DJI focus problem

[DocPat]

For everyone having problems with the focus of their DJI Goggles it is worthwhile noting the following facts: It turns out that the lens power of the Goggles Is 10 diopters. The distance from the lens to the LCD screen is approximately 7.5 cm. A simple calculation shows that a person with normal vision will see the DGI Goggles screen at a virtual distance of only 30cm.

The problem is that for most people this is much too close for comfort. Most people will want to view a real screen (PC, TV etc) at a much greater distance than this, usually at least a meter or so, particularly if they want to raise the goggles to view their drone without having to adjust focus by removing glasses etc. or watch movies through the goggles with the same comfort as watching a TV or theatre screen.

The strength of the DJI Goggles lens required to achieve a virtual distance to the screen of 1 meter can easily be calculated. The calculation gives a revised lens power of 12.33 diopters for the DJI Goggles lenses.

This means that an INCREASE in lens power is required by the DJI Goggles of AT LEAST 2.33 diopters. This is in complete agreement with what has been found by many other users by trial and error.

This is obviously a design fault and oversight on behalf of DJI and I would suggest that all owners of the DJI Goggles contact DJI or the supplier of this product and ask for a free replacement and refit of the lenses with a more acceptable power of 12.5 diopters.

 

[DocPat]

For many people the preferred virtual distance to the screen whilst the drone is in flight is INFINITY, as this is where the eye would be focused from the camera perspective. In this case the calculation gives a revised lens power of 13.33 diopters, an increase of 3.33 diopters!

 

[zezrum]

I recently acquired the DJI Goggles RE. I wear Rx reading glasses. I don't need them for anything other than reading/computer. With the DJI Goggles RE, if I don't use my glasses the image is completely blurry, but with my reading glasses the image is nearly perfect. I was pleased to discover that the goggles fit fine over my glasses.

When I first tried to fit the goggles, I was trying to seal them to my face and block out all of the external light, much like I would when using VR glasses. It wasn't comfortable that way and parts of the screen were obscured. Then I tried a new approach. I adjusted the headband so the goggles float over my eyes. It's not a perfect seal, but doing such they became quite comfortable to wear and I can view the entire screen with ease. I recommend anyone having fit issues to re-think their approach and go for a lose fit, as that is what solved the fit issues for me.

I'm glad that the goggles fit fine over my reading glasses. I passed them around a group of us flying today and a few others also had glasses and those that did said that the goggles felt fine and they could clearly see the screen. That's good news. But I don't want to fly with my reading glasses on, since when I raise the goggles I need to remove my glasses in order to see far away! So I ordered the DJI focus inserts and hope those will have the same effect as my reading glasses.

Thanks for sharing the technical details above.

 

[DocPat]

I recently acquired the DJI Goggles RE. I wear Rx reading glasses. I don't need them for anything other than reading/computer. With the DJI Goggles RE, if I don't use my glasses the image is completely blurry, but with my reading glasses the image is nearly perfect. I was pleased to discover that the goggles fit fine over my glasses.

When I first tried to fit the goggles, I was trying to seal them to my face and block out all of the external light, much like I would when using VR glasses. It wasn't comfortable that way and parts of the screen were obscured. Then I tried a new approach. I adjusted the headband so the goggles float over my eyes. It's not a perfect seal, but doing such they became quite comfortable to wear and I can view the entire screen with ease. I recommend anyone having fit issues to re-think their approach and go for a lose fit, as that is what solved the fit issues for me.

I'm glad that the goggles fit fine over my reading glasses. I passed them around a group of us flying today and a few others also had glasses and those that did said that the goggles felt fine and they could clearly see the screen. That's good news. But I don't want to fly with my reading glasses on, since when I raise the goggles I need to remove my glasses in order to see far away! So I ordered the DJI focus inserts and hope those will have the same effect as my reading glasses.

Thanks for sharing the technical details above.

If the DJI Goggles came with a lens power of 12.5 diopters in the first place instead of 10 diopters you would not need to use your reading glasses and you would also not need to purchase a pair of DJI focus inserts!

 

[DocPat]

At the very least DJI should be supplying their Goggles corrective lenses free of charge as an interim work-around for the design flaw in this product.

 

[DocPat]

The DJI Goggles have a fixed focus requiring the user to focus at less than 12 inches! Nobody watches TV at that distance. Stupid design fault.

 

[DocPat]

For all those people having focus problems with their DJI Goggles, I re-measured the distance from the lens to the LCD screen and it is 7 cm. This means the DGI Goggles screen is at a virtual distance of 23cm or 9 inches. If you can focus your eyes on this distance then the screen should be clear. If you need readers at this distance then you will also need them for the goggles. The problem is when you want to lift the goggles to view the drone. In this case you will have to remove your readers also. Ideally the goggles should have adjustable focus to suit all, but a simpler solution would be if DJI would increase the strength of the DJI Goggles lens from 10 diopters to 12.5 diopters. This means that an INCREASE in lens power is required by the DJI Goggles of 2.5 diopters. This would be a small change with negligible affect on the weight or cost of the goggles. With this power the DGI Goggles screen would be at a virtual distance of 56 cm or 22 inches and most people would not need their readers or have to add corrective lenses to their DJI goggles. If DJI feels they have no obligation to recall or exchange the goggles with the original underpowered 10 diopters lenses, then they could at least make available a kit of 12.5 diopters lenses as a free upgrade to all those affected. It would then be a simple matter for anyone with an once of DIY sense to remove a few screws and replace the lenses themselves and the problem would be solved.

 

[DocPat]

It appears that, instead of correcting the focus problem for free, DJI is actually capitalising on this design fault by selling corrective lenses through their DJI Store for the excessive sum of $49 AUS !! Is this the real reason DJI is not admitting to this design fault? If so then this is a very bad and dishonest way to do business. A third party company is also selling corrective lenses for the DJI Goggles and they state that the user has to be able to see clearly at nine (9) inches, otherwise corrective lenses are required. This is a direct confirmation by an independent third party that the DJI Goggles have a basic design fault due to under-strength lenses.

 

[thecorpral]

It appears that, instead of correcting the focus problem for free, DJI is actually capitalising on this design fault by selling corrective lenses through their DJI Store for the excessive sum of $49 AUS !! Is this the real reason DJI is not admitting to this design fault? If so then this is a very bad and dishonest way to do business. A third party company is also selling corrective lenses for the DJI Goggles and they state that the user has to be able to see clearly at nine (9) inches, otherwise corrective lenses are required. This is a direct confirmation by an independent third party that the DJI Goggles have a basic design fault due to under-strength lenses.

I really like the way you explain the issue, I like many have issues with focusing on the screens, and like very few, took a trip to the optometrist for a eye check, and ended up with 1.00 reading glasses.

However I don't like wearing the goggles with the glasses, and currently have 3 sets of the DJI Goggles corrective lenses on the way, in 2.0D, 2.5D and 3.0D, they have just left China today so hopefully will get them to Australia by next week sometime.

I'm interested to know how diopter strength works, lets say for example that the strength of what is in the goggle as standard is 10.00, does adding the DJI 2.0D then increase the total to 12.00, or adding a 3.0D increase the total to 13.00?

Or does it work a different way.

Anyway, thanks for posting about this as it has been very hard to find anything informative to read about this problem.

 

[DocPat]

I really like the way you explain the issue, I like many have issues with focusing on the screens, and like very few, took a trip to the optometrist for a eye check, and ended up with 1.00 reading glasses.

However I don't like wearing the goggles with the glasses, and currently have 3 sets of the DJI Goggles corrective lenses on the way, in 2.0D, 2.5D and 3.0D, they have just left China today so hopefully will get them to Australia by next week sometime.

I'm interested to know how diopter strength works, lets say for example that the strength of what is in the goggle as standard is 10.00, does adding the DJI 2.0D then increase the total to 12.00, or adding a 3.0D increase the total to 13.00?

Or does it work a different way.

Anyway, thanks for posting about this as it has been very hard to find anything informative to read about this problem.

Hi Corpral, you can work out the strength of a lens by measuring its focal length in meters and finding the inverse. For example, focal length of 50cm is 0.5meters. The inverse of this is 2. Therefore the strength of the lens is +2 diopters. If you add two lenses together the combined strength is simply the sum of the individual strengths. If you know the stength of a lens you can work out the focal length by the reverse process. For example a lens of 10 diopters has a focal length of 10cm. Hope this helps.

 

[jc930]

Hi Corpral, you can work out the strength of a lens by measuring its focal length in meters and finding the inverse. For example, focal length of 50cm is 0.5meters. The inverse of this is 2. Therefore the strength of the lens is +2 diopters. If you add two lenses together the combined strength is simply the sum of the individual strengths. If you know the stength of a lens you can work out the focal length by the reverse process. For example a lens of 10 diopters has a focal length of 10cm. Hope this helps.

Thanks for the explanations.

I was unsure which diopter I need for my goggles. Many sites simply suggest adding 1 diopter to the reading glasses for the corrective lenses, which seem kind of imprecise.

I use a reading glass of 1.25x power (diopter=1.0D) to read my computer screen about 22 inches away. Using your calculation I figure I would need 3.5D diopter lenses (2.5D for 22 inch virtual distance + 1.0D for reading glasses).

For 3.5D the virtual distance would be about 50in, and at that distance I can read the text on my computer screen without reading glasses. Actually I found 3.0D would probably work for me as well (31in virtual distance).

Thanks again.

 

[sadarahu]

YOU MIGHT BE WRONG

Before you do anything or try to discuss fixing your viw - first compare your googles with another identical model. I tested my friend googles (identical) and the difference was about 20%. I thought it was my vision but NO, it is DJI crap ! quality that sucks ! I am totally disapointed and so far see no way to adjust it, so if one knows the trick then let me know.

IF DJI read this post - if would be fair to offer free fix to improve your reputations because at this moment I can say DJI QUALITY SUCKS !