Optimizing enlarger setup for 2-1/4x3-1/4 (6x9) negatives

[C-130 Nav]

After reviewing other posts, I appear to have a similar experience regarding very short exposure times. Rather than hijack someone else's post to get input, I created a new one.

Here's my situation: I'm getting 4-6 second exposures on 4x6 prints (my preferred print size) at f/16 or 2-3 seconds if I use f/11. I feel this is too quick and leaves me limited time to work with the print. Using f/16 or f/22 may introduce diffraction although I didn't see any on my f/16 prints.

My setup is as follows:

2-1/4 x 3-1/4 negatives (6x9) - developed specifically for condenser enlarging (about 15% time correction, result is about a grade 2 negative)
Omega D-II enlarger
PH211 75W enlarger bulb (probably halfway through its lifespan)
161mm Kodak Ektanon enlarging lens
6-1/2 inch condenser (appropriate for 161mm lens)
4-1/2 inch lens cone (appropriate for 161mm lens)
Ilford Multigrade RC glossy paper (their latest version)
Ilford Multigrade filters below the lens (usually in the 1 to 2 filter range)
Dektol developer @ normal dilution for 90 seconds

I know I'm making relatively small enlargements off a large negative (rough math says this is about about 2x enlargement) which means the enlarger might be just too bright at this setting despite the 161mm lens. I do have a 7.5 inch Kodak Ektanon enlarging lens (190mm) but the Omega D-II lacks the ability to correctly use it (rails too short, lens cones too short, condensers not optimal).

Research on this forum has suggested the following:
1) Use an ND filter to increase exposure times
2) Reduce lamp intensity through a resistor or variac
3) Use a different bulb (fairly certain there isn't a lower wattage equivalent for the PH211)
4) Use a slower paper (haven't researched this possibility)

My question: Are there any other things to consider to lengthen my exposures to the 10-15s range and bring my f-stop down to f-11 to avoid diffraction?

Thank you!
Dan

 

[NedL]

Interesting. When you posted about short times before I didn't realize you were making such small prints. I have slight trouble making a 5x7" print from a 6x9 negative with a 105mm enlarging lens ( it's right at the end of how far down the bellows on my enlarger will go ). Although I'm a little surprised it's still a problem with the 160mm lens you're using. Sorry not sure what to suggest, but I sympathize that those are short exposures... I like to aim for 20+ seconds when I can.... ND filter seems like a good bet to me.

 

[C-130 Nav]

NedL - thanks for the reply. I do have a couple ND filters that I can try and that will likely be my next go.

As means of an update from previous, I've made some adjustments to my setup for my 35mm work. While my 10-15s time is shorter than your 20+ second target, it's manageable. My setup for 35mm is the same as above except:

100mm Kodak Ektar enlarging lens
4-1/2 inch condenser (appropriate for 100mm lens)
flat lens board (appropriate for 100mm lens)

Previously I had problems with light falloff in the corners on 8x10 enlargements using a 50mm and the 4-1/2 inch condenser. That problem went away after 1) I switched to the 3 inch condenser, 2) swapped lamp heads to one that seems to be better aligned and 3) accomplished a full enlarger realignment. One or more of those things fixed my issue. As I normally print 4x6s, I use a the 100mm mostly with 35mm as that raises the enlarger head to a more reasonable geometry. I switch to the 50mm for 8x10s.

 

[Maris]

I make a lot of small prints around December time as Xmas cards and the short enlarger time problem arises. The lens I use , a Fujinon-EP 135mm f5.6, stops down to f45. The diffraction is there and I can see it through the grain magnifier but I can't see it in the enlargement because of the small print size.

There is potentially a problem with very small apertures on an enlarging lens because of the strongly increased depth of field. The lens now "sees" up through the negative and into the condenser system.
Any specks of dust on a condenser surface will be imaged as small blurry pale spots in the enlargement.

Since I use below-the-lens contrast filters I just add a ND3 gel to the filter pack and work at a much more comfortable f11.

 

[Pieter12]

Does the enlarger have a filter drawer? ND gels are dirt cheap and you can stack them without affecting image quality.

 

[C-130 Nav]

The D-II had a couple of lamp head options, two of which allowed for filters.

The earliest version had no filter provision - this is what is on my enlarger now.
The "colorhead" version used giant, odd size (over 6 inches) filters and that was on my enlarger originally. Since I didn't want to cut down larger, more expensive filters and it leaked light, I switched back to the original version without the filter option.

Omega did come out with another head that allows for 5 inch filters in a drawer - but I don't have one of those heads.

So - I currently use under the lens filters. Like Maris said above, I'll probably just stack an ND filter with my contrast filter.

 

[MTGseattle]

I've been away from the darkroom for a number of years. I keep hoping to get back in there, and I have a pile of mothballed gear begging for use.
I've seen reference to ND filters used a number of times recently, but I can't recall hearing this advice 30 years ago. Are there any downsides to using one?

Sorry to the Op for the hijack. I wish I had a useful nugget of info. You do seem to be doubling the "normal" focal lengths for you given formats.
Is this what gets you the various print sizes you prefer?
Is there any chance of the condensers themselves being installed wrong? upside-down or reversed?

The following is a quote from the KHB Photographix web site and possibly helps?

" Used Advice: This head is perfectly usable as long as it's in good condition and all parts and accessory condenser sets are included. If only the 6½" condenser set is present, a DV conversion kit can be installed to accommodate formats smaller than 4"x5".

Here's a link to the Jollinger scanned omega d2 manual. what it says about the 6-1/2" Opal glass may be pertinent. Apologies if you have been through all of this stuff already.

http://jollinger.com/photo/cam-coll/manuals/enlargers/omega/Omega_DII_%20Cat.pdf

 

[C-130 Nav]

To respond to the previous post, I effectively doubled the recommended focal length for 35mm film because I prefer smaller prints. The 50mm lens can’t give me the size I want at the bottom end of the enlarger rails. So I went with a 100mm lens combo. I don’t seye any undesirable effects on my prints.

As for the condensers, the early D-II (not a D-2) like mine came with separate condensers mounted in their own aluminum cylinders. I have one each of the 3 sizes that were made. Later versions came with a variable condenser head that had moveable/removable condenser elements. I don’t know if those can be installed upside down but they can be installed in the incorrect slots.

I’ll review the note on opal glass. I am not using any and that might help.

Thanks much.

 

[MTGseattle]

Sounds good. I was just grasping at possible straws for you. You mentioned the 6-1/2" glass, and that number stuck out for me in some brief reading.

 

[MattKing]

I think you understand this, but using the longer lens does nothing to decrease the light intensity or increase exposure times - it just gives you more room under the lens and (usually) a few more options for small apertures.
Can you put an ND filter on top of your condenser(s)? It won't be convenient to handle, but it might give you a long term solution.

 

[Philippe-Georges]

I find ND filters are the best way to go.
In my Omega D3 enlarger there is a 75W (220V) bulb, but as I like to dodge (a lot) I do prefer longish exposure times (sometimes around 100sec.) I add a ND 0.6 alternated or combined with a ND 0.3 filter, on top of a glass plate (heat) mounted above the variable condenser, and put the variable contrast filters (Ilford) on top of the fixed condensers set.

A rheostat changes the colour of the bulb which, I think, influences the contrast determining of the VC filters.

This is in combination with Hp5+/120 (in X-Tol 1+1) on FomaBrom Variant III FB paper (in a Dektol clone), and non the least, I am convinced that F8 is the best aperture of the Rodagon lenses...

 

[koraks]

1) Use an ND filter to increase exposure times
2) Reduce lamp intensity through a resistor or variac
3) Use a different bulb (fairly certain there isn't a lower wattage equivalent for the PH211)
4) Use a slower paper (haven't researched this possibility)

1: An obvious choice. Several have recommended it and I can only agree.
2: Burning heat in a resistor is impractical and silly. It's not worth considering. A variac is a feasible option, but rather expensive and somewhat bulky, although you don't need a particularly big one. But far more costly than a set of ND filters.
3: Even a 35W bulb would still only make a single stop of difference.
4: Something like Fomatone would certainly be much slower; you'll 'gain' (lose) about two stops. But it's not RC and I'm not sure if you want to deal with FB, which is beautiful, but also a little more time-consuming.

Add a 5th option: print bigger

 

[Ian C]

Apparently, you have exposures as short as 4 seconds at f/16 and would like to get them to be about 20 seconds at the lens’s optimum aperture.

The Kodak Ektanon lenses you have are f/4.5. Enlarging lenses generally produce the best combination of resolution and preservation of contrast closed about 2 stops from wide open. So, their optimum aperture is likely about f/9. On the aperture ring, that’s about 1/3rd of the distance from f/8 towards f/11. It’s simpler to choose f/11.

ND filters are made in 1-stop increments. If you open from f/16 to f/11 and use a 3-stop filter, your printing time will be 16 seconds. With a 4-stop filter, the f/11 printing time will be 32 seconds.

Here’s an example of a relatively cheap 3-stop round glass filter.

Tiffen 52mm ND 0.9 Filter (3-Stop) 52ND9 B&H Photo Video (bhphotovideo.com)

Here is a 84 mm x 84 mm 3-stop ND resin filter

https://www.bhphotovideo.com/c/product/155747-REG/Cokin_CP154_P154_Gray_Neutral_Density.html/?ap=y&smp=y&smpm=ba_f2_lar&lsft=BI:514&gclid=EAIaIQobChMI1e-vqqmTgAMVSufjBx2ZwwjbEAQYASABEgJWvvD_BwE

3” x 3” 3-stop ND polyester filter

https://www.bhphotovideo.com/c/product/102709-REG/LEE_Filters_9NDP3_3x3_Neutral_Density_ND.html

The Omega D2 lens plates and cones have a filter hanger attached. It’s reasonably easy to fashion a simple holder that holds your filter and attaches to the hanger by a single screw and nut. It your cone has lost its hanger, they’re easy to make one from a strip of sheet metal.

Here’s a photo of a DII/D2 cone with a lens disc and the filter hanger attached to the cone at the side.

https://www.ebay.com/itm/3049770135...MIpvG-gaGTgAMVWc3CBB0PJAnSEAQYBSABEgK7k_D_BwE

 

[Paul Howell]

I use standard GE LED bulbs, I would try a low out put LED bulb, like a 40 watt equivalent. I use a 75 and 150 equivalents without issues.

 

[Philippe-Georges]

I have set of old AGFA-Gevaert 15x15cm ND filters, these are resin made (Wratten imitations?) and meant for use in front of the lens but apparently resist to the heat of the bulb and don't fade, so they do the job perfectly...

I have tried LED bulbs too (Orsram), but there is something odd going on, like an afterglow or so...
Anyway, the difference between the teststrips and the final print was too large!

 

[Doremus Scudder]

I've simply used the same ND filters I use on my taking lenses over my enlarger lenses to reduce EXTEND exposure time when printing very small. I too like 20-30 second exposure times.

This means either a dedicated stepping ring, a push-on type filter holder or, in my case, gaffer's tape to hold the ND filter on the lens. Since I don't print very small very often, the tape was fine, but the OP may want a more permanent solution.

Of course, an ND gel of optical quality in the filter pack below the lens would work as well. Whatever is easiest. An ND filter is really the best option here IM-HO.

Doremus

 

[GregY]

I've simply used the same ND filters I use on my taking lenses over my enlarger lenses to reduce exposure time when printing very small. I too like 20-30 second exposure times.

This means either a dedicated stepping ring, a push-on type filter holder or, in my case, gaffer's tape to hold the ND filter on the lens. Since I don't print very small very often, the tape was fine, but the OP may want a more permanent solution.

Of course, an ND gel of optical quality in the filter pack below the lens would work as well. Whatever is easiest. An ND filter is really the best option here IM-HO.

Doremus

"to reduce exposure time"...... to extend exposure time?

 

[mshchem]

211 is an ordinary medium base Edison socket. I have a bunch of 25W, 15W and even 7 1/2 W tungsten bulb from safelights, contact printers etc. That's what I'd try, or a dimmer. Develop film to normal density

 

[C-130 Nav]

Thanks all for the inputs and good advice. I think I’ll go the ND filter route. My lens mounts have the below-the-lens holder brackets and I have the Omega holder for 2 inch square filters (Omega part number 7408, later replaced by 7142, then 429-023). I should be able to easily place a ND filter there. I plan not to go the voltage reduction and LED bulb route to avoid the known concerns with those. I may try a slower FB paper at some point.

 

[NedL]

I think you understand this, but using the longer lens does nothing to decrease the light intensity or increase exposure times - it just gives you more room under the lens and (usually) a few more options for small apertures.
Can you put an ND filter on top of your condenser(s)? It won't be convenient to handle, but it might give you a long term solution.

ha! Of course you are right. I admit when I answered, I was thinking it would be higher so there'd be less light. I've never swapped lens to change the exposure time, so I shouldn't have answered without thinking more carefully

 

[Doremus Scudder]

"to reduce exposure time"...... to extend exposure time?

Yes, indeed! Sorry for any confusion; I've edited my post

 

[L Gebhardt]

A 20x24 sheet of ND gel is about $8 at B&H. Rosco E-Colour #299 ND 1.2 Filter will give you 4 stops when placed above the negative carrier (it's not optically clear enough below the lens). Then you can print at f/8 with approximately 16s exposures based on 2s at f/11.