35mm color enlarger for 4x5 b&w contact printing?

[Pere Casals]

I was wondering what distance you have your bulb and what exposure times you would recommend as a starting point for standard ilford multigrade paper?

It is the counter, you dim the light until your exposure time is around 10s to 20s, or what you prefer.

It is preferable that the light comes a bit "collimated", I place the bulb around 2m far from paper, under the bulb I place a plate with a 1" hole, the rays should come as perpendicular to the sheet as possible.

I've a lux meter, I adjust power to make arrive (initially) some 5 Lux on the contact frame.

You can use your smartphone with a lux meter App, in the front face it has a sensor that measures light for the screen auto-bright feature, the lux meter app takes the reading from there. That far it's not an authentic luxmeter because it lacks a dome, so the reading is very directional, anyway that reading can be a very good reference. You can locate the sensor by casting a tiny shadow o the top of the smartfone face, and looking at the reading in the app.

Remember that grades 4, 4.5 and 5 do require x2 the time than grades 00 to 3.5

[Bob Salomon]

It is the counter, you dim the light until your exposure time is around 10s to 20s, or what you prefer.

It is preferable that the light comes a bit "collimated", I place the bulb around 2m far from paper, under the bulb I place a plate with a 1" hole, the rays should come as perpendicular to the sheet as possible.

I've a lux meter, I adjust power to make arrive (initially) some 5 Lux on the contact frame.

You can use your smartphone with a lux meter App, in the front face it has a sensor that measures light for the screen auto-bright feature, the lux meter app takes the reading from there. That far it's not an authentic luxmeter because it lacks a dome, so the reading is very directional, anyway that reading can be a very good reference. You can locate the sensor by casting a tiny shadow o the top of the smartfone face, and looking at the reading in the app.

Remember that grades 4, 4.5 and 5 do require x2 the time than grades 00 to 3.5

Do you know that most incident light meters came with both a dome and a flat plate?
The flat plate is for metering when shooting flat subjects and the dome for 3D subjects,

[Mick Fagan]

An unrelated question, can you only buy 4x5 paper in the 1000 sheet boxes from ilford? I found a video from Tim Klein (creator of the sp-445) in which he used the sp-445 to develop contact prints with 4x5 paper, which I think is a really neat way to make contact prints without a full darkroom.

I didn't know about that clip, viewed it and it makes sense.

That said, I would suggest you think of obtaining a mostly dark, darkroom and adding a simple safelight. Similar to this is probably perfect. For years I did darkroom work at night with curtains drawn and a simple single orange type safelight bulb.

https://www.thefilmbloke.com.au/prod...c-darkroomoffd

Once you have that your possibilities are greatly enhanced. You can then safely (do a paper test first) cut with either scissors or with a roller guillotine, a cheaper small pack of larger paper into the exact correct size for your film holder(s). 8x10" paper will give you 4 sheets, 12x16" paper will give you 12 sheets and so on. Ilford paper can be bought in a 25 pack of 8x10" in this country, probably yours as well. I would also suggest you purchase resin Coated (RC) paper to start out.

Mick.

[fulltang]

I didn't know about that clip, viewed it and it makes sense.

That said, I would suggest you think of obtaining a mostly dark, darkroom and adding a simple safelight. Similar to this is probably perfect. For years I did darkroom work at night with curtains drawn and a simple single orange type safelight bulb.

https://www.thefilmbloke.com.au/prod...c-darkroomoffd

Once you have that your possibilities are greatly enhanced. You can then safely (do a paper test first) cut with either scissors or with a roller guillotine, a cheaper small pack of larger paper into the exact correct size for your film holder(s). 8x10" paper will give you 4 sheets, 12x16" paper will give you 12 sheets and so on. Ilford paper can be bought in a 25 pack of 8x10" in this country, probably yours as well. I would also suggest you purchase resin Coated (RC) paper to start out.

Mick.

That's a great idea, I actually did black out my second bedroom, but I'm still waiting on my trays to get here, so the sp-445 seemed like a really clean and east way to get started. I'm definitely going to cut down some of my 8x10 paper!

[Pere Casals]

Do you know that most incident light meters came with both a dome and a flat plate?
The flat plate is for metering when shooting flat subjects and the dome for 3D subjects,

OK, but still there is a flat plate.

The sensors in the smartphones have no plate require a very strong correction when light is directional (several x), compared with the lux meter, no problem if the smartphone sensor is used as a relative reference, or if correction vs the lux meter is applied, for the correction I simply take the readings with the lux meter and with the smartphone.

If been using the smartphone sensor as an spot meter on the easel, to guess the denstity key small spots would reach with certain exposure by checking the paper calibration.

[fulltang]

It is the counter, you dim the light until your exposure time is around 10s to 20s, or what you prefer.

It is preferable that the light comes a bit "collimated", I place the bulb around 2m far from paper, under the bulb I place a plate with a 1" hole, the rays should come as perpendicular to the sheet as possible.

I've a lux meter, I adjust power to make arrive (initially) some 5 Lux on the contact frame.

You can use your smartphone with a lux meter App, in the front face it has a sensor that measures light for the screen auto-bright feature, the lux meter app takes the reading from there. That far it's not an authentic luxmeter because it lacks a dome, so the reading is very directional, anyway that reading can be a very good reference. You can locate the sensor by casting a tiny shadow o the top of the smartfone face, and looking at the reading in the app.

Remember that grades 4, 4.5 and 5 do require x2 the time than grades 00 to 3.5

Thanks very much. Since I've never actually created a paper print before, I'm not really sure what I'm doing in regards to burning and dodging. Would it be possible to get an acceptable exposure using only the white channel?

[Pere Casals]

Thanks very much. Since I've never actually created a paper print before, I'm not really sure what I'm doing in regards to burning and dodging. Would it be possible to get an acceptable exposure using only the white channel?

Yes... with warm white light (3500k) you get a normal contrast grade 2.5 I guess.

You may start with a warm white LED bulb of (say) CRI 96 and placing Ilford contrast filters under light to have a good reference about what each grade does. With no filter you have contrast 2.5 aprox, with the 2.5 filter under the bulb you have have the same grade to double the exposure time to get the same, as the filter has a light transmission of the half.

All ilford filters from 00 to 3.5 have the same exposure, the double than using no filter. Filters 4, 4.5 and 5 require x2 more exposure time than filters 00 to 3.5, and x4 more than if using no filtrer. This is to have the same light grey tones, as you increase grade shadows get darker.


Here you have some tutorials:

https://www.youtube.com/watch?v=woXZb8gjG4o

https://www.youtube.com/watch?v=EwDyB25-IeQ

https://www.youtube.com/watch?v=aNx66le363g

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


First you have to learn to make test strips.

If you have never printed perhaps it would be interesting that you start controlling contrast by using ilford contrast filters, later you may use the RGB bulb for convenience, when you are familiar with what each filter grade does then you may try to obtain the same with the RGB channels.


Feel free to ask anything, I'm still a learner but I'd be happy if I can help.

[fulltang]

Yes... with warm white light (3500k) you get a normal contrast grade 2.5 I guess.

You may start with a warm white LED bulb of (say) CRI 96 and placing Ilford contrast filters under light to have a good reference about what each grade does. With no filter you have contrast 2.5 aprox, with the 2.5 filter under the bulb you have have the same grade to double the exposure time to get the same, as the filter has a light transmission of the half.

All ilford filters from 00 to 3.5 have the same exposure, the double than using no filter. Filters 4, 4.5 and 5 require x2 more exposure time than filters 00 to 3.5, and x4 more than if using no filtrer. This is to have the same light grey tones, as you increase grade shadows get darker.


Here you have some tutorials:

https://www.youtube.com/watch?v=woXZb8gjG4o

https://www.youtube.com/watch?v=EwDyB25-IeQ

https://www.youtube.com/watch?v=aNx66le363g

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


First you have to learn to make test strips.

If you have never printed perhaps it would be interesting that you start controlling contrast by using ilford contrast filters, later you may use the RGB bulb for convenience, when you are familiar with what each filter grade does then you may try to obtain the same with the RGB channels.


Feel free to ask anything, I'm still a learner but I'd be happy if I can help.

Fantastic information, once again. I'm curious, would the white channel on the party bulb work? It's not a problem if it won't, I can go get a different warmer bulb and use the party bulb as a safelight until I have a good understanding of the process.

[Pere Casals]

the white of the rgb bulb will work, but it may not deliver contrast grade 2.5, probably it will deliver a more contrasty grade