Cool enlarger trick...

[ic-racer]

When the enlarger is correctly focused, I can raise the head a little and re-focus and the image is smaller. As I keep raising the enlarger head, and re-focusing the image, and the sharp, projected image keeps getting smaller and smaller!!!

I have a simple diagram that shows how it works, can anyone figure it out before I post it?

 

[bsdunek]

Beats me! My image gets larger when I raise the head. Refocusing does make it a little smaller, but not as small as it was with the head lower.
Maybe somethings wrong with your enlarger - got the lens upside down?

 

[richard ide]

If you extend the bellows, the image gets smaller. If you compress the bellows the image gets larger. As a hypothetical example: if your film plane and easel are placed to give say a 200% enlargement and focused for sharpness of image; if you extend your lens towards the easel, it will come in to focus again at 50% size. Easy to do with a long bellows such as on a process camera, but a much more restricted range on an enlarger.

 

[Steve Smith]

can anyone figure it out before I post it?

Yes. You have the enlarger upside down!



Steve.

 

[richard ide]

Steve's answer is more thought provoking and I love it.

 

[ic-racer]

Yes. You have the enlarger upside down!



Steve.

Thats actually pretty close ...

Can anyone be more specific?

 

[Gatsby1923]

Projecting onto the ceiling then?

 

[Poohblah]

are you moving the easel, too? or just the enlarger head?

 

[Frank Szabo]

I haven't a clue, but I'll bet Mr. Brunner could figure it out using 5 pounds of sausage.

 

[Removed Account]

Are you switching to longer focal length lenses?

 

[Steve Smith]

Thats actually pretty close ...

Can anyone be more specific?

O.K. You're using the enlarger as a camera.


Steve.

 

[ath]

Your print is smaller than the negative.

 

[removed account4]

you have an auxillery bellows on your enlarger ... you are making reductions instead of enlargements
and you are refocusing the auxillery bellows, not the enlarger-stage.

 

[ic-racer]

Your print is smaller than the negative.

Yes!

 

[ic-racer]

 

[ic-racer]

I ran into this doing 1:1 projection prints. When distances A and B above are nearly equal, you can focus through both focal points. It is pretty cool because as you focus, the image becomes clear, then as you continue to move the lens stage, it gets blurry and then comes into clear focus again as you pass from slight enlargement to slight reduction. Once in the territory of 'slight reduction,' raising the head makes the image smaller.

 

[Poohblah]

just out of curiosity (and ignorance), why would you make 1:1 projection prints if you could simply make a contact print? no glass easel available? easier dodging and burning?

 

[richard ide]

I think my first post answered the question although possibly in different terms.

Regarding making 1:1 prints in an enlarger: I sometimes would get orders for several hunded prints from one negative. Using an enlarger was at least ten times faster than contacts with fewer artifacts to spot. With the Wild enlarger I used, it was very difficult to tell the difference in quality.

 

[ic-racer]

just out of curiosity (and ignorance), why would you make 1:1 projection prints if you could simply make a contact print? no glass easel available? easier dodging and burning?

I was actually comparing the two methods.

Since projection prints are much easier to make in my darkroom, I wanted to compare some 1:1s to to contact prints. I'm not going to comment on which looks better at this time. I know my Rodenstock 300mm lens field flatness deteriorates at 1:1, thus requiring f16, so the tests have not been 'fair.' A process lens would be better, but I don't have one.

 

[ic-racer]

I think my first post answered the question although possibly in different terms.

Yes.

 

[frotog]

I was actually comparing the two methods.

Since projection prints are much easier to make in my darkroom, I wanted to compare some 1:1s to to contact prints. I'm not going to comment on which looks better at this time. I know my Rodenstock 300mm lens field flatness deteriorates at 1:1, thus requiring f16, so the tests have not been 'fair.' A process lens would be better, but I don't have one.

Great post. Just the other day I stumbled upon the two focal pt. phenomenon when setting up for making prints at 1:1. Another aspect of 1:1 printing that I'm finding especially vexing is focusing; grain appears sharp under grain focuser, but soft in print. Any ideas?

 

[richard ide]

"Great post. Just the other day I stumbled upon the two focal pt. phenomenon when setting up for making prints at 1:1. Another aspect of 1:1 printing that I'm finding especially vexing is focusing; grain appears sharp under grain focuser, but soft in print. Any ideas?"

Possible reasons could include: chromatic aberrations, haze on lens surfaces causing flare, enlargement factor outside recommended range, uncoated lens etc. etc.

What lens are you using and is it coated?

Another possible reason might be your grain focusser being off.

 

[youngrichard]

Cool enlarger trick

Grain sharp in focusser, not on print... I think there is unjustified faith that all grain focussers are spot on. I have several grain focussers, including long and short Patersons, a Peak 111, and a Focoblitz. I focussed on the grain at high magnification with each and printed a small section from the middle of the negative. Only the Focoblitz gave sharp grain in the print. So the others are very slightly "out". You could try focussing a little above and below the point that your focusser says is sharp, to see if your grain gets any sharper in the print. Unfortunately there is no way to calibrate or adjust any grain focusser that I have seen.

 

[glbeas]

Unfortunately there is no way to calibrate or adjust any grain focusser that I have seen.

You can correct in one direction by pasting sheets of paper to the bottom of the focusser. The other way is a bit problematic, most folks wouldn't want to sand material off the bottom of thier scope to correct it.

 

[ZorkiKat]

You can correct in one direction by pasting sheets of paper to the bottom of the focusser. The other way is a bit problematic, most folks wouldn't want to sand material off the bottom of thier scope to correct it.

In some grain magnifiers, the mirror can be moved up or down with a simple set screw. The aerial image therefore is moved as well. The key is to get the mirror surface (if front-surfaced mirror is used) to enlarger lens distance exactly the same as the mirror surface to magnifier base/paper surface distance. Just like the reflex mirrors of slr cameras.