enlargers like my Besseler 23C, if you change the lens, you need to adjsut or change the condensor or you'll wind up with exactly what is happening here.

ummm.... since it is a color head, it's probably a diffuser n doesn't need adjusting so the resesed lens mount makes perfect sence.

ann · Mar 12, 2009

i went hunting around and found some photos of that enlarger and unlike the beseler's one does not move the condensor head. If is fixed.

with these types of enlargers it is not uncommon to switch out the mixing chamber.

however, a large mixing chamber should work with a 50mm lens.

since seeing the head, i am leaning along with someone else that the lens board needs to be reversed.

Hopefully, finding a manual will help the OP.

Dwig · Mar 12, 2009

Paul Ron said:
Well I'm not familiar with that enlarger but in general on most enlargers like my Besseler 23C, if you change the lens, you need to adjsut or change the condensor or you'll wind up with exactly what is happening here. ...

No, failure to adjust the condensors on a 23c will not cause focus issues. It will produce uneven illumination.

Since the enlarger in question uses a diffusion "mixing chamber", common in modern color heads, there is no condensor issue of any kind. Its strickly a matter of not being able to move the lens close enough to the negative to focus properly at the higher head positions. Either something is blocking the travel of the front standard or the wrong lens board is being used.

Early · Mar 13, 2009

ann said:
they are changing the lens , it is the 50mm with the 35mm negatives that are the issue.

it seems strange that the lens didn't come with a recessed board, but there are stranger things happening these days with equipment.

I doubt these enlargers (made by Saunders) even have a board. The lenses merely screw into the base.

kimclarkson10 · Mar 13, 2009

Thanks so much for everyones help - I was suprised and pleased that you are all helping a complete stranger... Us dinasours should stick together... Yes i still do not know the problem - I had a play with it this morning and it is doing exactly the same thing. I can not get in touch with the guy that sold it - and I have the instruction manual but it tells you very little... I am intrested in this reply from DWIG

2. your enlarger probably requires that short FL lenses (e.g. 50mm) be mounted on recessed lens boards so that they can be retracted close enough to the negative to allow for proper focus when the head is high on the column.

Given that the longer lens (75mm, 80mm, ... ?) focuses at any head position and the shorter 50mm lens focuses well at lower head positions and not at high positions, its most likely that you are using an inappropriate lens board for the 50mm lens. I'm not directly familiar with your model enlarger, but those of similar design that I've been in contact with all required a slightly recessed lens board for 50mm lenses.

But im not sure what he means - what is a slightly ressesed lens board?

Thank you so much everyone for trying to get me out of this sticky jam!

kimclarkson10 · Mar 13, 2009

Thanks so much for everyones help - I was suprised and pleased that you are all helping a complete stranger... Us dinasours should stick together... Yes i still do not know the problem - I had a play with it this morning and it is doing exactly the same thing. I can not get in touch with the guy that sold it - and I have the instruction manual but it tells you very little... I am intrested in this reply from DWIG

2. your enlarger probably requires that short FL lenses (e.g. 50mm) be mounted on recessed lens boards so that they can be retracted close enough to the negative to allow for proper focus when the head is high on the column.

Given that the longer lens (75mm, 80mm, ... ?) focuses at any head position and the shorter 50mm lens focuses well at lower head positions and not at high positions, its most likely that you are using an inappropriate lens board for the 50mm lens. I'm not directly familiar with your model enlarger, but those of similar design that I've been in contact with all required a slightly recessed lens board for 50mm lenses.

But im not sure what he means - what is a slightly ressesed lens board?

Thank you so much everyone for trying to get me out of this sticky jam!

Dwig · Mar 13, 2009

kimclarkson10 said:
...
But im not sure what he means - what is a slightly ressesed lens board?
...

Many enlargers of this type are built around an interchangable lens board, of some form, rather than simply having the mounting threads machined into the moving lens standard (the metal plate that moves and is attached to the bottom end of the bellows). This allows for handling lenses with different mounting threads, although the M39 "Leica" thread is the dominant mount in lenses 80mm and shorter. It also allows for having lens boards that are recessed (e.i the hole for the lens is in a recessed "cup" allowing the lens to be closer to the negative than it would on a flat board).

The enlargers similar to yours (Durst, Saunders, LPL, ...) that I have dealt with (~15-35 years ago when I ran camera specialty stores) used lens boards that were a disk and were held in with a retaining screw on the side or front. Some models used a reversable disk that could be mounted so that it protruded slightly, for use with 75-90mm lenses, or fliped over and mounted so that the lens mounting threads were recessed into the bellows slightly to allow 50mm lenses to focus properly. On these models, leaving the board in its protruding orientation when a 50mm lens was mounted would prevent the enlarger from focusing when attempting to make large prints (head in the middle or upper portion of the column) but could be of some use when attempting to make particularily small prints (e.g. to fit a locket, ...), though make such small prints is often better accomplished by using a longer lens like an 80mm.

Examine the front lens standard and see if there is a removable disk or square board. If its a reversable disk of the type I've seen, it will probably be a black aluminum affair with a beveled outer edge on both sides that is void of paint. There will also be a ring around the lens mounting threads that has been machined flat leaving no paint, again on both sides. If this is what your machine has, flip it over so that it sticks into the bellows when mounting the 50mm lens.