I'm thinking about buying this LED ring light for macro illumination.
Question: does the colour temperature change as you adjust brightness?
Any other comments re suitability welcome.
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Moderators: rjlittlefield, ChrisR, Chris S., Pau
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NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
LED's
NU,
Although I haven't used that particular ring light, I've used similar ones -- as well as other LED lighting sources in photography. In my experience, temperature color remains stable as intensity (brightness) is adjusted. Sorry to say I don't have any data/ measurements to offer -- just my observations that preset white balance seems to remain true despite change in brightness.
Did you happen to look at this site <http://www.cdfa.ca.gov/phpps/ppd/entomology/dome.html> which I posted a few days ago on the Macro/ Micro Technique forum? A very similar light (from the same company) is discussed, which differs, in part, by having more interior space (larger diameter) than the light you reference. This extra space was important to our needs for viewing insect specimens -- which is why I bring it up; you may have a completely different usage in mind, of course! The four-zone ability of your light is potentially quite nice. However, there is another ring light (same company) that is four-zone and larger yet: <http://www.gainexpress.com/product_info ... 4phi2t0fr6>. I have been using it recently, and like the extra interior space. Also, it is about 10mm lower in profile, which can be important in some circumstances. Although it has more LED's, they are smaller (3mm vs. 5mm), so the overall light is about the same (temperature is similar -- but maybe not exactly the same, though any difference seems invisible to Photoshop....). We use plastic domes painted white to reflect a soft light off the interior of the dome. A new technique -- not discussed on the web site -- seems quite promising. This involves using a dome that is lightly white-painted on the inside only, which allows an external flash to be used through the dome. The ring light + dome can then be used to illuminate the specimen -- for focusing, etc. -- then shut down, allowing final illumination to be provided by flash alone. Flash definitely seems to be necessary as magnification increases much above 5:1! I'm working on fixing a Macro Twin light to use from the end of some bellows in conjunction with a ring light/ dome set-up; hopefully I'll have some results to comment on soon.
Eric
Although I haven't used that particular ring light, I've used similar ones -- as well as other LED lighting sources in photography. In my experience, temperature color remains stable as intensity (brightness) is adjusted. Sorry to say I don't have any data/ measurements to offer -- just my observations that preset white balance seems to remain true despite change in brightness.
Did you happen to look at this site <http://www.cdfa.ca.gov/phpps/ppd/entomology/dome.html> which I posted a few days ago on the Macro/ Micro Technique forum? A very similar light (from the same company) is discussed, which differs, in part, by having more interior space (larger diameter) than the light you reference. This extra space was important to our needs for viewing insect specimens -- which is why I bring it up; you may have a completely different usage in mind, of course! The four-zone ability of your light is potentially quite nice. However, there is another ring light (same company) that is four-zone and larger yet: <http://www.gainexpress.com/product_info ... 4phi2t0fr6>. I have been using it recently, and like the extra interior space. Also, it is about 10mm lower in profile, which can be important in some circumstances. Although it has more LED's, they are smaller (3mm vs. 5mm), so the overall light is about the same (temperature is similar -- but maybe not exactly the same, though any difference seems invisible to Photoshop....). We use plastic domes painted white to reflect a soft light off the interior of the dome. A new technique -- not discussed on the web site -- seems quite promising. This involves using a dome that is lightly white-painted on the inside only, which allows an external flash to be used through the dome. The ring light + dome can then be used to illuminate the specimen -- for focusing, etc. -- then shut down, allowing final illumination to be provided by flash alone. Flash definitely seems to be necessary as magnification increases much above 5:1! I'm working on fixing a Macro Twin light to use from the end of some bellows in conjunction with a ring light/ dome set-up; hopefully I'll have some results to comment on soon.
Eric
Thank's Eric.
I took a look at your technique and examples, excellent account.
Your detailed reply answered a question that I should have asked first; i.e., the suitability of these LED's for the higher magnifications (5x +).
My biggest problem with illumination is for the high mag stuff with short working distance between lens and subject. At lower mags and longer WD I can get by with a flash.
So, as these LED's cannot be used effectively for the high mag images I will stay with electronic flash.
Thanks again, you saved me money and possible frustration.
I took a look at your technique and examples, excellent account.
Your detailed reply answered a question that I should have asked first; i.e., the suitability of these LED's for the higher magnifications (5x +).
My biggest problem with illumination is for the high mag stuff with short working distance between lens and subject. At lower mags and longer WD I can get by with a flash.
So, as these LED's cannot be used effectively for the high mag images I will stay with electronic flash.
Thanks again, you saved me money and possible frustration.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
LED's
You're welcome NU -- though sorry to discourage you on ring light, not my intention!
My comment on suitability for the dome light at over 5:1 mag should be explained further. I think these lights are useful at even higher mags than these but that flash will probably offer the highest resolution & detail (based on the many excellent images on this forum -- not on my own work; I'm just starting in this area...). I've included one image (single shot) of a butterfly wing taken with just the illumination of a 144 LED dome ring-light, using a Leitz 20x/.33 UM with a Leitz 6.3x Periplan eyepiece. This objective has about 14mm working distance, however the light will work down to as close as about 5mm. The objective was poking through a 30mm diameter hole, and this dome was heavily painted flat white inside & out
What I hope to develop is a system where the dome light (painted only on the inside) is first used as a working light (for orienting & focusing the subject), then shut off and used as a diffuser -- for a flash unit(s) outside the dome. Preliminary work shows this concept to be very promising; I need to experiment further on how much spray paint (flat white enamel) to use on the inside of the dome, etc. The beauty of using the plastic water bottles as dome material is that they are very cheap and easily fabricated -- so many copies can be made & tested.
Eric
My comment on suitability for the dome light at over 5:1 mag should be explained further. I think these lights are useful at even higher mags than these but that flash will probably offer the highest resolution & detail (based on the many excellent images on this forum -- not on my own work; I'm just starting in this area...). I've included one image (single shot) of a butterfly wing taken with just the illumination of a 144 LED dome ring-light, using a Leitz 20x/.33 UM with a Leitz 6.3x Periplan eyepiece. This objective has about 14mm working distance, however the light will work down to as close as about 5mm. The objective was poking through a 30mm diameter hole, and this dome was heavily painted flat white inside & out
What I hope to develop is a system where the dome light (painted only on the inside) is first used as a working light (for orienting & focusing the subject), then shut off and used as a diffuser -- for a flash unit(s) outside the dome. Preliminary work shows this concept to be very promising; I need to experiment further on how much spray paint (flat white enamel) to use on the inside of the dome, etc. The beauty of using the plastic water bottles as dome material is that they are very cheap and easily fabricated -- so many copies can be made & tested.
Eric
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rjlittlefield
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Eric, thanks for the detailed information and analysis regarding the LED ring light. Very helpful!
Regarding the glitch with your image upload, I checked the forum files. It looks like your image itself did upload correctly the first time, but for some reason the corresponding [img] tag did not get injected into your post. This is not unusual for new users -- it happened to me the first few times too. But it seems you have it sorted out now, so probably it'll work fine from here on. If you run into further difficulties, drop me a note and I'll see if I can figure out what the snag is.
--Rik
Regarding the glitch with your image upload, I checked the forum files. It looks like your image itself did upload correctly the first time, but for some reason the corresponding [img] tag did not get injected into your post. This is not unusual for new users -- it happened to me the first few times too. But it seems you have it sorted out now, so probably it'll work fine from here on. If you run into further difficulties, drop me a note and I'll see if I can figure out what the snag is.
--Rik
Re: LED's
Plastic milk cartons make good diffuser material and would eliminate the painting step. Alternatively, Tap plastics (or other plastic retailer) has lots of thin sheets in a variety of colors and opacity (and inexpensive).Eric F wrote: and this dome was heavily painted flat white inside & out
What I hope to develop is a system where the dome light (painted only on the inside) is first used as a working light (for orienting & focusing the subject), then shut off and used as a diffuser -- for a flash unit(s) outside the dome. Preliminary work shows this concept to be very promising; I need to experiment further on how much spray paint (flat white enamel) to use on the inside of the dome, etc. The beauty of using the plastic water bottles as dome material is that they are very cheap and easily fabricated -- so many copies can be made & tested.
Eric
Are you forming the dome with just heat or using a vacuum as well?
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augusthouse
- Posts: 1195
- Joined: Sat Sep 16, 2006 1:39 am
- Location: New South Wales Australia
EricF wrote:
There are a couple of members (myself included) that I am aware of who have been looking closely at the range available from Rosco: Roscolux, Supergel, E-Colour and Cinegal. The gels can be purchased in sheets and may also be used (are used) on speedlights. Free swatchbooks are available. The range of diffuser material is - superb. Colour/light temp. manipulation is also another available feature when using such gels.
http://www.rosco.com/us/products/lighting.asp
Craig
Eric, another suggestion also worth considering is the use of gels. These can be 'swapped-out' according to specific image requirements. There is an extensive range of diffusers and gel material available.I need to experiment further on how much spray paint (flat white enamel) to use on the inside of the dome
There are a couple of members (myself included) that I am aware of who have been looking closely at the range available from Rosco: Roscolux, Supergel, E-Colour and Cinegal. The gels can be purchased in sheets and may also be used (are used) on speedlights. Free swatchbooks are available. The range of diffuser material is - superb. Colour/light temp. manipulation is also another available feature when using such gels.
http://www.rosco.com/us/products/lighting.asp
Craig
Last edited by augusthouse on Sat Feb 21, 2009 2:47 pm, edited 1 time in total.
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"
LED's
Thanks Rik,
Main problem was I didn't see the bottom part of the 'send' dialog box the first time!
Elf,
The dome is largely preformed -- as shown on the website mentioned in my first post. My goal is to make it both reflective on the inside, and diffuser-like from the outside.
Eric
Main problem was I didn't see the bottom part of the 'send' dialog box the first time!
Elf,
The dome is largely preformed -- as shown on the website mentioned in my first post. My goal is to make it both reflective on the inside, and diffuser-like from the outside.
Eric
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augusthouse
- Posts: 1195
- Joined: Sat Sep 16, 2006 1:39 am
- Location: New South Wales Australia
Just to further explain the suggestion for considering the Rosco gels. Here is a link to an image of some diffuser cylinders.
http://www.visionarydigital.com/diffusers.html
Craig
http://www.visionarydigital.com/diffusers.html
Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"
LED's
Craig,
Yes, I've seen their website; neat stuff! Do you think these diffuser cylinders have gel coatings on the inside?
Elf,
Thanks, Eric
Yes, I've seen their website; neat stuff! Do you think these diffuser cylinders have gel coatings on the inside?
Elf,
This would be a very good thing, for sure. Do you have a good reference on how to do this (especially for someone without any special fabrication equipment...)?more control over the shape of the dome and how the light was reflected inside the dome
Thanks, Eric
It's been a couple of years since I saw a demo of this at a wood turning club meeting. It doesn't take any specialized equipment. The vacuum doesn't need to be very strong. A home vacuum cleaner will work.
The plastic is placed over the open end of a cylinder, vacuum is pulled, and heat applied.
I don't remember if a hair dryer or a small propane torch was used for the heat source.
Making the dome like this will allow moving the oculus to one side and with the addition of flocking from http://www.protostar.biz/flock.htm you would have a very flexible system. The flocking could be placed on another dome that just fits inside the reflector dome and then could be repositioned easily.
The plastic is placed over the open end of a cylinder, vacuum is pulled, and heat applied.
I don't remember if a hair dryer or a small propane torch was used for the heat source.
Making the dome like this will allow moving the oculus to one side and with the addition of flocking from http://www.protostar.biz/flock.htm you would have a very flexible system. The flocking could be placed on another dome that just fits inside the reflector dome and then could be repositioned easily.
LED's
Thanks Elf,
I'll have to try do some vacuum forming when I get the chance; sounds like it could open up a lot of options (also sounds like it would take a bit of practice to get it right!).
I'm not certain I understand the advantage of moving the oculus off center -- at least for our needs. The flocking ("black hole") material would be excellent for light control. However, other domes now available (but not we first did our work) have light control in each of four zones -- which seems the best way to control interior light dispersion.
Eric
I'll have to try do some vacuum forming when I get the chance; sounds like it could open up a lot of options (also sounds like it would take a bit of practice to get it right!).
I'm not certain I understand the advantage of moving the oculus off center -- at least for our needs. The flocking ("black hole") material would be excellent for light control. However, other domes now available (but not we first did our work) have light control in each of four zones -- which seems the best way to control interior light dispersion.
Eric