Where it goes wrong in the darkroom? Images printed not sharp enough with new enlarger lens

Dali · Dec 4, 2023

Neg in a Durst M605 Color cannot heat up due to the head's design and the heat filter in the light path.

Most probable cause is an uncalibrated grain magnifier or a lens panel not correctly adjusted to the head (rare but it happened to me last month...).

Pieter12 · Dec 4, 2023

The OP states the image looks sharp with his focusing magnifier, I will assume that means he can see the grain clearly. So no issue with the focuser. Alignment would only affect part of the image's sharpness, usually a corner or even one side. Others have pointed out that the enlarger's light path would not transfer enough heat to buckle the negative--which I will also assume is 35mm because of the focal length of the enlarger lens--and 35 does not tend to buckle as much as 120 or 4x5, so that comes close to ruling out that conclusion. Vibration also is probably not a problem unless exposure times are excessive and the enlarger is on a wobbly table on the second floor of a building with a lot of truck traffic going by. Or a washer on spin cycle in the next (or the same) room.

Also, he says the negatives printed sharper in a different darkroom, so I would examine the difference between the two--there might be something there. Is it the same paper and the same set of filters, printing at the same grade? Is the easel similar enough not to be a factor?

Lastly, I would clean everything on the Durst enlarger--condenser lens(es), enlarging lens, any mirrors or reflectors.

DREW WILEY · Dec 4, 2023

One is always gambling if they use glassless carriers, and the odds are against you.

Dali · Dec 4, 2023

Pieter12 said:
The OP states the image looks sharp with his focusing magnifier, I will assume that means he can see the grain clearly.

OK but I does not mean it will be sharp on the paper if the magnifier is not calibrated.

MattKing · Dec 4, 2023

Was the same focusing magnifier used with the enlarger and lens that produced the "sharper" print?

Pieter12 · Dec 4, 2023

Dali said:
OK but I does not mean it will be sharp on the paper if the magnifier is not calibrated.

That means?

MattKing · Dec 4, 2023

Pieter12 said:
That means?

If the magnifier is not correct, it will indicate a position of optimum focus that would only work with the paper at a different distance from the negative than it actually is.

Melvin J Bramley · Dec 4, 2023

xkaes said:
If you lack a loupe, another option is to examine the negative using the enlarging lens as a magnifying glass. Look for something in the negative that should be in focus and has a sharp edge. Does it appear sharp in the negative?

Your 50mm f3.5 should be fine if stopped down to f8. APO glass? That's for color work.

APO glass? That's for color work.

Another myth exposed!

TB

Don_ih · Dec 4, 2023

Dali said:
OK but I does not mean it will be sharp on the paper if the magnifier is not calibrated.

If it's the regular Paterson finder (the most common one), there is no calibration other than the eyepiece. If you can see sharp grain, the negative is in focus. The distance from the base of the finder to the mirror is fixed at manufacture - it cannot change. The eyepiece adjustment is only to see the mirror clearly.

Someone mentioned a different Paterson finder above - maybe that one can be calibrated.

Pieter12 · Dec 4, 2023

Don_ih said:
If it's the regular Paterson finder (the most common one), there is no calibration other than the eyepiece. If you can see sharp grain, the negative is in focus. The distance from the base of the finder to the mirror is fixed at manufacture - it cannot change. The eyepiece adjustment is only to see the mirror clearly.

Someone mentioned a different Paterson finder above - maybe that one can be calibrated.

+1

MattKing · Dec 4, 2023

Melvin J Bramley said:
APO glass? That's for color work.

Another myth exposed!

TB

Actually no.
More critical with colour work, but still advantageous with some black and white work.
Apochromatic means that all colours of light are focused to the same distance.
Which becomes more and more important, the larger you enlarge.
The APO lenses though do exhibit some other less critical refinements. Apparently people expect all the advantages, large and small, when they spend the money that a new APO lens was priced at.

Bill Burk · Dec 5, 2023

@Lachlan Young mentioned vibration earlier.

I’ve been using a stereo zoom microscope lately to work on light meter repairs. I happen to have it mounted on a Durst M600 column. It’s a pole column vs a square column on the M605 but I think it helps illustrate the point.

I have been noticing the vibration because I have to wait for it to see what I’m working on.

Here’s what it looks like. You can avoid blur if you wait a good fifteen seconds between putting the paper in the easel and pressing the timer start.

You should isolate the timer from the enlarger. Have it on a separate table if possible. Because pushing start shouldn’t bump the enlarger.

Be sure you have s sturdy table and you don’t have environmental vibration sources.

It’s only halfway up the column and it shakes this much…

Hilo · Dec 5, 2023

Surely, the OP can no longer see the forest for all the trees

Kino · Dec 5, 2023

Hilo said:
Surely, the OP can no longer see the forest for all the trees

When you concentrate so much experience and opinion in one place, the unsuspecting neophyte gets mobbed and runs in confusion...

(BTW, not a criticism, just an observation)

Rick A · Dec 5, 2023

Bill Burk said:
@Lachlan Young mentioned vibration earlier.

I’ve been using a stereo zoom microscope lately to work on light meter repairs. I happen to have it mounted on a Durst M600 column. It’s a pole column vs a square column on the M605 but I think it helps illustrate the point.

I have been noticing the vibration because I have to wait for it to see what I’m working on.

Here’s what it looks like. You can avoid blur if you wait a good fifteen seconds between putting the paper in the easel and pressing the timer start.

You should isolate the timer from the enlarger. Have it on a separate table if possible. Because pushing start shouldn’t bump the enlarger.

Be sure you have s sturdy table and you don’t have environmental vibration sources.

It’s only halfway up the column and it shakes this much…

Years ago I had vibration blur issues and did everything I could think of to isolate it, turned out it was caused by the refrigerator on the other side of the wall from my DR.

Ian C · Dec 5, 2023

My first enlarger was an Omega B66XL with the Dichroic B color head. It has a heat-absorbing filter incorporated into the color head. If I place the sensitive back of my hand directly under the lens with the lamp on and hold it there with the aperture wide open, I cannot discern any heat. Nonetheless, it can cause a negative to warm enough to temporarily pop to cause a defocusing problem, depending on the density of the negative and how long the lamp is left on. Not all negatives produce the popping on this enlarger or at least, not as much as I experience with my Beseler 23CII with condenser unit.

The same is true of my Saunders/LPL 7700 with the 670MXL dichroic color head. I acquired glass negative carriers for both of these enlargers and the problem disappeared, even when using particularly long exposures to make large prints from relatively dense negatives. This seems to be worse with 6 x 6 cm and 6 x 7 cm negatives than with 35 mm negatives.

The negative popping problem is much worse with my Beseler 23CII and Omega DII enlargers. I can’t feel any heat using the back of my hand directly under the lens. Even so, they both pop negatives significantly after 8 - 15 seconds of lamp-on time. Both use an opal photo lamp and condensers. I’ve equipped these with heat-absorbing filters and glass carriers to cure their severe negative popping. Once I did that, the projections remain uniformly focused regardless of the exposure time.

In the discussion for which I gave the link in post #32, there is an outline for making a simple temporary glass carrier fashioned out of two small sheets of window glass. This is easily done and costs very little. Using this will instantly show whether the problem is caused by negative popping or not. I recommend trying this for a definitive answer. Assuming that you do so:

If the problem persists, then you know that negative popping is not the cause.

If the problem abruptly disappears, then it is almost certainly due to negative popping.

Lachlan Young · Dec 5, 2023

Bill Burk said:
@Lachlan Young mentioned vibration earlier.

I’ve been using a stereo zoom microscope lately to work on light meter repairs. I happen to have it mounted on a Durst M600 column. It’s a pole column vs a square column on the M605 but I think it helps illustrate the point.

I have been noticing the vibration because I have to wait for it to see what I’m working on.

Here’s what it looks like. You can avoid blur if you wait a good fifteen seconds between putting the paper in the easel and pressing the timer start.

You should isolate the timer from the enlarger. Have it on a separate table if possible. Because pushing start shouldn’t bump the enlarger.

Be sure you have s sturdy table and you don’t have environmental vibration sources.

It’s only halfway up the column and it shakes this much…

This is quite like what I found with an M670 (which does have a longer column than the M605) over a decade ago - it was not extremely unsharp, but it was visibly 'off' compared to something verifiably solid (a De Vere 504) - and the amount of difference in vibration damping needed to cause a loss of OTF/ MTF sharpness that can be seen in a side-by-side is not much, but the difference needed for it to be really visibly obvious without a comparison print is quite a lot. I think that social conditioning about supposed unsharpness/ softness of grain (it shouldn't be - especially with most normal fine-grain developers) in 35mm negs is also to blame.

At least part of the cult of the Focomat is (I suspect) due to them being much better vibration damped than many other similarly sized machines.

Carnie Bob · Dec 5, 2023

DREW WILEY said:
One is always gambling if they use glassless carriers, and the odds are against you.

Plus one, without a glass carrier you are chancing negative pop no matter what lens you use.

Roger Cole · Dec 5, 2023

Pieter12 said:
A focusing magnifier either works or it doesn’t. Simple, is the grain in focus? If not the eyepiece needs to be adjusted so the reference line or lines is sharp. I suspect your home set up is a diffusion head an my even be out of alignment compared to another leather that is properly aligned and might have a condenser head, which is inherently sharper.

A condenser head is not inherently sharper. It is inherently contrastier, which gives a look of more sharpness, but if contrast is adjusted via filtration and/or development to be equal the sharpness will be equal as well.

xkaes · Dec 5, 2023

Roger Cole said:
A condenser head is not inherently sharper. It is inherently contrastier, which gives a look of more sharpness, but if contrast is adjusted via filtration and/or development to be equal the sharpness will be equal as well.

You nailed it. I was going to say the same thing, but feared a "rabbit-hole" response. The head has nothing to do with whether the print appears sharp -- in this instance. And chances are vibration has nothing to do with this "case" as well. Responders are on a fishing expedition, listing every possible explanation -- not the likely ones. I think the OP should use an enlarger outside of a seismic-activity zone -- those Indonesian earthquakes can cause untold destruction around the world.

DREW WILEY · Dec 5, 2023

Fishing expedition? I encountered EVERY SINGLE ONE of the mentioned possibilities back when I started out long ago with lightweight MF enlargers, and had to iron them out one by one. Now all my enlargers are commercial duty LF ones built like tanks.

Yeah, this IS an earthquake zone - I'm only a few block away from an infamous SF area fault - and everything is heavily bolted to both wall and floor. But it is also a fact that a simple colorhead fan that isn't properly balanced can induce enough vibration to affect print sharpness. Another culprit was a peristaltic little vacuum pump which jiggled the surface of a vacuum easel. After that, I went strictly to rotary pumps. All kinds of issues can potentially pop up. When I've been in other people's darkrooms, I'm often amazed how poorly supported their enlarger columns are. No wonder they have trouble. Or they've set up their gear atop a flimsy plywood floor that jiggles if they put their foot down too hard.

xkaes · Dec 5, 2023

DREW WILEY said:
Fishing expedition? I encountered EVERY SINGLE ONE of the mentioned possibilities back when I started out long ago with lightweight MF enlargers, and had to iron them out one by one. Now all my enlargers are commercial duty LF ones built like tanks.

Exactly like I said in Post #36 -- "I'm surprised that no one has suggested he buy a new enlarger."

Turning molehills into mountains -- our favorite approach.

koraks · Dec 5, 2023

xkaes said:
Exactly like I said in Post #36 -- "I'm surprised that no one has suggested he buy a new enlarger."

Turning molehills into mountains -- our favorite approach.

I agree.
The M605 is a fine enlarger. Sharp prints can be made with it all day, every day.

I'm sure OP will post back with some more details and hopefully examples of the unsharpness so they can receive some more focused help.

BMbikerider · Dec 5, 2023

koraks said:
I've used one for years. Unless it's used directly on top of a very active fault or in the basement of a busy railway station, the M605 is plenty sturdy enough to not suffer from vibration issues.

100% agree. A solid floor and a solid and well secured bench or table is needed. Mine is in an upstairs room with a wooden floor, but my table is solid hardwood and weighs around 55Kilos (around about 110 pounds).

BMbikerider · Dec 5, 2023

Dali said:
Neg in a Durst M605 Color cannot heat up due to the head's design and the heat filter in the light path.

Most probable cause is an uncalibrated grain magnifier or a lens panel not correctly adjusted to the head (rare but it happened to me last month...).

Irrespective of the heat filter, long exposures will make the head heat up and affect the focus plane the neg is sitting in. A change of even .25 of a mm will destroy any sharp focus. It certainly does with my LPL7700 which is a good solid bit of kit. For big enlargements with exposures over 25s I always use glass carrier.

Where it goes wrong in the darkroom? Images printed not sharp enough with new enlarger lens

Dali

Pieter12

DREW WILEY

Dali

MattKing

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Melvin J Bramley

Don_ih

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Bill Burk

Hilo

Kino

Rick A

Ian C

Lachlan Young

Carnie Bob

Roger Cole

xkaes

DREW WILEY

xkaes

koraks

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Where it goes wrong in the darkroom? Images printed not sharp enough with new enlarger lens

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