Forum Discussion
IMPORTANT - Improve Image Quality With IPD Adjusters
One of the biggest and most overlooked problems I have encountered with the developer kit is it's complete lack of Interpupillary distance (IPD) adjustments.
This has been mentioned a couple times in the past, however I have been blown away by the number of dev kit users who simply ignore or don't understand how big of a difference properly spaced lenses can make to improve picture quality, sharpness and clarity. If you know what your IPD is and it's within 62mm - 66mm respectively you should be close enough to the dev kits default 64mm value and realize only partial benefits from adjusters. However if your IPD is 61mm and below or 67mm or greater, or if you don't know what your actual IPD value is, it's important that you continue reading.
I cannot overstate how much of an improvement adjusters can make in the end. Depending on how high or low your IPD range is, I estimate adjusters provide a 15%-55% improvement in picture quality plus you get the comfort and convenience of having the sweet spot centered to your specific IPD which allows more room for shifting, movement and not having to re-adjust the dev kit every couple minutes. It's like having a custom tailored headset fitted to your exact measurements straight from a VR lab.
As we know, the developer kits suffer from larger pixel densities and lower resolution displays which results in a compromised final image. As such, it's essential other issues which may impede user vision be corrected as this is effectively the next step to improve image quality outside elements we have no control over.
When I first received my dev kit and started using it, one of the first things I realized was how frustrating it was for me to find and maintain that sweet spot necessary for a clearer picture. It's important to note that adjusting the dev kit up and down isn't a problem as anyone can simply adjust the head-strap accordingly for a proper vertical center. The real issue is once you try improving the picture by moving the lenses side to side.
In my experience, most people with IPD's outside the range of 61mm and 67mm don't realize they can improve picture quality in the side to side range substantially with the use of now available IPD adjusters specifically made for the dev kit's which can be found here: http://www.shapeways.com/shops/vrgear
Attached is a picture showing how the adjusters install and how they correct lens distance:
JCmIDMk.gif
The IPD adjusters allow the user to decrease or increase the lens separation to a level that is custom tailored to their specific IPD, thus correcting blurriness as a result of improper pupil to lens centers. The more your IPD is off from the default 64mm, the more blurry and worse the picture quality becomes. One of the easiest ways to test and determine if you have this problem is while wearing the dev kit simply close one eye and move it side to side until the image is as clear as possible, then without moving the dev kit switch to the other eye. If the other eye is blurry or you can't seem to center both eyes for the clearest image possible then your IPD is likely too far outside the range of the dev kits default values. During extensive testing I determined that anyone with IPD's outside of 61mm and lower or 67mm and higher should install IPD adjusters right away.
IPD Adjuster.jpg
As an optician who previously managed a vision clinic I encountered this problem frequently with day to day corrective eyewear in patients. Additionally, since my IPD is also outside the values outlined above (59.5mm) I too suffered from this problem as I couldn't seem to get both eyes centered as well.
I immediately set out to try and find a method to correct the problem, initially the only fix I could find involved a very questionable procedure involving foam, tape, hot gluing and even modding the lens cups which wasn't feasible in my mind. Many months after the release of the dev kit, a friend sent me a link to these: http://www.shapeways.com/designer/VR_Gear
I immediately ordered a pair. Inspected, installed and thoroughly tested them and was extremely satisfied with the results. I was initially concerned that installing them may correct my initial IPD issue but alter the picture as a result as IPD adjustments technically need to be altered on the software end as well to match the new lens center. I'm happy to report that the adjusters didn't make any notable change in picture quality at all. I fully confirmed this as I swapped between the original spacing and the new spacing many times to test my findings.
To find out what your IPD is, there are three easy methods to do this:
#1 - Use the Oculus calibration tool included in the SDK (retry the test a couple time to confirm your IPD)
#2 - Use a veneer caliper or similar measuring tool, while holding it in the mirror line up the center of each pupil (closing each eye) back and forth adjust the caliper to obtain your correct IPD. Then subtract half a mm (0.5mm) afterwards for convergence)
#3 - Go to a local eye doctor and ask them to take your IPD reading (they usually charge around $20 for this service)
It's important to note that simply ordering the IPD adjusters matched to your specific IPD isn't likely the best scenario in most cases since you want to try and divide your IPD difference between the software IPD (64mm) to try and balance out your visual improvement vs distortion. Even though I experienced no distortion in my case (I purchased the 62mm adjusters) it's important to note that everyone has a different IPD and depending how far you go from the default 64mm range, you may encounter picture distortion or loss of FOV. This is why I suggest balancing out these two aspects.
Below is a guide I designed after extensive testing which I found to offer the best results with IPD's 61mm and below:
(Due To Printer Tolerances, Finishing And Designer Revisions Use This Guide At Your Own Risk)
Users with an IPD of 59.5mm - 61mm should get the 62mm adjusters
Users with an IPD of 58.5mm - 59.4mm should get the 61mm adjusters
Users with an IPD of 58.4mm or lower should get the 60mm adjusters
Note: Depending on how far you turn the adjusters during installation, they offer about .75mm of play in each direction, for a total variation of 1.50mm back and forth. This excludes the 60mm adjusters because the lens cups physically touch each other in this case
Since I was only able to test for IPD values on the lower scale, users with IPD values 67mm and above can estimate what appropriate adjusters are required or they can contact the designer here: http://www.shapeways.com/forum/index.php?t=ppost&toi=408697&back_to_model=http://www.shapeways.com/model/1316565/60mm-lens-ipd-adjuster-oculus-rift-dk.html?li=send_message
One important aspect during installation is to ensure the eye area of the dev kit is clean and free of dust and hair prior to removing the lenses for adjuster installation. I strongly recommend running the OculusLCDScreenCleaner utility prior to removing the lenses to mark where the small dust spots are located on the screen. While you have the lenses removed use the included Oculus lens cleaning cloth to gently lift those specific particles off. You may have to repeat this procedure a couple times to remove all the black dust particles from the screen. Afterwards install the adjusters with "C" lenses on top of the adjusters in place of the "A" lenses.
Adjusters_Installed.jpg
Other important points worth mentioning. Any developers who normally use "C" or "B" lenses and intend to use the IPD adjusters as well must use contact lenses or their glasses afterwards to correct for nearsightedness as the shorter "C" lenses are required for use with the adjusters to obtain the same height the "A" lenses normally set at. Developers who intend to show off their dev kits should remove the adjusters as they will make the screen blurry for users with normal IPD's. Also, it's important to never use the Oculus calibration tool after the adjusters are installed as you will get incorrect results with them in place. This includes any other IPD calibration software including Valves TF2 calibration tool, so use those tools prior to installing the adjusters. Finally, combining the adjusters with an upscaled resolution from 1920x1200 or 1080p makes a huge improvement in picture quality over the native 1280x800. Try and run a minimum of 1080p at all times.
Anyone who installs these adjusters please post your results below for others to see and I wanted to give a big shout out to the designer of such an amazing product, these truly feel like an official Oculus accessory. Shapeways uses powder based 3D printers so the quality is superior to extruder based counterparts, thanks.
This has been mentioned a couple times in the past, however I have been blown away by the number of dev kit users who simply ignore or don't understand how big of a difference properly spaced lenses can make to improve picture quality, sharpness and clarity. If you know what your IPD is and it's within 62mm - 66mm respectively you should be close enough to the dev kits default 64mm value and realize only partial benefits from adjusters. However if your IPD is 61mm and below or 67mm or greater, or if you don't know what your actual IPD value is, it's important that you continue reading.
I cannot overstate how much of an improvement adjusters can make in the end. Depending on how high or low your IPD range is, I estimate adjusters provide a 15%-55% improvement in picture quality plus you get the comfort and convenience of having the sweet spot centered to your specific IPD which allows more room for shifting, movement and not having to re-adjust the dev kit every couple minutes. It's like having a custom tailored headset fitted to your exact measurements straight from a VR lab.
As we know, the developer kits suffer from larger pixel densities and lower resolution displays which results in a compromised final image. As such, it's essential other issues which may impede user vision be corrected as this is effectively the next step to improve image quality outside elements we have no control over.
When I first received my dev kit and started using it, one of the first things I realized was how frustrating it was for me to find and maintain that sweet spot necessary for a clearer picture. It's important to note that adjusting the dev kit up and down isn't a problem as anyone can simply adjust the head-strap accordingly for a proper vertical center. The real issue is once you try improving the picture by moving the lenses side to side.
In my experience, most people with IPD's outside the range of 61mm and 67mm don't realize they can improve picture quality in the side to side range substantially with the use of now available IPD adjusters specifically made for the dev kit's which can be found here: http://www.shapeways.com/shops/vrgear
Attached is a picture showing how the adjusters install and how they correct lens distance:
JCmIDMk.gif
The IPD adjusters allow the user to decrease or increase the lens separation to a level that is custom tailored to their specific IPD, thus correcting blurriness as a result of improper pupil to lens centers. The more your IPD is off from the default 64mm, the more blurry and worse the picture quality becomes. One of the easiest ways to test and determine if you have this problem is while wearing the dev kit simply close one eye and move it side to side until the image is as clear as possible, then without moving the dev kit switch to the other eye. If the other eye is blurry or you can't seem to center both eyes for the clearest image possible then your IPD is likely too far outside the range of the dev kits default values. During extensive testing I determined that anyone with IPD's outside of 61mm and lower or 67mm and higher should install IPD adjusters right away.
IPD Adjuster.jpg
As an optician who previously managed a vision clinic I encountered this problem frequently with day to day corrective eyewear in patients. Additionally, since my IPD is also outside the values outlined above (59.5mm) I too suffered from this problem as I couldn't seem to get both eyes centered as well.
I immediately set out to try and find a method to correct the problem, initially the only fix I could find involved a very questionable procedure involving foam, tape, hot gluing and even modding the lens cups which wasn't feasible in my mind. Many months after the release of the dev kit, a friend sent me a link to these: http://www.shapeways.com/designer/VR_Gear
I immediately ordered a pair. Inspected, installed and thoroughly tested them and was extremely satisfied with the results. I was initially concerned that installing them may correct my initial IPD issue but alter the picture as a result as IPD adjustments technically need to be altered on the software end as well to match the new lens center. I'm happy to report that the adjusters didn't make any notable change in picture quality at all. I fully confirmed this as I swapped between the original spacing and the new spacing many times to test my findings.
To find out what your IPD is, there are three easy methods to do this:
#1 - Use the Oculus calibration tool included in the SDK (retry the test a couple time to confirm your IPD)
#2 - Use a veneer caliper or similar measuring tool, while holding it in the mirror line up the center of each pupil (closing each eye) back and forth adjust the caliper to obtain your correct IPD. Then subtract half a mm (0.5mm) afterwards for convergence)
#3 - Go to a local eye doctor and ask them to take your IPD reading (they usually charge around $20 for this service)
It's important to note that simply ordering the IPD adjusters matched to your specific IPD isn't likely the best scenario in most cases since you want to try and divide your IPD difference between the software IPD (64mm) to try and balance out your visual improvement vs distortion. Even though I experienced no distortion in my case (I purchased the 62mm adjusters) it's important to note that everyone has a different IPD and depending how far you go from the default 64mm range, you may encounter picture distortion or loss of FOV. This is why I suggest balancing out these two aspects.
Below is a guide I designed after extensive testing which I found to offer the best results with IPD's 61mm and below:
(Due To Printer Tolerances, Finishing And Designer Revisions Use This Guide At Your Own Risk)
Users with an IPD of 59.5mm - 61mm should get the 62mm adjusters
Users with an IPD of 58.5mm - 59.4mm should get the 61mm adjusters
Users with an IPD of 58.4mm or lower should get the 60mm adjusters
Note: Depending on how far you turn the adjusters during installation, they offer about .75mm of play in each direction, for a total variation of 1.50mm back and forth. This excludes the 60mm adjusters because the lens cups physically touch each other in this case
Since I was only able to test for IPD values on the lower scale, users with IPD values 67mm and above can estimate what appropriate adjusters are required or they can contact the designer here: http://www.shapeways.com/forum/index.php?t=ppost&toi=408697&back_to_model=http://www.shapeways.com/model/1316565/60mm-lens-ipd-adjuster-oculus-rift-dk.html?li=send_message
One important aspect during installation is to ensure the eye area of the dev kit is clean and free of dust and hair prior to removing the lenses for adjuster installation. I strongly recommend running the OculusLCDScreenCleaner utility prior to removing the lenses to mark where the small dust spots are located on the screen. While you have the lenses removed use the included Oculus lens cleaning cloth to gently lift those specific particles off. You may have to repeat this procedure a couple times to remove all the black dust particles from the screen. Afterwards install the adjusters with "C" lenses on top of the adjusters in place of the "A" lenses.
Adjusters_Installed.jpg
Other important points worth mentioning. Any developers who normally use "C" or "B" lenses and intend to use the IPD adjusters as well must use contact lenses or their glasses afterwards to correct for nearsightedness as the shorter "C" lenses are required for use with the adjusters to obtain the same height the "A" lenses normally set at. Developers who intend to show off their dev kits should remove the adjusters as they will make the screen blurry for users with normal IPD's. Also, it's important to never use the Oculus calibration tool after the adjusters are installed as you will get incorrect results with them in place. This includes any other IPD calibration software including Valves TF2 calibration tool, so use those tools prior to installing the adjusters. Finally, combining the adjusters with an upscaled resolution from 1920x1200 or 1080p makes a huge improvement in picture quality over the native 1280x800. Try and run a minimum of 1080p at all times.
Anyone who installs these adjusters please post your results below for others to see and I wanted to give a big shout out to the designer of such an amazing product, these truly feel like an official Oculus accessory. Shapeways uses powder based 3D printers so the quality is superior to extruder based counterparts, thanks.
23 Replies
- That's a great idea and the design looks good.
My ipd is only 58 mm and I find both eyes are never quite in the sweet spot at the same time - I've learned to live with slight blurriness. I did try to do my own narrow ipd mod using the spare c-cups as described in an older thread, but I found the distortion it introduced was worse than the blurriness (perhaps my engineering wasn't precise enough, I don't know). One thing was for sure though, it was a hell of a lot more comfortable to wear with the lenses actually aligned with my eyes for a change.
Anyway, for $20 I will definitely give it another shot. Ordering the 60 mm ones now... I will post up my impression afterwards. - Interesting. I may have to try these out. My IPD is 68.5 and it's sometimes difficult to find the "sweet spot" w/ DK1.
- Just beware.
Moving the lenses has the consequence of moving the lens center away from the stereo projection center. Normally when you look straight through the lens you are looking at the middle pixel in the 3D scene. That's true even if you aren't looking through the center of the lens - such as when your IPD does not match the lens separation. Because the light is collimated, the "center pixel" (which happens to also be the stereo projection center) will follow your eye around as long as you are looking straight. You may be looking through a little right or left of lens center, but you are still staring at the center pixel - and thus the stereo images will converge easily. The side of the lenses may be more blurry and warpy but they transmit that center pixel straight through.
However, once you move the lenses a different "center pixel" will follow your eye around - one that is not the stereo projection center. So in order to stereo converge, you will be forced to converge or diverge your eyes away from parallel to focus back at the real stereo center. You will probably be able to do this, but it could lead to strain and discomfort over long periods of time and the more extreme the offset the more straining it will be.
If you have an old Oculus SDK 1.0 laying around (no longer on the website) you can test just how uncomfortable this can get. In the original release we mistakenly adjusted the center of projection to match the user IPD. In the old Tuscany you could adjust the IPD and projection center far enough until you could no longer stereo converge. - I did not notice any negative change or alteration to the rendered scene, only an improvement in picture quality. Most people who use these will realize an instant improvement with no change in screen characteristics unless they need to order the adjusters at the extreme low or high end of the range.
60mm users will notice a slight reduction in the outer FOV however the benefits are unquestionably improved.
68mm users or greater will notice a change in scale, however the improvements still outweigh the cons."cybereality" wrote:
Interesting. I may have to try these out. My IPD is 68.5 and it's sometimes difficult to find the "sweet spot" w/ DK1.
Cyber, with an IPD like yours I'm very surprised you aren't using these yet. At 68.5 you will notice a substantial improvement with them. I would go with the 66mm or 67mm adjusters. All VR headsets are supposed to provide manual IPD adjustments although Oculus decided to leave this feature out on the dev kits. It truly is a required component developers need correct for right away.
That said, please sticky this thread so we can let as many people know about this. - Once I installed the adjusters, the first demo I tested them on was Titans Of Space and the improvement was mind blowing. The text is vastly clearer and much easier to read. The textures are much more defined on the planets and I didn't have to keep adjusting the rift to try and center the lenses every minute.
Don't take my word for it, try them out and report your results. - I just received the 60 mm ones today (my IPD is 58). I got the flat black ones. They are well made, have a nice finish and fit the lenses and oculus perfectly. I tested them out using the Redframe demo, which I am very accustomed to.
I hate to say it, but I didn't like them. Although the image is better focused, they made my eyes feel a little wonky - similar to if I use vrplayer and the horizontal offset isn't set quite right. I was also able to detect the edge of the ring where the circle is flattened at the inner attachment point. I didn't notice any reduction in the field of view at the periphery though, so that was good. Another problem for me was that the closer lens separation caused the lens cups to press against the bridge of my nose. I tried turning the rings so I could move the lenses apart a little (the 60 mm size isn't really adjustable). This seemed to help visually and it was more comfortable on the nose, but didn't quite fix it. Perhaps the 61 or 62 mm rings would have been a better compromise for me. Oh well. :| - Great write up Post by OculusOptician. Do you have any insight for DK2 now that it has been announced?
"grodenglaive" wrote:
Although the image is better focused, they made my eyes feel a little wonky - similar to if I use vrplayer and the horizontal offset isn't set quite right.
Sounds like they are working properly but your settings are wrong. Make sure you have the "C" lenses installed and try the newest version of Titans Of Space as it features the newest SDK to work along side the Oculus Configuration IPD presets. Most demo's (especially the older ones) run off the old SDK's which don't communicate with the Config Tool settings. Ensure your correct IPD settings are selected in the Oculus Configuration tool. Note that you cannot use the calibration tool after you install the adjusters because it throws off the results so either enter in your correct IPD or take out the adjusters, calibrate with the "A" lenses and put the adjusters back in after you calibrate.
Also make sure you are running a 16:10 ratio resolution as other resolutions can cause the problems your describing as well.
Another thing you can do is boot up the latest version of Half-Life 2 or Half-Life 2VR in steam, open the console and type:
"vr_separation_hmd_inches = 2.3622" (that is 60mm in inches)
This changes the software to show exactly 60mm spacing to match your 60mm adjusters, should work like a charm."VRMatthew" wrote:
Great write up Post by OculusOptician. Do you have any insight for DK2 now that it has been announced?
Hey Matt,
The DK2 features larger lenses which provide more of a sweet-spot area, so less users will experience IPD related issues with this model. However, the DK2 still won't support any form of IPD adjustment so hopefully VR-Gear will design new adjusters as some users with extremely narrow and wide IPD's will still experience issues without them.
From what I understand, all previous demos are not compatible with the DK2 as crucial dimensions have changed. This isn't that big of an issue however as it simply requires the developer to go in and update their game to reflect this. This is a one time requirement as Oculus announced any future DK2 content (or DK1 converted to DK2 content) will be fully compatible with the consumer model when it's released.- Great post! I hadn't seen this up until now as I was search for some older ones. I'm the guy behind the VR-Gear adjusters.
I was really hoping (and still am) that the adjusters would be made obsolete by the new optics but I just saw a post that claims they get a bad view at a 61mm IPD which is worrisome. I've asked them to confirm that IPD because it doesn't sound right as it isn't that extreme.
Post is here, issue #2
http://www.reddit.com/r/oculus/comments/2bqtyj/my_1st_day_with_the_dk2_concerns_and_comments/
When I get my DK2, I'll see how it is for me and also keep a look out to see how it is for everyone. What is frustrating is that this approach of adjustment would work really well if Oculus provided some means of overriding the distortion position variable... it's like a ramp for people in wheelchairs with a step right at the end that is on Oculus' territory. - Bwhill,
I wanted to thank-you personally for making these IPD adjusters and being on top of this from day one. It frustrates me that Oculus isn't providing a factory solution to this serious problem. Almost every headset manufacturer has allowed for IPD adjustments in the past as far back as the Forte VFX-1 days and even developer products such as the Durovis Dive.
Not only does this lack of IPD adjustments impede the visual experience for many users, it's also stressful on our eyes and can cause frequent headaches as well. It's important to note we're not talking about everyday consumers here but rather industry leading software developers who spend countless hours each day trying to deal with compromised visual fidelity, some of them aren't even aware it can be improved either as was the case with a friend of mine (an IPD of 58mm).
I can't understand why Oculus would now include a health and safety disclaimer as part of the new DK2 SDK for "developers" but have completely neglected to address this huge problem on the hardware end.
The DK2 features larger lenses and Oculus in fact even published that the IPD sweet spot had been increased as a result but according to this recent review the problem still exists and hasn't been corrected. Most of my friends including myself have IPD's which are to narrow for the dev kits, some are as follows: 58mm, 59.6mm and 61mm respectively but we can't forget those have too high IPD's also.
Your adjusters completely solved the problem I was having with my DK1, not sure if they will actually swap right over to the DK2 but since Oculus has changed the actual cups and doesn't include a C set now, that's doubtful. As soon as you receive your DK2 please update us on your findings, as will I.
