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Thread: Fluorescent Grow Light Bulbs for alternative printing.

  1. #1

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    Fluorescent Grow Light Bulbs for alternative printing.

    I have a light fixture for alternative printing and I am wondering if these Fluorescent tube are of the correct wavelength?

    8-Pack AgroMax 4 Foot (45.75") Pure PAR Veg T5 Fluorescent Grow Light Bulbs - (8) F54T5HO Bulbs
    by HTGSupply

    These are from Amazon.

    My light fixture is designed for the T5 size of Fluorescent tubes.

    Thanks in advance.

    Gary
    "People take different roads seeking fulfillment and happiness. Just because they're not on your road doesn't mean they've gotten lost." - H. Jackson Brown

  2. #2
    Vaughn's Avatar
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    Re: Fluorescent Grow Light Bulbs for alternative printing.

    Google the company that make the lamps -- they usually will have the wave lengths graphed out.

    PS. Most units I have worked with use the BL tubes...cheaper and as effective (if not more) than the BLB.

    Edited to add. I wish Agromax would have included the spectrum output of their lights on their site. I am hesitant to recommend the AgroMax Pure UV T5 Bulb – 4 Foot tube. Besides UVA (320-400), it is designed to emit UVB (280-320), which alt processes in general are sensitive to, but 1) it is damaging to skin and eyes and 2) if you are using a contact printing frame with glass, most of that UVB will be blocked by the glass*....so one might be exposing oneself to damaging rays that aren't helping much.

    The AgroMax Pure PAR Veg T5 Fluorescent Grow Light Bulbs seem to be a better choice of the two, depending what its output really is. BL tubes peak at 350.

    * 95% as per Sandy King...https://sandykingphotography.com/res...s-for-printing
    Last edited by Vaughn; 28-Aug-2019 at 13:54.
    "Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China

  3. #3

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    Re: Fluorescent Grow Light Bulbs for alternative printing.

    I can’t speak to that specific bulb as to wether it will work or not, but looking at the spectrum it seems the wavelengths may be too long as there isn’t much output below 400nm. I also use a grow light as my exposure unit. There are two bulbs that’s I know work, at least for cyanotype and pt/pd. They are:

    1. AgroMax Pure UV T5 Bulb – 4 Foot
    These have an emission peak at around 365nm with a pretty narrow spectrum. They work well if you are using in camera negatives, however they tend to produce long exposure times (30mins for a cyanotype) when using digital negatives printed on pictorico as it blocks a significant portion of the up output.

    2. Eye Hortilux Power VEG 420
    These have an emission peak around 420nm. These work well for both in camera and digital negatives on pictorico and gives very fast exposure times, in the 2-4 minute range for pt/pd and 6-8 for cyanotype from a distance of around 6 inches. The pt/pd exposure times are probably too fast and I am considering moving the light further as I think I loose shadow contrast with an exposure that short.

    I hope this helps.

    Nick

  4. #4

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    Re: Fluorescent Grow Light Bulbs for alternative printing.

    Quote Originally Posted by NHE View Post
    I can’t speak to that specific bulb as to wether it will work or not, but looking at the spectrum it seems the wavelengths may be too long as there isn’t much output below 400nm. I also use a grow light as my exposure unit. There are two bulbs that’s I know work, at least for cyanotype and pt/pd. They are:

    1. AgroMax Pure UV T5 Bulb – 4 Foot
    These have an emission peak at around 365nm with a pretty narrow spectrum. They work well if you are using in camera negatives, however they tend to produce long exposure times (30mins for a cyanotype) when using digital negatives printed on pictorico as it blocks a significant portion of the up output.

    2. Eye Hortilux Power VEG 420
    These have an emission peak around 420nm. These work well for both in camera and digital negatives on pictorico and gives very fast exposure times, in the 2-4 minute range for pt/pd and 6-8 for cyanotype from a distance of around 6 inches. The pt/pd exposure times are probably too fast and I am considering moving the light further as I think I loose shadow contrast with an exposure that short.

    I hope this helps.

    Nick
    Nick, thank you for the very informed response.

    I was researching the AgroMax Pure UV T5 Bulb – 4 Foot and that is what prompted my question.

    Thanks again
    Gary
    "People take different roads seeking fulfillment and happiness. Just because they're not on your road doesn't mean they've gotten lost." - H. Jackson Brown

  5. #5

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    Re: Fluorescent Grow Light Bulbs for alternative printing.

    Thank you Vaughn and Nick for your responses.

    Gary
    "People take different roads seeking fulfillment and happiness. Just because they're not on your road doesn't mean they've gotten lost." - H. Jackson Brown

  6. #6

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    Re: Fluorescent Grow Light Bulbs for alternative printing.

    After some time printing I feel I should update my opinion of these bulbs and that I can not really recommend either of these bulbs. The 420nm bulb tends to fog with even slight over exposure, you can work around it with digital negatives but even so the results can be inconsistent. The pure UV bulb works much better however the UV output is mostly in a region which is not useful and it tends to produce a large amount of ozone during exposure which in my small darkroom is not a good thing.
    I have since moved on to LEDs which produce light in the 365-370nm wavelength with good results.

  7. #7

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    Re: Fluorescent Grow Light Bulbs for alternative printing.

    I'm with VAughn - BL bulbs seem to work best for the various alt processes I utilize.

  8. #8

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    Re: Fluorescent Grow Light Bulbs for alternative printing.

    NHE - can you please be specific as to what LED bulbs you have moved on to using that you feel have given you the results you are looking for, how many, and at what distance from your support you have placed them? Also, what exposure time have you been using? I have four fluorescent fixtures holding 2 bulbs each of F-40T12BL 40 Watt - T12 tubes (they are 48 inches). I have them about 5 inches away from the support. I make a digital negative with either Pictorico or Fixxons film and expose the cyanotype for 30 minutes. I am hoping to find a better "LED" bulb that makes my exposure go quicker.

  9. #9
    William Whitaker's Avatar
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    Re: Fluorescent Grow Light Bulbs for alternative printing.

    Quote Originally Posted by Lisa K View Post
    NHE - can you please be specific as to what LED bulbs you have moved on to using that you feel have given you the results you are looking for, how many, and at what distance from your support you have placed them? Also, what exposure time have you been using? I have four fluorescent fixtures holding 2 bulbs each of F-40T12BL 40 Watt - T12 tubes (they are 48 inches). I have them about 5 inches away from the support. I make a digital negative with either Pictorico or Fixxons film and expose the cyanotype for 30 minutes. I am hoping to find a better "LED" bulb that makes my exposure go quicker.
    +1, please.

  10. #10

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    Re: Fluorescent Grow Light Bulbs for alternative printing.

    Quote Originally Posted by Lisa K View Post
    NHE - can you please be specific as to what LED bulbs you have moved on to using that you feel have given you the results you are looking for, how many, and at what distance from your support you have placed them? Also, what exposure time have you been using? I have four fluorescent fixtures holding 2 bulbs each of F-40T12BL 40 Watt - T12 tubes (they are 48 inches). I have them about 5 inches away from the support. I make a digital negative with either Pictorico or Fixxons film and expose the cyanotype for 30 minutes. I am hoping to find a better "LED" bulb that makes my exposure go quicker.
    I use a 20W UV LED with a wavelength in the ~390nm range (I don't remember which it was exactly, like not under 380 and definitely not over 395, in any case 400nm should be considered a hard cutoff, absolutely nothing over that). It can expose an 8x10 cyanotype on an average of around 10-12 minutes at a distance of approximately 12", most other processes are much faster, well under 10 minutes for Argyrotype, about 5-6 minutes for gum prints. Did a platinum last night in 5 minutes...

    The LED is mounted to a large heatsink and it is powered by a 20w LED driver module that runs directly from AC mains. I control it with a standard GraLab darkroom timer. It has been very reliable for me for about 3 years now. No one should be using fluorescents in this day and age.

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