Lumex, Footcandle, Shade, semishade, and Co...

[kavanaru]

I have seen lots of technical discussion here regarding Lumex, Footcandles, plants needing high or low light intensity and and so on...

I personally try to follow my feelings with the light and the (known) requirements of the plants, and try and error until my plants look happy... But...

is there a link to explain the footcandle needs of different plants, and or to translate the light intensity hints given by IOSPE into footcandle/lux?

For example, what exactly would "Full Shade", "Dappled shade or Partial Shade", "Bright Light or Full light", and "Full Sun" (IOSPE scale) mean in terms of Fc/Lux?

This would help many "newcomers" to understand the light intensity issues...

Depending on the feedback to this thread and the information given, this could probably be a good sticker

to help, a good link to measure light intensity without a luxometer:
Light Intensity Measurement
and one to convert Fc to Lux and viceversa (for those not wanting to multiply/divide by 10) :
Foot-Candles to Lux Conversion Calculator

[Sandy4453]

I am so glad you've asked this Ramon. I'm always wondering the same. Light requirements are so often left up to intrepretation and what I might consider, high, low, etc., may not be true to reaching the intensity required. I'm always wondering...

[Ross]

To some degree, that will be a very difficult task since "full shade" in Florida is no doubt much brighter than "dappled sunlight" or "part shade" at your latitude. I still contend a good light meter is a much better tool that word descriptions. I grow my Phal, Masdies, Paphs, etc right alongside my Brassias, Brassavola, Potinera, etc. All in a south window with full sun (when the sun shines.) I would never try that in Florida. I've never seen an exhaustive publication regarding foot-candles/lux needs of various orchids. I have seen a few mentioned in dealer ads, I have seen a few listed as representative of a type, etc. But a full listing. One's own experience counts for more, as Ramon says in the first post. Another thing one could use would be leaf color. I have a long discussion regarding similar issues on my blog Orchids by Ross: Lighting Issues

[kavanaru]

Hi Ross, that's teh point I wanted to raise here. IOSPE is recommended very often here as guideline for newbies, but I also agree that shade, semishade or full sun are always relative, and full sun in venezuela would fry almost all orchids (not Brassavola nodosa)

and thought maybe provide a wide guidance to all. something like:

Phals 1500Fc to 3000 Fc, Catts 3000 to 5000 Fc (Hey, I am just making up these numbers!!! and probably that's to high or to low!)

As I said, I normally judge myself with the plant self and my own experience but have never measured light at all (even thought, I am thinking of buying a luxometer for my other hobby, and if i do it, I will use it of course to measure the light my plants get)

[terryros]

This disucssion would be focused on the peak and valley approach to lighting that a window or greenhouse provide for orchids as compared to the constant light intensity that an artificial light grower achieves. Under artificial light the light intensity can be much less and still have success because of the constant light throughout the day. It may be the total illumination that a plant needs over the entire day period that matters.

[Jonna]

I was going to mention how difficult it is for me to judge light over the length of a day. When I see full sun I often wonder if they really mean the kind of sun we get here in the tropics or if it is some kind of shorthand for artificial light. I'm really glad that you who know are discussing this.

Just for me, I think knowing where the plant grows in the wild helps more. Is it up high in the canopy or low to the ground in dense jungle or in a sparse scrub type of cover.

[kavanaru]

ok, maybe re-directing this thread to a different goal... I will start compiling here here the information I find regarding light intesity needed for different plants (genus, especies, whatever).

Please note that this infor is collected from the web, and sometimes based on experience of other people. It should be used only as a reference and with care, and probably some experimenting will be needed when applying it to your culture.

I would also like to invite everybody to add his/her experience in the field.

few easy rules: 1) light intensity measured in Fc or lux, or at least any units more accurate than "semi partial full sun, raising on the south east, and the moon on top of the mango tree with parrots singing on the background" 2) Always add the sources of information, and if you have a link to it GREAT!

as soon as I find more info, I will add it here
here we go:

1.- 400-500 fc, for Draculas, Masdevallias, Paphiopedilum growing under a t5 unit 8 bulbs all together! (remember that some Paphs need higher lihght that others!) http://www.orchidboard.com/community...rum-2x4x4.html

2.- 2,000-4,000 footcandles (light shade to partial sun) for Mexipedium xerophyticum Mexipedium xerophyticum (I think this info is not for growing under artificial light, but am not sure!)

as soon as I find more info, I will add it here

[s.kallima]

Great idea Kavanaru, thank you for this thread !!!
Here is what I could find in my species culture sheets
(I did not include the AOS culture sheets because I find they give too big of a fc. range for the genus), let me know if the form is correct or if I should edit the post to format it differently :

1) 1200-1800 fc (bright shade, no direct sun) for Chiloschista usneoides, in Charles and Margaret Baker's free culture sheets (Orchid Culture - Charles and Margaret Baker)

2) 1500-2500 fc for Coelogyne mooreana (in C&M Baker)

3) 1500-2000 fc for Callista Group of Dendrobiums : species include aggregatum, chrysotoxum, densiflorum, farmeri and thyrsiflorum (in White Oak Orchids culture sheets: White Oak Orchids)

4) 2000 fc for the Oxyglossum group of Dendrobium include cuthbertsonii, hellwigianum, laveifolium, masarangense, seranicum, vexillarius, and violaceum (in White Oak Orchids culture sheets)

5) 2000-3000 fc for Coelogyne cristata and Coelogyne mossiae (in C&M Baker), for Dendrobium Group of Dendrobiums Dendrobium chrysanthum, friedricksianum, nobile, wardianum, anosum, crassinode, falconeri, fimbriatum, findlayanum, heterocarpum, loddigesii, moniliforme, parishii, primulinum, for Phalaenanthe group : include Dendrobium affine, bigibbum, dicuphum, phalaenopsis and williamsianum and most popular hybrids, also for the Spathulata group : antennatum, canaliculatum, discolor, gouldii, johannis, lineale, stratiotes, strebloceras, taurinum (in White Oak Orchids culture sheets)

6) 2000-3600 fc for Neofinetia falcata (in C&M Baker)

[s.kallima]

Here is a compilation of info from the free culture sheets on C.& M. Baker's website :

800-1500 fc. for Comparettia speciosa, Masdevallia datura

1000-2000 fc. for Miltoniopsis hybrids, Masdevallia angulata

1200-2000 fc. for most Miltoniopsis species, Aerangis luteo-alba, Aerangis punctata, Macroclinium bicolor, Masdevallia strobelii, Phalaenopsis lobbii

1200-2500 fc. for Ancistrochilus rothschildanus

1500-2500 fc. for Coelogyne nitida, Sievekingia marsupialis

1800-2500 fc. for Paphiopedilum armeniacum, Angraecum cultriforme, Coryanthes speciosa, Epigeneium lyonii, Psychopsiella limminghei, Psychopsis krameriana, Psychopsis papilio, Psychopsis sanderae, Psychopsis versteegiana

2000-3000 fc. for Acacallis cyanea, Encyclia prismatocarpa, Epidendrum parkinsonianum, Oncidium trulliferum, Zygopetalum mackayi

2000-3500 fc. Eulophia speciosa

2500-3000 fc. for Dendrobium crispilinguum, Domingoa haematochila

2500-3500 fc. for Brassavola nodosa, Cattleya skinneri, Chysis aurea, Cymbidium atropurpureum, Encyclia cordigera, Epidendrum schlechterianum, Laelia pumila, Oncidium onustum, Oncidium wentworthianum

2500-4000 fc. for Angraecum leonis, Barkeria barkeriola, Catasetum integerrimum

3000-4000 fc. Dendrobium bigibbum, Cymbidium erythrostylum, Euanthe sanderiana, Laelia briegeri, Laelia speciosa, Rhynchostylis gigantea, Vandopsis gigantea

3000-4500 fc. for Dendrobium phalaenopsis, Bifrenaria harrisoniae

3500-4000 fc. Coelogyne pandurata, Laelia tenebrosa

3500-4500 fc. for Dendrobium nobile, Schomburgkia galeottiana

3500-5000 fc. for Mesoglossum londesboroughianum

[Magnus A]

If my orchids should obey to these light recuirements they should never bloom! But they do!

There is a huge different between reported light intensities.

Some is maximum light at brightes time at the native growing place
Others are mean value over the day at the native site.

Never have I seen reports for artificial constant light intensitys for 12 hours.......

Very rarely are reports of minimum requirements.

My opinion is that this kind of list make more damage then good by telling beginers that they can not give enough light.