Durst L1200

[David Aimone]

Being somewhat new to this in my just completed darkroom, I actually used my Durst Enlarger yesterday for the first time, and I'm able to get decent results, but there seem to be a few unusual limitations that I wanted to ask about. It has the Varipoint Condenser Head on it.

First, with the varipoint light source, I can't seem to get the aperture closed down farther than about f/11 on the Schneider 105mm without all kinds of dark brown and blue distortions showing on the projection. Open f/11 and wider I can adjust the light source so it's fairly even. I have no idea what's going on here. Other enlargers that I've used haven't had this type of light source, so I haven't experienced this issue.

Second, when I'm trying to print on 5x7, it's very difficult to see the entire negative projected AND get it in focus. Also, the corners have less light than the middle. Should I try a lens other than the 150mm, or will that not help?

Third, when turning the enlarger "on", it takes anywhere from 1-3 seconds for the light to fully come one (less time if turned on very recently, more time if off for a while). Also, the bulb does take time to fade, but not as long. Is this normal? I seem to be able to guestimate times, but it makes it hard to use the 3 second interval method for burning and dodging.

I'm hoping this head with work for black and white printing. Otherwise, I might look for a CLS 501 head.

Any advice?

[gary mulder]

maybe you have the wrong condensers installed. 1 sec exposer is a quick way to zap your light bulb. Try leaving it on.

[David Aimone]

Gary,

I can double check, but I'm 99% sure it's the correct condenser assembly. The second part of your reply I don't quite understand.

David


maybe you have the wrong condensers installed. 1 sec exposer is a quick way to zap your light bulb. Try leaving it on.

[Nathan Potter]

David, I concur with Gary. Make sure the correct condensers for your particular light source are in place. If you are sure of this then I would suspect that you will need to adjust the distance between the lower condenser and the lens. At small apertures you are vignetting the illumination from the light source which results in the fringing (dark blue and brown shadow areas) in the projected image, just as you describe.

I am assuming that the varipoint light source is really an adjustable point source, so as you approach a true point source it becomes much more difficult to evenly illuminate the field of view of the film. However it should be feasible with a 150 mm enlarging lens. I can do it with both a 150 and 135 but with a hair of vignetting at the corners.

I believe Gary is suggesting that you run the bulb continuously while in use but toggle the light source using a shutter or a hand operated light block or some other mechanism. In such a case you will need to have a completely dark enlarger environment while the enlarger light source is on to avoid pre-exposing the paper.

My advice would be to increase the diameter of the light source to maximum (if this is really adjustable) since that will decollimate the illumination light and result in much reduced imaging of defects. Were you to use the light source at very small aperture you would need to be scrupulous about dust control.

Nate Potter, Austin TX.

[David Aimone]

Thanks, Nathan. I will try adjusting things again. I don't know if this is helpful, but I've taken a few photos of the setup on the head.

http://farm5.static.flickr.com/4130/5219332358_9b875f1d15_z.jpg
http://farm5.static.flickr.com/4126/5219332028_4679ca3293_z.jpg
http://farm5.static.flickr.com/4128/5219331718_8d7afed828_z.jpg

The second photo shows the varipoint bulb in the top of the head. The first photo shows the adjustment knob. The lower one moves the bulb front to back, while the upper moves it up and down and sideways.

The third photo shows the condenser arrangement. The 151 and 152 are stacked and the curved surfaces are facing each other.

Let me know if this helps.

Thanks!

David

[Donald Miller]

The point light source is very critical in it's focus. I have not worked with this particular source but I have converted a 138S into a point source and it is wonderfully sharp and very finicky on adjustment.

A 105 focal length lens is the wrong lens to use with the condensors that you have. Not only is the right focal length critical but on my 138S there is difference between differing manufacturers of the same focal length.

[David Aimone]

I'm sorry, that was a typo. I'm using a 150mm Schneider!


The point light source is very critical in it's focus. I have not worked with this particular source but I have converted a 138S into a point source and it is wonderfully sharp and very finicky on adjustment.

A 105 focal length lens is the wrong lens to use with the condensors that you have. Not only is the right focal length critical but on my 138S there is difference between differing manufacturers of the same focal length.

[Cor]

David,

I have the same enlarger (you removed the lid of the head which has a 45deg mirror, right?). I use a photcrescenta lamp such as:

http://www.photowarehouse.co.nz/bulb-p3-4-240v-150w-photocrescenta-/

Not sure if I run a 150 watt though, might be 75 watt, anyway this lamp gives none of the problems you describe. A point source sound like a pain, not sure if it is really worth the hassle..

best,

Cor

Btw these lamps run for a long time, but perhaps stock up, tungsten bulbs like this are gradually phases out

[David Aimone]

Yes, the 45 degree mirror is there.

Cor, that link doesn't work. Do you have more information on the bulb type? Is this a non-point source type bulb?

[Cor]

That is weird, it works for me,
anyway try http://www.foto-r3.com/en/philips-photocrescenta-75w-enlarger-lamp.html

or a Google search with photocrescenta.

These are ordinary tungsten light bulbs, but they are coated on the inside with some white powder, do not think that frosted is the right description.

The idea is that these lights have a very uniform diffuse spreading of light. I believe a frosted lamp can be used, but the printed label on the glass bulb can show up..

Best,

Cor

Btw they are not point sources


Yes, the 45 degree mirror is there.

Cor, that link doesn't work. Do you have more information on the bulb type? Is this a non-point source type bulb?

[ic-racer]

Yes, the 45 degree mirror is there.

Cor, that link doesn't work. Do you have more information on the bulb type? Is this a non-point source type bulb?

The link worked for me. it showed a "standard" enlarger bulb, not a "point source" bulb.

If it were me, I'd try a bulb like that. I think the point source will just drive you crazy with film defects and dust, even if you did get it focused properly.

This is similar to what is in the link Cor posted: http://www.replacementlightbulbs.com/lampph212.html

[David Aimone]

Thanks! I may give one of these a try. Cheap enough. Now I just have to check if the 120V is appropriate or if the power supply is bumping it to 220V


The link worked for me. it showed a "standard" enlarger bulb, not a "point source" bulb.

If it were me, I'd try a bulb like that. I think the point source will just drive you crazy with film defects and dust, even if you did get it focused properly.

This is similar to what is in the link Cor posted: http://www.replacementlightbulbs.com/lampph212.html

[nolindan]

You have a point-source head. You need to use a point-source lamp. Do not try (or bother to try) any other lamp with this head - it won't work. Changing the lamp will not make it into a regular head.

A point source only works with the lens wide open (or close to wide open).

A point source works by projecting (shadowing might be a better term) the image of the negative onto the back of the lens. Obviously, if you stop the lens down you block the peripheral rays and therefore block the periphery of your negative.

Try it with the lens wide open.

If you are using it with the lens it came with - the one for the point-source head - then all should be well.

A point source will give a very, very sharp image. Every minute scratch and speck of dust will be imaged with the extreme clarity. This feature, along with the need to use the lens wide open (and the need to use an APO lens for best results when wide open (and the need to use a glass carrier to hold the negative flat what with the limited DOF of a wide-open lens)) make point source heads unpopular for general use.

However, if you are willing to be scrupulous with your technique point-source heads do produce stunning results.

As to turn-on/off time for the lamp - this is normal with this lamp. There should be a shutter somewhere in your kit or already installed on the enlarger. The timer controls the shutter. You turn the lamp on before and after the exposure is timed.

I don't know who thought up the 3-second blip method of dodge and burn but they should be shot at dawn, and again several times at sunset for good measure. 3 seconds in a 10 second exposure is close to one full zone-system zone's worth of tone.

[David Aimone]

Fair enough on the 3 second thing. Haven't used it, but had considered trying it.

The enlarger came with everything but the lens. I purchased a 150mm APO Schneider enlarger lens for it. There doesn't seem to be a separate shutter for the enlarger. The timer just turns the light on and off.

I should use the lens all the way wide open? Not stopped down a small bit for DOF? I can try that.

If I wanted to get a different head for this enlarger down the road, would a CLS 501 or a VLS 501 be the appropriate choice?

David


You have a point-source head. You need to use a point-source lamp. Do not try (or bother to try) any other lamp with this head - it won't work. Changing the lamp will not make it into a regular head.

A point source only works with the lens wide open (or close to wide open).

A point source works by projecting (shadowing might be a better term) the image of the negative onto the back of the lens. Obviously, if you stop the lens down you block the peripheral rays and therefore block the periphery of your negative.

Try it with the lens wide open.

If you are using it with the lens it came with - the one for the point-source head - then all should be well.

A point source will give a very, very sharp image. Every minute scratch and speck of dust will be imaged with the extreme clarity. This feature, along with the need to use the lens wide open (and the need to use an APO lens for best results when wide open (and the need to use a glass carrier to hold the negative flat what with the limited DOF of a wide-open lens)) make point source heads unpopular for general use.

However, if you are willing to be scrupulous with your technique point-source heads do produce stunning results.

As to turn-on/off time for the lamp - this is normal with this lamp. There should be a shutter somewhere in your kit or already installed on the enlarger. The timer controls the shutter. You turn the lamp on before and after the exposure is timed.

I don't know who thought up the 3-second blip method of dodge and burn but they should be shot at dawn, and again several times at sunset for good measure. 3 seconds in a 10 second exposure is close to one full zone-system zone's worth of tone.

[David Aimone]

Just checked—there's definitely no shutter in this enlarger. The power goes directly from the timer and power supply to the bulb.

[David Aimone]

:confused:

Ok, according to the old Durst catalog, the "Multigraph" version head has a shutter, but the L1200 BW and L1200 Varipoint do not. I have the Varipoint.

So, how do I control exposure accurately? Should I look for a Multigraph or another head (CLS 501 or VLS 501)?

This is very confusing and I'm really desperately trying to get a basic system going here that I can depend on!

THANKS THANKS THANKS for any further direction in advance!

[nolindan]

Just checked—there's definitely no shutter in this enlarger.

Hmmm, bit of a bummer.

If printing times so short that the warm-up/cool-down of the lamp causes problems you may want to have a neutral density filter in the light path to slow down exposure.

The Darkroom Automation timer (http://www.darkroomautomation.com/fst.htm) [shameless plug] has a feature that allows compensation for a lamp's on/off times.

You can find out what your lamp is doing to your exposure timing accuracy with this procedure on the Darkroom Automation support files section:

http://www.darkroomautomation.com/support/AppNotePH212LampDelay.pdf

[Nathan Potter]

David, I should have pointed out what Nicholas has so clearly stated. Point source setups are configured so that the full ray path from the condenser needs to illuminate the full area of the film but at the same time that ray bundle is highly convergent at the back of the lens. Thus the enlarging lens aperture is nonfunctional at typically wider than about f/11. I use my point source at f/5.6 and change light intensity by driving the lamp (a halogen bulb) using a variac and a low voltage transformer.

I am however not familiar with your enlarger, but I suspect you will need to dim your light source somehow in order to get adequate long exposure times since the f/stops are most always nonfunctional with the point source arrangements. It sounded like in your original post that your enlarger has an aperture adjustment at the bulb providing for control of the size of the point source. In optics and especially microscopy this is characterized as the f/stop of the light source and is used to control the degree of collimation of the source illumination.

The point source setups I use with D2V enlargers use waterhouse mechanical stops of various sizes - a setup sometimes referred to as psuedo point sources. As mentioned, the problem with point source type illumination is that very small diameter light sources yield very high contrast images and at the extreme provide almost no intergrain light modulation at all - every defect is perfectly imaged. With fanatical dust control however the image acuity is simply astounding and with the ability to change the size of the point one can introduce varying degrees of grain modulation and hence manipulate print contrast.

Changing the intensity of the lamp is a headache in working with color since that changes the color temperature of the exposing light. With Ilfochrome and variable contrast B&W paper I pick an intensity that will give me adequate time for dodge and burn manipulations, say 30 seconds and stick with that intensity. I use the variac to crank up the intensity while doing critical focusing.

Nate Potter, Austin TX.

[David Aimone]

That timer looks interesting. Is that a maximum delay of 99 seconds or .99 seconds? It seems the enlarger bulb can sometimes take up to 3 seconds to fully activate if it hasn't been triggered within a few seconds prior.


Hmmm, bit of a bummer.

If printing times so short that the warm-up/cool-down of the lamp causes problems you may want to have a neutral density filter in the light path to slow down exposure.

The Darkroom Automation timer (http://www.darkroomautomation.com/fst.htm) [shameless plug] has a feature that allows compensation for a lamp's on/off times.

You can find out what your lamp is doing to your exposure timing accuracy with this procedure on the Darkroom Automation support files section:

http://www.darkroomautomation.com/support/AppNotePH212LampDelay.pdf

[David Aimone]

Nathan,

I can certainly use the widest aperture. The intensity is controllable through the variable power supply. There's no aperture adjustment of the bulb per se but the bulb can be moved closer to and farther from the condenser lenses, as well as moved in a sort of sideways spiral. I'm beginning to piece this mystery together, but very slowly.

Color printing won't be part of my routine, so the changes in color temperature shouldn't be an issue. This enlarger was originally purchased by a university microbiology lab around 1990.

Keep the ideas flowing!

David


David, I should have pointed out what Nicholas has so clearly stated. Point source setups are configured so that the full ray path from the condenser needs to illuminate the full area of the film but at the same time that ray bundle is highly convergent at the back of the lens. Thus the enlarging lens aperture is nonfunctional at typically wider than about f/11. I use my point source at f/5.6 and change light intensity by driving the lamp (a halogen bulb) using a variac and a low voltage transformer.

I am however not familiar with your enlarger, but I suspect you will need to dim your light source somehow in order to get adequate long exposure times since the f/stops are most always nonfunctional with the point source arrangements. It sounded like in your original post that your enlarger has an aperture adjustment at the bulb providing for control of the size of the point source. In optics and especially microscopy this is characterized as the f/stop of the light source and is used to control the degree of collimation of the source illumination.

The point source setups I use with D2V enlargers use waterhouse mechanical stops of various sizes - a setup sometimes referred to as psuedo point sources. As mentioned, the problem with point source type illumination is that very small diameter light sources yield very high contrast images and at the extreme provide almost no intergrain light modulation at all - every defect is perfectly imaged. With fanatical dust control however the image acuity is simply astounding and with the ability to change the size of the point one can introduce varying degrees of grain modulation and hence manipulate print contrast.

Changing the intensity of the lamp is a headache in working with color since that changes the color temperature of the exposing light. With Ilfochrome and variable contrast B&W paper I pick an intensity that will give me adequate time for dodge and burn manipulations, say 30 seconds and stick with that intensity. I use the variac to crank up the intensity while doing critical focusing.

Nate Potter, Austin TX.

[nolindan]

That timer looks interesting. Is that a maximum delay of 99 seconds or .99 seconds?

It is 0.99 seconds. It isn't much problem to supply a timer with a longer range if you need it.

Don't forget that the afterglow will compensate for some of the warm up time.

Try the experiment in the application note to find out how much compensation you need. You might want to use 20 x 3 second exposures compared to one 60 second exposure so the lamp has time to reach full brightness. If you use a sequence of 't' second exposures then:

Delay time = ((n - 20) * t)/(n - 1)

[David Aimone]

I will do this when I have a chance soon...thanks


It is 0.99 seconds. It isn't much problem to supply a timer with a longer range if you need it.

Don't forget that the afterglow will compensate for some of the warm up time.

Try the experiment in the application note to find out how much compensation you need. You might want to use 20 x 3 second exposures compared to one 60 second exposure so the lamp has time to reach full brightness. If you use a sequence of 't' second exposures then:

Delay time = ((n - 20) * t)/(n - 1)

[36cm2]

I have the L1200 with a CLS head. It too has a delay, but it's more like half a second and is fairly consistent. While the varipoint may differ, 3 seconds is a long delay (more than the RH Design Stop Clock timer will compensate for) and it seems odd that it vacillates so much in terms of delay. Don't lose faith in the enlarger, it is just awesome. Sound like you need to work the kinks out.

Best regards,
Leo

[David Aimone]

Will a replacement bulb help? I have no idea how old the bulb in there is, or if that makes a difference...


I have the L1200 with a CLS head. It too has a delay, but it's more like half a second and is fairly consistent. While the varipoint may differ, 3 seconds is a long delay (more than the RH Design Stop Clock timer will compensate for) and it seems odd that it vacillates so much in terms of delay. Don't lose faith in the enlarger, it is just awesome. Sound like you need to work the kinks out.

Best regards,
Leo

[Steve Sherman]

Hi David,

Apologies for this getting to be such a hassle.

I seem to remember the power supply has a type of rheostat switch which I would imagine may well have an effect on the light. I believe the rheostat can completely dim the light while not technically shutting off the light.

Cheers

[David Aimone]

Hey Steve,

Don't feel bad at all! It's just one of many challenges as I learn the craft side of film photography.

It does have a controllable rheostat, but it still takes a long time for the bulb to come on even when turning the control down and then up again.

David

[ic-racer]

I just found the Varipoint manual pdf (pm me if you need a copy) and here are a few clarifications:
It looks like the electronic shutter is "OPTO-TIM" and was an accessory (super rare??)
The point source bulb is 100W 12V and needs to run off the appropriate power supply.
It does look like the 'standard' condenser setup (Femokit) uses the same lamphouse as the Varipoint, with a 120V opal lamp, without the 12V power supply.
Your condenser combo of 152 and 151 is optimized for 1.2x to 7.3x magnification of 4x5 negatives with a 150mm lens.
As Nicholas indicated, lens is to be used wide open.
For centering the bulb base screws in and out.

From the manual:


VARIPOINT 1200
Condenser illumination system using point source of light for razor-sharp rendering of details and increased contrast.
APPLICATION--for printing negatives lacking contrast and electron-microscope negatives.

[Cor]

David,

I think your set up is confusing you, judging from your photo's and description I am pretty sure that you have the standard lamphouse for a standard opal/photocrescenta lamp, only the lamp you are runnning now is for a point source.

I believe that you can make your life easier if you would screw in a normal frosted lamp (if that fits in the base) and hook it up with an standard (in your case 120V) wire and run that lamp of say 75 watt, and than see if you can project an even illuminated and sharp image from a negative on your base board. If so, buy an opal lamp and be happy.

Best,

Cor

[David Aimone]

It's amazing the range of opinions on the subject of this enlarger! Still, I thank each of you for your input. Eventually, all this will help me to figure it all out...

Cor, how can you tell this setup is for a standard frosted bulb? Norlinden states this can only be used with a varipoint bulb...but I will try both approaches.


David,

I think your set up is confusing you, judging from your photo's and description I am pretty sure that you have the standard lamphouse for a standard opal/photocrescenta lamp, only the lamp you are runnning now is for a point source.

I believe that you can make your life easier if you would screw in a normal frosted lamp (if that fits in the base) and hook it up with an standard (in your case 120V) wire and run that lamp of say 75 watt, and than see if you can project an even illuminated and sharp image from a negative on your base board. If so, buy an opal lamp and be happy.

Best,

Cor

[Cor]

David,

If you go to:

www.prepressexpress.com/downloads/DurstL1200Manual.pdf

(a thank you to IanMazursky and I shouldn't forget IC-Racer too)

You can download an extensive manual, and you'll see that the lamphouse/head for Varipoint1200 and for the Femokit (the opal bulb) is the same, as well as I could judge from the images you've posted (I have the Femokit).

As I said before: try to replace that point source lamp with an ordinairy frosted lamp, check and than buy an opal lamp

Best,

Cor

A clear tungsten bulb probably will not work, you;ll project the wire/filament

[David Aimone]

Cor, is this one suitable?

http://www.replacementlightbulbs.com/lampph213.html


David,

If you go to:

www.prepressexpress.com/downloads/DurstL1200Manual.pdf

(a thank you to IanMazursky and I shouldn't forget IC-Racer too)

You can download an extensive manual, and you'll see that the lamphouse/head for Varipoint1200 and for the Femokit (the opal bulb) is the same, as well as I could judge from the images you've posted (I have the Femokit).

As I said before: try to replace that point source lamp with an ordinairy frosted lamp, check and than buy an opal lamp

Best,

Cor

A clear tungsten bulb probably will not work, you;ll project the wire/filament

[Cor]

yup that's a good one, not sure if it would fit the socket in the lamphouse, there is a mission for you..;-)..

Best,

Cor

[David Aimone]

Actually, would this one be better (longer life, 150w instead of 250w)?

http://www.replacementlightbulbs.com/lampph212.html


yup that's a good one, not sure if it would fit the socket in the lamphouse, there is a mission for you..;-)..

Best,

Cor

[ic-racer]

The Durst PULAMP 12v 100W bulb you have uses a standard screw socket. (new lamp $75 so keep it somewhere :) )

I believe all you need to do is change the cord to one suitable for 120V, and the socket will be the same.

Here is a related thread discussing your same problem:

http://photo.net/black-and-white-photo-printing-finishing-forum/007Opu

[David Aimone]

Thanks, I read the discussion. Looks like I'll try it. I'm not sure where I would place the bulb in the head, how adjustable it would have to be, and I assume the mirror would still reflect the light....

so many questions!


The Durst PULAMP 12v 100W bulb you have uses a standard screw socket. (new lamp $75 so keep it somewhere :) )

I believe all you need to do is change the cord to one suitable for 120V, and the socket will be the same.

Here is a related thread discussing your same problem:

http://photo.net/black-and-white-photo-printing-finishing-forum/007Opu

[ic-racer]

You will still adjust it for even light, but there will probably be a larger distance of bulb locations over which the light pattern on the baseboard is acceptable.

[David Aimone]

Ordered two bulbs. I'll see how it works.

Also, I will do the calculation for the time for the point source bulb to come on. i can see which approach will work best.

It's coming together, I think...

[Cor]

Ordered two bulbs. I'll see how it works.

Also, I will do the calculation for the time for the point source bulb to come on. i can see which approach will work best.

It's coming together, I think...
David,

just checked mine, I run a 150 watt lamp, max is 250 watt but the manual warns against running it too long because of the heat generated, and you wanted longer printing times, right?

best,

Cor

[David Aimone]

Ok, an update:

Have the bulbs to convert to non-point source, but haven't rigged anything up yet.

Meanwhile, I've been <practising> with the varipoint head. Here's the deal.

The varipoint head requires the lens to be fully open, meaning there's a LOT of light coming through. The power supply for the bulb is a dial from 0 to 10. If I use 10, the bulb comes on quickly, but exposure times are impractically short. If I set the dial to about 6, the light is much slower to come on, but exposure times are generally hovering around 7-10 seconds. Setting the dial to around 5 has the light coming on much slower still and about a 20 second exposure time. Less than five and the bulb seems very dim and inconsistent, but I do have to explore that range a bit more.

SO....it seems that I EITHER have almost instant bulb on and bright light but unusable exposure times; OR a bulb that takes 1-4 seconds to fully light up but longer, usable exposure times. To top it off, with the latter choice, it seems the bulb brightening time can vary depending on how long it has been since the last time turned on.

BOY I WISH THIS HAD THE OPTIONAL SHUTTER!

I'll play with this a bit more, and then see how adapting it for a non-varipoint bulb compares.

[David Aimone]

Following up on the last thread, I guess here is a question:

Is there another way of doing a test sheet with this situation?

I was taught to cover the paper every 2 or 3 seconds from a base time, but since the bulb takes almost this much time to come on (and less to go off), it seems that doing it this way would be very inaccurate. Do I need to find a way to mount a Packard on my enlarger lens?

[ic-racer]

BOY I WISH THIS HAD THE OPTIONAL SHUTTER!


One of these could be rigged up with a little work.

http://cgi.ebay.com/Electric-shutter-8-x-2-aperture-/250718790109?pt=Film_Cameras&hash=item3a600121dd#ht_500wt_922

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280530014100&ssPageName=STRK:MEWAX:IT#ht_1901wt_1141

[gary mulder]

I have a example of the second one. It is big, and will not fit inside the 1200 on top of the lens board.

[David Aimone]

OK, well I <think> I've solved a problem! Haven't actually printed yet, but looks promising. :D

I purchased a regular replacement lamp (not the point source lamp) for under $10; bought a bulb socket to plug adapater that will fit into the whole for the point source bulb lamp/wire; wrapped electrical tape around the outer housing to have a more secure fit in the hole; plugged it into a heavy duty extension cord and directly into my timer.

The image looks darn good, and the bulb comes on relatively instantly compared to the point source bulb!

I'm going to do some printing with it this afternoon.

Darn, I LOVE it when things work out fairly simply! If this does work as well as it looks, I guess I won't need to spend $$$ for a color head.

[ic-racer]

Yes, I suspect that should work fine.

[David Aimone]

Working great! Just may have to put a dimmer on the bulb somehow as I seem to be running 8-12 seconds at f/22. Or use a ND filter in the filter drawer.

[pergorm]

Hello David

Just happened to read this thread and learned about your problems. Try mounting your condensors correctly. They should be mounted flush with the bottom of the Femocap condensor-holder. They are not in your picture.
Also enjoy your coated condensors. They are hard to come by and they work well with a standard frosted bulb. And no need to work the lens on full aperture.

Regards
Per J

[David Aimone]

Thanks, Per J,

Things working very well with the regular frosted bulb and an F-stop darkroom timer.

David