massive reduction with enlarger

rbrigham · Nov 28, 2018

hi All

i need to reduce some 10x8 and 5x4 negatives
down to around 10x8mm !
i will use a rental darkroom that has a 10x8 enlarger if this is possible

anybody know how i would go about this and what lens i would need
i’m thinking long lens that coves neg but that can focus close
i think the darkroom has a 360mm
but maybe i need a 600mm or longer ?

best

robin

Steve Smith · Nov 28, 2018

You need an ensmaller!

Steve.

Canuck · Nov 28, 2018

Just an idea but how about a small LED light source, a digital camera and then post processing the files to the size you need?

removed account4 · Nov 28, 2018

hi robin
what you need is a longer bellows for the enlarger .. you can use whatever
lens you currently have on your enlarger .. think of it like doing "macro" work
with a camera but in reverse. you will also need to put your easel or whatever you are
using to print on higher up ...

have fun!

rbrigham · Nov 28, 2018

thanks Juanian

just what I need to know

best

robin

Ian C · Nov 28, 2018

The image rectangle of an 8” x 10” negative is about 195mm x 245mm, so the magnification to obtain a reduction whose minor image-dimension is 8 mm is

m = 8/195 = 0.041x

A short focal length lens is the most practical choice.

With a 50mm lens The calculated negative-to-image distance is k = 1321mm (ignoring the nodal distance).

The calculated distances are: The distance from the negative to the first nodal point (nearest the negative) of the lens is s = 1269mm, the distance from the second nodal point of the lens to the image is i = 52mm.

This uses the lens well outside of it’s intended magnification range. Both image quality and evenness of illumination might be unacceptable. Reversing the lens might help. Accurate focus would be difficult to obtain (no room to use a grain magnifier).

A longer lens would increase the distances. You’d get the following combination of:

f = focal length
k = distance from the negative to the image (ignoring the small increase due to nodal distance)
s = distance from the negative to the first nodal point of the lens
i = the distance from the second nodal point of the lens to the image.

f = 50mm, k = 1321mm, s = 1269mm, i = 52mm

f = 105mm, k = 2774mm, s = 2665mm, i = 109mm

f = 150mm, k = 3962mm, s = 3806mm, i = 156mm

f = 300mm, k = 7925mm, s = 7613mm, i = 312mm

A similar situation exists for reducing 4” x 5” negatives to 8mm x 10mm.

While possible, it probably isn’t practical. Specialized equipment for making significant reductions, microfilm systems for example, used to exist but were not generally owned for home use.

A “modern” solution, such as mentioned in post #3 might be more practical.

ic-racer · Nov 28, 2018

It is pretty simple, no specialized equipment, other than the appropriate enlarger and lens. Use a lens with the diagonal of the final image and when you raise the enlarger head the image gets smaller if you have it set up correctly. A description of enlarger handling with reductions here: https://www.photrio.com/forum/threads/cool-enlarger-trick.43223/page-2#post-2023810

Many darkroom books and manuals give detailed descriptions of reductions. If you don't have any rescources on hand how about his on-line source.
Page 10, "E. Reductions" http://www.jollinger.com/photo/cam-coll/manuals/enlargers/beseler/Beseler_CB-7.pdf
Also here 6.6.0 Reductions http://www.galerie-photo.com/manuels/durst-l184-operating-manual.pdf

In your case you would use a 25mm lens on a flat lensboard. Don't waste time reversing the lens. You may need to prop the easel on some books, depending on how high you can raise the baseboard on the 8x10 enlarger. Don't believe anyone that indicates it cannot be done. It can be done easily if you have an 8x10 enlarger.

Again, more explanation if you don't understand completely. It is like enlarging Minox to 8x10" then imagine the bellows going from the lens to the PAPER. That is the same physics/optics. The bellows draw on my Durst 8x10 will handle this with no problem.

John51 · Nov 28, 2018

Make contact prints and then copy them with a miniature camera?

Patrick Robert James · Nov 28, 2018

What you are trying to do is like enlarging in reverse, so look at it that way. You need a lens that will enlarge from the size you want to make, to the size you have (8x10). Your best bet would probably be a 50mm lens but you need to mount it in reverse. It will be difficult to focus though. Just an FYI.

Old-N-Feeble · Nov 28, 2018

Ian C · Nov 28, 2018

I tried an experiment with a 30mm 1:4.5 Minolta E Rokkor enlarging lens to get an idea of the working clearance we might get with such a short lens. This is similar to the 25mm lens proposed in post #7. I projected the image of a ceiling light 1660mm above my kitchen table onto a white sheet of paper.

With the image focused as best I could while hand-holding the lens (rear of the lens towards the ceiling), the measured distance from the “nose” of the lens to the image was about 16mm. This would be rather difficult to focus accurately. About the best you could do is to use strong reading glasses and focus by eye while looking at the image from the side.

darkroommike · Nov 28, 2018

I have actually made reductions (nothing this extreme) mostly locket prints. I solidified my reputation for genius when I started making them directly. The place I worked used to make copy negatives from contact prints on 35mm and then make prints. Needless to say, quality went up when I eliminated two generations of reproduction (not bragging, maybe a little, but just sayin'):

Use the shortest focal length you have on hand, I have a 25mm Voss, not a great lens but we are not asking a great deal of the lens, 8x10mm prints from 4x5 inch negatives or 8x10 inch negatives. If you have a Super Whoop-de-Doo APO Schneider or Rodagon so much the better. Never tried it but that Canon Macro 25mm might be the cat's pajamas, too.
Set your magnification first (reduction) just like you were shooting macro with a camera. In this case crank that bellows out to full extension to start.
Focus by moving the rig up and down above the paper, as a group, if you are using a Beseler you might find it easier to turn the knob on the motor rather than the motor switch when you get close. If all else fails get a laboratory jack, or improvise one, you will need to move the paper holder quite close to the lens anyway. Always used an old 8x10 paper box to elevate the easel when I did this.

ic-racer · Nov 28, 2018

Ian C said:
This would be rather difficult to focus accurately. About the best you could do is to use strong reading glasses and focus by eye while looking at the image from the side.

Yes, that could be the limiting issue here. I notice the front element my 25mm is recessed, so reversing it might give some more space to focus as the rear of the lens sticks out.

I was going through some things and found some tiny prints I made for an exhibition in graduate school many years ago. They are a little smaller than 'dollhouse' size, with tiny frame and labels. They are not sharp. They are 50% reductions from 6x6cm and my bellows draw on my enlarger at the time was too small, so I stopped down to f22. From a distance they look fine but with a magnifying glass they are not sharp.

mshchem · Nov 29, 2018

darkroommike said:
I have actually made reductions (nothing this extreme) mostly locket prints. I solidified my reputation for genius when I started making them directly. The place I worked used to make copy negatives from contact prints on 35mm and then make prints. Needless to say, quality went up when I eliminated two generations of reproduction (not bragging, maybe a little, but just sayin'):

Use the shortest focal length you have on hand, I have a 25mm Voss, not a great lens but we are not asking a great deal of the lens, 8x10mm prints from 4x5 inch negatives or 8x10 inch negatives. If you have a Super Whoop-de-Doo APO Schneider or Rodagon so much the better. Never tried it but that Canon Macro 25mm might be the cat's pajamas, too.

Set your magnification first (reduction) just like you were shooting macro with a camera. In this case crank that bellows out to full extension to start.

Focus by moving the rig up and down above the paper, as a group, if you are using a Beseler you might find it easier to turn the knob on the motor rather than the motor switch when you get close. If all else fails get a laboratory jack, or improvise one, you will need to move the paper holder quite close to the lens anyway. Always used an old 8x10 paper box to elevate the easel when I did this.

Yeah, this is pretty genius. I wouldn't have thought about using such a short lens. It makes sense when I think in reverse. The reverse of macro photography with bellows. The lens only needs adequate focal length to cover the size of the minature print. You would need to raise the paper darn close to the lens.
I don't have anything shorter than a 50mm.
I've seen the huge extension tubes for the old enlargers for making reductions. This process seems easier.

bernard_L · Nov 29, 2018

Why do you have to use an enlarger? Sounds like a contest "cook a pie using a refrigerator".
First off, the way you describe the task in your OP, the 8x10mm thing will be a positive if the 8"x10" is a negative. Let's leave that assumption untouched. If not, you need either reversal processing or a second copying step; irrespective of whether you use an enlarger or the method I propose below.

If I had to do that, I would just photograph the 8"x10" neg onto 35mm film using an SLR camera and a macro lens. Sure, some film area will be wasted on each frame, but... (a) whatever fine-grained film is best for the task should be available in 35mm (technical Pan??) (b) think of the convenience of frame advance and developing the tiny images all in one go in a standard spiral.
Need to hold the original flat and illuminate it evenly. I would tape(edges) it on a light table and position the camera above on a suitable tripod (or copy stand if available).

Face down? Pro: correct orientation of copy; much less risk of Newton rings between emulsion side and glass.
Face up? Pro: natural curvature of film will press it against the glass.

I would choose face up, make a note that the small copy needs to be flipped when viewed, and as needed, add a piece of finely frosted glass (so-called anti-glare at framing supplies) beween the light table and the negative.

Obtaining even illumination may not be trivial; need a good quality light table.

darkroommike · Nov 29, 2018

mshchem said:
Yeah, this is pretty genius. I wouldn't have thought about using such a short lens. It makes sense when I think in reverse. The reverse of macro photography with bellows. The lens only needs adequate focal length to cover the size of the minature print. You would need to raise the paper darn close to the lens.
I don't have anything shorter than a 50mm.
I've seen the huge extension tubes for the old enlargers for making reductions. This process seems easier.

If you add close up lenses to 50mm lenses you get shorter focal lengths! The Omega series of 4x5 enlargers also feature extension bellows for greater reductions. (One for the D2 and a similar bellows for the D3, I have one of each, not needed with the D5, etc.). Raising the paper close to the lens is why I suggested a lab jack (mini scissor jack) of a booster box.

darkroommike · Nov 29, 2018

bernard_L said:
Why do you have to use an enlarger? Sounds like a contest "cook a pie using a refrigerator".
First off, the way you describe the task in your OP, the 8x10mm thing will be a positive if the 8"x10" is a negative. Let's leave that assumption untouched. If not, you need either reversal processing or a second copying step; irrespective of whether you use an enlarger or the method I propose below.

If I had to do that, I would just photograph the 8"x10" neg onto 35mm film using an SLR camera and a macro lens. Sure, some film area will be wasted on each frame, but... (a) whatever fine-grained film is best for the task should be available in 35mm (technical Pan??) (b) think of the convenience of frame advance and developing the tiny images all in one go in a standard spiral.
Need to hold the original flat and illuminate it evenly. I would tape(edges) it on a light table and position the camera above on a suitable tripod (or copy stand if available).

Face down? Pro: correct orientation of copy; much less risk of Newton rings between emulsion side and glass.

Face up? Pro: natural curvature of film will press it against the glass.

I would choose face up, make a note that the small copy needs to be flipped when viewed, and as needed, add a piece of finely frosted glass (so-called anti-glare at framing supplies) beween the light table and the negative.

Obtaining even illumination may not be trivial; need a good quality light table.

Sure, your way works, too, but you are adding two or more generations of analog processing to the workflow. It's that old copy of a copy of a copy... thing.

mshchem · Nov 30, 2018

darkroommike said:
Sure, your way works, too, but you are adding two or more generations of analog processing to the workflow. It's that old copy of a copy of a copy... thing.

Exactly, you are using the final print to "take a picture" of the original back lit large negative. I use Beseler 45 but I have a 5x7 zone vi tonnes of bellows. Put a 4x5 neg in there and the shortest lens I have stack up some "NYC Phonebooks" under the easel see what I can get .
I'm on crutches right now due to foolishness on my part, has slowed me down. I'm hoping to be back to full speed before spring.

bernard_L · Nov 30, 2018

darkroommike said:
Sure, your way works, too, but you are adding two or more generations of analog processing to the workflow. It's that old copy of a copy of a copy... thing.

? ? ?
Am I missing something? Or could it be you?
In both cases we have

The original "some 10x8 and 5x4 negatives"
Some film to record the reduced version "down to around 10x8mm !"
and some optics in-between
- either an enlarger used way out of its comfort zone
- or a 35mm SLR + macro lens

Only the optical configuration changes. Where is my proposal "adding two or more generations of analog processing to the workflow"?

removed account4 · Nov 30, 2018

bernard_L said:
Sounds like a contest "cook a pie using a refrigerator".

not really, its just using the enlarger with its 2nd function -- to print small. people have been making jewel prints / reductions
with enlargers, since enlargers were invented ...

im always amazed at how simple tasks have answers that are overly complicated ...

its not like cooking a pie with a refrigerator, its like cooking a pie but having to first mill the wheat into flour using a pair of Keds Sneakers.

darkroommike · Nov 30, 2018

bernard_L said:
? ? ?
Am I missing something? Or could it be you?
In both cases we have

The original "some 10x8 and 5x4 negatives"

Some film to record the reduced version "down to around 10x8mm !"

and some optics in-between

either an enlarger used way out of its comfort zone

or a 35mm SLR + macro lens

Only the optical configuration changes. Where is my proposal "adding two or more generations of analog processing to the workflow"?

And is your end product a print, or a piece of film, a reduced positive, from which you make a reduced negative, from which you make a reduced print?

bernard_L · Dec 1, 2018

darkroommike said:
And is your end product a print, or a piece of film, a reduced positive, from which you make a reduced negative, from which you make a reduced print?

OP did not specify if the 8x10mm needs to be film or print. If indeed print is needed, put a piece of paper (35x40mm approx) inside the SLR film chamber. One print at a time. Still easier than trying to make a carefully designed lens operate on "the other side" of the 1:1 ratio, way outside its specification envelope.
Or finding a way to reverse an enlarging lens, and finding a grain focuser that can fit(??!!) between the lens and the easel.

Ian C said:
This uses the lens well outside of it’s intended magnification range. Both image quality and evenness of illumination might be unacceptable. Reversing the lens might help

Patrick Robert James said:
Your best bet would probably be a 50mm lens but you need to mount it in reverse. It will be difficult to focus though

My (decried) proposal makes focusing easy. And even a normal (SLR, 50mm) lens, operating at a reproduction ratio of 1/25 (8x10inches to 8x10mm) is well within its design parameter space.

John51 · Dec 1, 2018

bernard_L said:
put a piece of paper (35x40mm approx) inside the SLR film chamber. One print at a time.

Another addition to the list of things that I have to try.

rbrigham · Dec 1, 2018

thanks for all the different reply’s

the end product is a print for some jewellery
so just making miniature prints from big negs

putting close up lens’s onto the enlarger lens is an interesting idea i will be trying
i intend focusing onto a ground glass via a reflex mirror from below
and then using a surface gauge to place the paper at the same point

robin

darkroommike · Dec 2, 2018

bernard_L said:
OP did not specify if the 8x10mm needs to be film or print. If indeed print is needed, put a piece of paper (35x40mm approx) inside the SLR film chamber. One print at a time. Still easier than trying to make a carefully designed lens operate on "the other side" of the 1:1 ratio, way outside its specification envelope.
Or finding a way to reverse an enlarging lens, and finding a grain focuser that can fit(??!!) between the lens and the easel.

My (decried) proposal makes focusing easy. And even a normal (SLR, 50mm) lens, operating at a reproduction ratio of 1/25 (8x10inches to 8x10mm) is well within its design parameter space.

Load a chip of paper into a camera, expose, unload, process, repeat, ad infinitum. Still seems a lot more work, and how do you maintain alignment? Seems like a lot of work.

massive reduction with enlarger

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