Best way to deal with short printing time for RA4

Fatih Ayoglu · May 3, 2023

Dear all,

I have recently started on this journey and have reasonable success with RA4 prints, meaning prints are sharp, colors are correct (after few tries) however one issue which is bugging me, which also prohibits me to do any manipulation such as dodging and burning is extremely short print times. I have De Vere 504 MKV, twin lamp version, each lamp is 250W. If I need to print on 8x10 paper with minimal margins like 0.25" from 6x6 negative when the head is about 40cm high, my printing time is only 2.5 second and this is when the aperture is set to f16. I use Rodenstock APO 80/4 lens and obviously don't want to pass f8 as further than that is lowering the sharpness.

So what would be the ideal way to deal with this situation? I mean certainly I can close the aperture further but then why I spent that much to buy this expensive sharp lens. I can use ND filters I guess but they have usually color cast and that also lower the resolution. Any other ideas?

Many thanks,
Fatih

kjm · May 3, 2023

I have a similar problem, I get about 8 seconds at f/16 for a 6x6 negative on 8x10. I'm wondering if I should get a dimmer bulb, or put a dimmer in line with the enlarger.

koraks · May 3, 2023

Fatih Ayoglu said:
I can use ND filters

That would be my suggestion. Just filter out any color cast; I wouldn't worry about it.

pentaxuser · May 3, 2023

You can add neutral density to extend printing times by adding the C filter to the correct filtration i.e. if the correct filtration is 50 M and 45Y then dial in 30 C and add 30C to the 50M and 45Y or place a good neutral density filter with no colour cast under the lens

pentaxuser

Sirius Glass · May 3, 2023

My enlarge has a light switch for White light [bright for focusing], Bright filtered light and Dim filtered light, so I can dim the light source if needed.

Tom Taylor · May 3, 2023

kjm said:
I have a similar problem, I get about 8 seconds at f/16 for a 6x6 negative on 8x10. I'm wondering if I should get a dimmer bulb, or put a dimmer in line with the enlarger.

Stopping down to F22 will give you 16 seconds (half way between f16 &f22, 12 seconds). The Naked Photographer has a video showing stopping down 3 or 4 stops had little or no effect on the print.

Fatih Ayoglu · May 3, 2023

pentaxuser said:
You can add neutral density to extend printing times by adding the C filter to the correct filtration i.e. if the correct filtration is 50 M and 45Y then dial in 30 C and add 30C to the 50M and 45Y or place a good neutral density filter with no colour cast under the lens

pentaxuser

So do you mean by adding 30C, I can move all the filter +30, that will make 30C, 80M and 75Y?

That’s a good way to do if my math is correct

Fatih Ayoglu · May 3, 2023

Tom Taylor said:
Stopping down to F22 will give you 16 seconds (half way between f16 &f22, 12 seconds). The Naked Photographer has a video showing stopping down 3 or 4 stops had little or no effect on the print.

Big fan of him, will check that video

Fatih Ayoglu · May 3, 2023

pentaxuser said:
or place a good neutral density filter with no colour cast under the lens

pentaxuser

any recommended brand?

koraks · May 3, 2023

What difference would it make in the end even if your ND filter has a slight color cast? It won't induce any crossover. The effect of the filter will compensate away in your normal printing process anyway.

wiltw · May 3, 2023

Fatih Ayoglu said:
any recommended brand?

MANY high density 'neutral' density single filters FAIL to be truly 'neutral' and instead add a color cast in the resulting color photo!

Here is an example of a bluish color cast resulting from an inferior ND filter, borrowed for illustrative purposes from https://nisioptics.co.uk/nd-filters-without-colour-cast/

So if proper filter pack = 50 M and 45Y, your new ND pack should have in total 100M + 95Y + 50C.
Of course, since many dichroic heads cannot achieve that, simply insert filters into the light path. If you purchase Color Printing filters of EQUAL value, you get neutral density... 50C + 50Y + 50M, for example
Filters can be used above the negative or below the negative, where is primarily dependent upon use of choice of plastic vs. gelatine filters.

kjm · May 3, 2023

Tom Taylor said:
Stopping down to F22 will give you 16 seconds (half way between f16 &f22, 12 seconds). The Naked Photographer has a video showing stopping down 3 or 4 stops had little or no effect on the print.

Thank you for this. I can never really tell a difference personally but have tried to go with the recommended f/8 or f/11 just due to fear I might be doing something wrong. I am very new to both BW and RA4 printing, but especially RA4.

Tom Taylor · May 3, 2023

Fatih Ayoglu said:
Big fan of him, will check that video

https://www.youtube.com/watch?v=cpAB9_XERoU

DREW WILEY · May 3, 2023

Whether stopping down a lot more has a significant effect or not all depends on both the enlarging lens itself and the degree of magnification. Even printing at f/64 shows no detail loss if I'm making a 16X20 print from an 8X10 negative, becuase it's only 2X magnification; but it would be a real bad idea doing that same print size from a med format neg any stop smaller than f/16. Any generic answer is misleading. If you have a high quality glass neutral density filter, you could use that over the lens. But the preferable way to decrease the amount of light is to ratchet up all your colorhead settings another 30 or 60 cc's, providing a stop or two of extra density.
Some colorheads have built in scrims to truncate the light with the flip of a lever. Or you could add an internal scrim to your diffusion chamber above the diffuser if it's distant enough from the neg carrier to remain out of focus. Lots of options, really.

Mick Fagan · May 4, 2023

Fatih Ayoglu said:
So do you mean by adding 30C, I can move all the filter +30, that will make 30C, 80M and 75Y?

That’s a good way to do if my math is correct

That is correct.

What hasn't been mentioned is in most enlargers, and I know for sure with DeVere enlargers as I have the MkIV single bulb version, is that every 30cc of filtration is approximately 1 stop of neutral density.

In general you should be able to add 60 units of neutral density to make a 2 stop difference with the DeVere filtration.

What I sometimes do, whether doing colour or B&W, is to run with 30 units of neutral density and instead of changing time, or aperture, I change the neutral density part of the filtration for ½, ¼ or 1/3 stop density changes in the print. It's not perfect, but in general you will be quite close.

Ian C · May 4, 2023

Most good enlarging lenses are equipped with front threads. When I need more printing time, I screw on the appropriate ND filter. Depending on the lens size, your front threads might be M32 x 0.5 pitch, M40.5 x 0.5 pitch, M43 x 0.75 pitch, M48 x 0.75 pitch, M49 x 0.75 pitch, M52 x 0.75 pitch, and so forth.

I use Nikon SLR lenses. Many of these are equipped with M52 x 0.75 pitch thread. I already have ND 0.3 (1 stop = 2X time), ND 0.6 (2 stop – 4X time), and ND 0.9 (3 stop = 8X time) filters. I simply bought some inexpensive step-up rings with female 52 mm thread on the front to mount these filters on my enlarger lens when needed.

Also, my Hoya linear polarizers are essentially neutral density filters that hold back about 5/3 stops = 3.17 X.

Using an ND filter works well in printing (B&W and color) allowing you to use the aperture that gives the best combination of resolution and preservation of contrast inherent in the negative.

You can compensate for any color bias introduced by the ND filter by fine tuning the settings of the dichroic filters.

1kgcoffee · May 4, 2023

Use a longer focal length enlarging lens from higher up. Try a 150mm focal length you should be able to do closer to 10 seconds which standard in my RA4 prints.

MattKing · May 4, 2023

1kgcoffee said:
Use a longer focal length enlarging lens from higher up. Try a 150mm focal length you should be able to do closer to 10 seconds which standard in my RA4 prints.

This doesn't help - if your resulting image size on the print doesn't change.
The light intensity at the easel isn't a function of lens to paper distance. It is a function of negative to print magnification. If the print size doesn't change, the resulting magnification will be the same, and thus the intensity of the light reaching the paper won't change, which means the print time won't change.
There are other practical advantages of using longer lenses for smallish prints.

1kgcoffee · May 4, 2023

Hah Didnt think that one through - you are correct sir.

MattKing · May 4, 2023

1kgcoffee said:
Hah Didnt think that one through - you are correct sir.

Sir????

kjm · May 4, 2023

MattKing said:
This doesn't help - if your resulting image size on the print doesn't change.
The light intensity at the easel isn't a function of lens to paper distance. It is a function of negative to print magnification. If the print size doesn't change, the resulting magnification will be the same, and thus the intensity of the light reaching the paper won't change, which means the print time won't change.

Am I misunderstanding the Inverse Square law? The distance light travels lowers the intensity. A print made the same size with a lens that allows the enlarger lamp to be further from the paper would result in less light reaching the paper.

MattKing · May 4, 2023

kjm said:
Am I misunderstanding the Inverse Square law? The distance light travels lowers the intensity. A print made the same size with a lens that allows the enlarger lamp to be further from the paper would result in less light reaching the paper.

What you probably missed is that analysis doesn't apply to light being focused by a lens in an optical system. It applies to unfocused light - say from the sun - without the intervention of ray bending optical elements.

DREW WILEY · May 4, 2023

A longer focus length lens, at a particular f-stop setting and image magnification, produces the same exposure time as a shorter focal length lens at the same f-stop and same scale of magnification.

kjm · May 4, 2023

MattKing said:
What you probably missed is that analysis doesn't apply to light being focused by a lens in an optical system. It applies to unfocused light - say from the sun - without the intervention of ray bending optical elements.

Thank you, I was thinking backwards. The amount of light in front of the lens is lower, but not behind.

Best way to deal with short printing time for RA4

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