Coolhand78 Posted September 2, 2014 Share Posted September 2, 2014 I'm finding that whenever I use VRay IES light and using almost any IES files be evermotion or GE i have to set the power value to huge numbers in order to get any sort of natural looking light... using max 2014 vray2.4, lwf etc... anyone else here have the same issue or am i doing something wrong..? Link to comment Share on other sites More sharing options...
jasonstewart Posted September 2, 2014 Share Posted September 2, 2014 Well if you turn the lights on during the day they are not as noticeable vs. evening or night. Your sun/sky or HDRI could be overpowered as well. What kind of camera settings are you using? Can you post a quick render of your scene just to see what you have going on? Link to comment Share on other sites More sharing options...
Coolhand78 Posted September 2, 2014 Author Share Posted September 2, 2014 Well if you turn the lights on during the day they are not as noticeable vs. evening or night. Your sun/sky or HDRI could be overpowered as well. What kind of camera settings are you using? Can you post a quick render of your scene just to see what you have going on? Hey mate, It's not one particular scene, it's just something that i've noticed when trying to use them both in interior scenes as well as using them for internal illumination for dusky exterior shots... I normally use a dome light with a HDRI map, and camera settings are dependant on the scene, but mostly i try to adhere to Peter Guthries suggested settings for the dome and HDRI, multiplier at 1 for both... sometimes i'll drop the HDRI multiplier if its too much or if i feel the appature is set too low for that particular lighting... I don't use reinhard though as he does, i stick with linear multiply for colour mapping... Link to comment Share on other sites More sharing options...
jasonstewart Posted September 2, 2014 Share Posted September 2, 2014 I don't disagree with you. Its just hard to blame the IES when you could just as easily blame the HDRI/Dome and say it is too bright. If you are using a few different IES profiles from a manufacture for example and notice that they all seem too dark then maybe your HDRI/Dome needs to be a little darker. I am interested to see what others have to say. Link to comment Share on other sites More sharing options...
Ismael Posted September 2, 2014 Share Posted September 2, 2014 I am interested to see what others have to say. I say the same as you. Link to comment Share on other sites More sharing options...
Chris MacDonald Posted September 2, 2014 Share Posted September 2, 2014 As a rule of thumb I use lumens for my interior lights so that I can set them to between 1200 to 1800, in the knowledge that this is what a typical 100W incandescent bulb would emit. I sometimes will change the colour temperature to a warm white too, around 4500K. This then gives me a real world starting point. Then I'll set my camera exposure to correctly expose the interior, and tweak the HDRI multiplier to suit the image. Obviously if you're indoors on a bright day, the windows are going to be blown out; especially if they are small windows. What are you doing with your IES lights? Got a screenshot? Link to comment Share on other sites More sharing options...
rjohnson33 Posted September 2, 2014 Share Posted September 2, 2014 Why not do a small test with a Vray Physical Camera set up for a typical real world interior using a photographic exposure chart and then see what power you have to use in your IES lights to get anything close to a decent exposure? I'd say you're better off working backwards from realistic camera settings if you are concerned for some reason about going for real world power values in lights - as opposed to say working from an HDRI in a dome light because I tend to find the values of these vary too wildly. Having said that, there's not necessarily much point in doing all of this. In most scenarios just set lighting so that it appears correct and if you end up with crazy values in your camera exposure what does it matter? I know I've entered huge values into the power of IES lights before. I'm sure these are set ups where I've been led by an HDRI in a dome as the principle lighting and then come to introduce the IES at a later stage. Link to comment Share on other sites More sharing options...
Ismael Posted September 3, 2014 Share Posted September 3, 2014 As a rule of thumb I use lumens for my interior lights so that I can set them to between 1200 to 1800, in the knowledge that this is what a typical 100W incandescent bulb would emit. I sometimes will change the colour temperature to a warm white too, around 4500K. This then gives me a real world starting point. Then I'll set my camera exposure to correctly expose the interior, and tweak the HDRI multiplier to suit the image. Obviously if you're indoors on a bright day, the windows are going to be blown out; especially if they are small windows. What are you doing with your IES lights? Got a screenshot? Excellent workflow.Dialux Room.pdf Link to comment Share on other sites More sharing options...
Chris MacDonald Posted September 3, 2014 Share Posted September 3, 2014 as opposed to say working from an HDRI in a dome light because I tend to find the values of these vary too wildly. Totally. It depends what the white point is set at on the HDRI really, as it's floating point; but it's not entirely dissimilar from what you experience in the real world in that respect - One day might be bright and sunny, another might be dull and overcast; the only thing that is guaranteed to stay the same is interior lighting. Expose for the interior, then bring up/down the HDRI multiplier to suit the image, and always keep photographic references to hand. Link to comment Share on other sites More sharing options...
Coolhand78 Posted September 3, 2014 Author Share Posted September 3, 2014 Why not do a small test with a Vray Physical Camera set up for a typical real world interior using a photographic exposure chart and then see what power you have to use in your IES lights to get anything close to a decent exposure? I'd say you're better off working backwards from realistic camera settings if you are concerned for some reason about going for real world power values in lights - as opposed to say working from an HDRI in a dome light because I tend to find the values of these vary too wildly. Having said that, there's not necessarily much point in doing all of this. In most scenarios just set lighting so that it appears correct and if you end up with crazy values in your camera exposure what does it matter? I know I've entered huge values into the power of IES lights before. I'm sure these are set ups where I've been led by an HDRI in a dome as the principle lighting and then come to introduce the IES at a later stage. I'm going to give this a go... thanks for the advice...! Link to comment Share on other sites More sharing options...
Stephen Thomas Posted September 4, 2014 Share Posted September 4, 2014 The majority, if not all of the IES files you download from manufacturers will have correct output value. It's not just about light shape after all, and you should base your camera exposure on these. HDRIs on the other hand are completely arbitrary and while there may be correlation between HDRIs from the same source, they can vary wildly and exposure value is always an artistic choice. Link to comment Share on other sites More sharing options...
elipan Posted September 5, 2014 Share Posted September 5, 2014 Read this: http://www.workshop.mintviz.com/tutorials/vray-real-world-light-intensity/ I set up my scenes with Luminous Power and just simply calculate: 100W (tungsten bulb) X 17.5 luminous (per watt) = 1750 Luminous Power value. Because this is set up in meters by default and I work in centimeters environment, I need to square it (10cm x 10cm= 100) So, 1750 X (10x10) = 175000 Luminous Power value for a single 100W tungsten bulb in Vray light. At it looks beautiful in most setups. Just try to setup accurately the temperture. Link to comment Share on other sites More sharing options...
Coolhand78 Posted September 5, 2014 Author Share Posted September 5, 2014 Read this: I set up my scenes with Luminous Power and just simply calculate: 100W (tungsten bulb) X 17.5 luminous (per watt) = 1750 Luminous Power value. Because this is set up in meters by default and I work in centimeters environment, I need to square it (10cm x 10cm= 100) So, 1750 X (10x10) = 175000 Luminous Power value for a single 100W tungsten bulb in Vray light. At it looks beautiful in most setups. Just try to setup accurately the temperture. this is great! thanks for this, i'm gonna try this - will report back!! Link to comment Share on other sites More sharing options...
inpow watir Posted September 7, 2014 Share Posted September 7, 2014 Looking forward to see the report :-) Link to comment Share on other sites More sharing options...
elavenild Posted May 2, 2015 Share Posted May 2, 2015 hi guys i'm using 3ds max 2013 vray 2.40.My ies lights are too dark.how to increase the brightness of the light.please help me..!! Link to comment Share on other sites More sharing options...
Coolhand78 Posted May 2, 2015 Author Share Posted May 2, 2015 hi guys i'm using 3ds max 2013 vray 2.40.My ies lights are too dark.how to increase the brightness of the light.please help me..!! Can u post some settings? You probably just need to increase the power? Link to comment Share on other sites More sharing options...
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