Holographic helixes - FAQ

Holographic helixes, also known as holographic fans, are gaining momentum in the point-of-sale marketing, signage and trade show industries. More and more companies want to use this medium to promote their image and distinguish themselves from the competition. It is true that the effect is amazing, not very known for now and very good at generating the "wow effect" desired in marketing in general.

But as this technology is still very young it is to be explored in more details, moreover it is in constant evolution and innovations arrive very quickly, it is thus necessary to keep up to date. At Holopix we have been around since the very beginning of this medium and we have not stopped following it since then. So we have a great experience and a very good knowledge of these propellers. Here is a summary of the questions that our customers and prospects ask us most often, and the answers that we give them of course.

1. How does a holographic helix work?

A holographic helix works on the basis of the retinal persistence. It is the phenomenon according to which an image remains on the retina of the human eye during 1/25th of second, it is for that that the films are a sequence of images at a frequency equal or higher than 25 images second in order to create a continuous movement. In the case of holographic helixes it is the speed of rotation of the helix coupled with the frequency of lighting of the LED present on the blades which will use this phenomenon. Let us take the example of a traditional fan, if you place an LED on one of the blades of the fan and that you make it turn you will appear a circle because each position of the luminous point remains on the retina of your eye during 1/25th of second and because of the speed creates a continuous movement which makes you see a circle instead of a bunch of points. The helixes contain a very large number of LEDs (which vary according to their size), their rotation will create images. In addition, the speed of rotation of the blades is such that the eye cannot see them, so they become invisible and you really get the impression of an image floating in the air.

2. At what distance is the image projected?

This is a question that comes up a lot when it normally wouldn't. Indeed a holographic helix does not project an image, it displays it like a screen would. The mistake comes first of all from a misunderstanding of how the helixes work (see explanation above) and also of some images that have been circulating on the net showing a shoe above a holographic propeller as if it came out of the propeller and appeared above. It is thus necessary to understand that the image appears at the level of the blades of the propeller since it is the rotation of those which will form the image.

3. How many videos can you run on a holographic helix?

The number of videos that can be displayed by a holographic helix is only conditioned by its storage capacity. There is no limit to the number of videos. Some propellers allow you to manage their playlist very easily, switch from one video to another, change the order of broadcasting, create loops, you can manage the programming of your propeller as a musical playlist on your favorite player. However, not all models offer these advanced features. Ask before you buy.

4. What is the storage capacity of a holographic helix?

The capacity of the propellers will depend on the model. The older generations generally offer 4 GB while the new ones have at least 8 GB and often 16 GB. This means that you can put up to several hours of video in the memory of your holographic helix.

5. How to put a video in a holographic helix?

There are several methods depending on the models and brands. First of all, many propellers offer memory integration through an SD card that can be accessed to take it out of its compartment and plug it into a computer (the SD card reader for a computer is usually provided in the propeller package). Some also offer the possibility to access the SD card through a mobile app, so without having to remove it from the propeller. High-end models offer direct wifi integration. The propeller emits a hotspot to which we will connect in wifi with the device that contains the video (phone or computer) and the integration will be done through an app or a software designed for this purpose. Finally, some models require a wifi social media connection. The propeller must first be configured to connect to the wifi network of the location where it is located, then you can access its memory through an online interface. According to our experience, we do not recommend this solution, as it does not seem to be optimal (very long loading time, recurrent loss of connection etc.).

6. How is a holographic helix installed?

Every holographic helix is supplied with a small wall bracket. The propellers being all relatively light it should be enough to make two or three holes in the wall to place the support and fit the propeller on it. In general, a small security screw is used to secure the propeller to its support. For an ephemeral use it is however possible to place the propellers on a stand (tripod type). That way they are easily positioned and moved, which is of great interest during trade shows or any other event.

7. Can a holographic helix work horizontally?

Yes, it is quite possible to imagine a holographic helix fixed on a ceiling offering to the viewers who look up a hologram effect. We can also imagine a glass floor with propellers placed underneath to make holograms appear under the feet of the passers-by. However, be careful with the viewing angle, which should be as front as possible. However, most of the implementations are made with propellers placed in vertical position at a more or less important height according to the desired effect and the size of the model.

8. Does the rotation of a holographic helix make noise?

A holographic helix rotates at more than 700 revolutions per minute, so there is bound to be some noise, which will vary depending on the model. The noise level of a rotating propeller is about 55 to 60 decibels in the immediate vicinity of the propeller, but it drops very quickly when you move a few meters away. The use of a protective shell has the effect of strongly attenuating this noise. In concrete terms, a rotating propeller without a cover is not at all disturbing in an environment such as a sales outlet or trade show, but it should be taken into consideration a little more when it comes to quieter environments such as a conference for example. Please note that some less qualitative models also produce a motor noise in addition to the blast, so be sure to ask about it because this noise can become very disturbing during long exposure, in a sales outlet for example.

9. Can the image diffused by a holographic helix be seen from different angles?

No, the holographic helixes offer a viewing angle of 160° approximately, which means that it is necessary to be more or less in front of the helix to see the contents that are displayed. If you go to the side or behind the helix, you won't see anything at all. That's why we talk about holographic simulation and not about the original meaning of hologram. That's why it is recommended to fix the propellers on a wall, it will avoid the disappointment of a viewer who would try to go around the propeller to see the back of the image that he was admiring.

10. Can several holographic helixes together be synchronized together?

Yes, some models offer this possibility, but be careful, not all of them can and not all of those that can, can in the same way. As a reminder, synchronization allows you to connect several propellers together in order to create a larger image, it is a complex process, it requires first of all to place the propellers in a very precise way, taking care of course that they do not touch each other, but while superimposing them to keep a continuity in the image. There are grids designed to accommodate the helices that you want to synchronize. There is no real limit to the number of helices that can be synchronized, it all depends on the size of the image you want to obtain. You then have to cut the video into as many parts as you have propellers according to a very precise diagram and then you have to place all these pieces of video in the propellers that correspond to them. Finally, you have to wire all the propellers together to synchronize their start. Some models offer a feature optimized for synchronization, they allow to couple the propellers between them on a web interface that takes care of the video cutting. This is a brand new feature that needs to be carefully studied.

11. Can a holographic helix broadcast sound?

No, to this day there are certainly models that offer a beta bluetooth function to couple a connected speaker to the holographic helix, but the tests are not conclusive, so we will have to wait a little longer, as this possibility should be released soon.

12. Can a holographic helix be controlled remotely?

It all depends on the model. Some offer this possibility in a more or less optimized way. Our range offers several remote controllable models with a very efficient and ergonomic interface. If remote control is an important criterion in your purchasing process, make sure you know what is possible. You should be able to access all of the prop's functions, from video streaming to advanced settings. The cloud must be stable and in English at a minimum.

13. How heavy is a holographic helix?

Depending on the model, a holographic helix weighs only a few kilograms. They are very light and therefore very easy to install and move.

14. What is the size of a holographic helix? and the size of the image that is diffused?

In term of size there are several things to consider: first of all the diameter of the helix, which will also determine the maximum size of the image that one can obtain. For example, a D50s propeller is 46.8 cm in diameter, so the maximum image will be a circle of 46.8 cm in diameter. The largest model, the D100, is 90 cm in diameter. We can also consider the size of the transport box if you want to move your holographic helix regularly. Again it depends on the model, some propellers are delivered assembled and ready to be plugged in, while others have blades that require to be assembled. Thus the package of the D100 is smaller than that of the D60H to take models of our range. If this creteria is important to you, think of asking your consultant. As an example, a D100 is delivered with the blades removed in a box smaller than a carry-on bag, so it is very easy to transport.

15. What is the definition of a holographic helix?

The definition is related to the number of LEDs on the propeller blades. It is very important to understand that it must be related to the diameter of the propeller. Thus a helix of 90 cm in diameter in 1024*1024 will not necessarily provide a finer image than a helix of 47 cm in 512*512. What makes the fineness of an image is the number of LEDs to the m², out there we understand that it is identical, since on the 90 cm we have more LEDs but also more surface. One will be able on the other hand to see a difference on 2 propellers of the same diameter (ex: 65 cm) of which one would have a definition of 720*720 and the other of 1024*1024. There are more LEDs for the same area, so the image is thinner.

16. Can a holographic helix be used in full light?

Yes, the holographic helixes are basically designed for POS and signage or trade shows. They emit a light varying between 800 lumens for the smallest models and 2000 lumens for the biggest ones. They are therefore optimized for use in neon or daylight conditions.

17. Can a holographic helix broadcast a photo?

Yes it is possible but not necessarily recommended. Indeed, the propellers integrate standard photo formats such as jpeg, jpg, etc. However, if the image is not worked in a 3D spirit, the hologram aspect is lost. If your photo has a background, the impression that the object is floating in the air disappears, and if there is no 3D work on your photo we will see in the end simply a flat and slightly transparent image. Finally, we are deprived of the movement and the play on depth that strongly adds to the hologram effect.

18. What type of video to broadcast on holographic helixes?

First of all in terms of format, the propellers integrate all the standard formats (mp4, mov, avi, etc). Note that the software will first convert the video file into a format that is specific to the propellers (often a .bin), then transfer it into their memory. Then for an optimal result the video must have some specific characteristics:

• A square format with a 1:1 ratio. Indeed the propeller produces a round image, it is thus necessary that the basic video is with the format 1:1 under penalty of undergoing deformations (crushing of one of the dimensions) once read by the propeller.

• An image that fits in a circle. Think about it, the image produced by a helix is round, if your content goes outside the circle the viewer will see the boundaries of the helix and the magic will slightly fade. The image must therefore be contained in a circle itself contained in a square linked to the definition of the helix or slightly larger (e.g.: a square of 1024*1024).

• A totally black background: the hologram effect is largely due to the fact that it looks as if the object diffused on the helix is floating in the air. For this you need to make the background around the object disappear completely, i.e. a total blackness that will not be read by the propeller.

• 3D objects: the impression of relief must be as important as possible to reinforce the impression of an object that floats and that one could catch.

• Play with depth: the 3D aspect will be reinforced if your object moves and if we see it move forward and backward during its broadcast. This criteria is not essential, but depending on the effect you want it can be an addition.

19. Should I use a protective case with the holographic helixes?

Again, it all depends on what you want to use it for. The protective case provides two major advantages. First of all of course it prevents the viewer from trying to touch the image, which can happen as the concept still amazes many and people naturally try to understand how it works. Secondly, it greatly reduces the sound of blowing due to the rotation of the propeller. So it can be very useful for use in a quiet environment, even if there is no danger of contact with the public. The larger models offer the possibility of having a square shell that allows the propeller to be placed on any flat support such as a table, shelf or other, this is a third possibility to consider the usefulness of a protective case. The difference between the result with and without a case is up to each person. Personally I like the result of a propeller in a square case.

20. How do you control a holographic helix?

There are several ways to control a propeller depending on the model. Most of them offer at least a remote control, some more basic than others (ON/OFF function only until the playback and brightness adjustment functions). Then there are the applications, offered for the mid and high end models and PC/Mac software for the high end. The simplest models just offer video upload and on/off functions while the most advanced models offer many settings (image angle, brightness, timer, autostart etc.) find out how to control the propeller you want to buy, it is often very correlated with the quality of the product.

21. What is the life span of a holographic helix?

To estimate the lifespan of a propeller we talk in number of hours of operation. Most models are given between 30,000 and 50,000 hours (which is 6 years non-stop). Of course, the technology being very young it is difficult to have a perfect hindsight, that is why it is also important to look at the guarantee conditions offered by the salesman.

22. Can a holographic helix work on battery?

Yes, first of all some models are made for that, it is small models that are around 30/35 cm of diameter which offer an integrated battery to be able to place them on shelves as simply as possible. Then the biggest models work in 12 or 24 V, they are supplied with a 220 V adapter of course but it is quite possible to make them work with a battery that corresponds to the same voltage. The power connection is standard and easy to connect to the battery terminals.

In any case, there are many models and brands of holographic helixes, so it is suggested to get the right information before buying and not to look at the price as the only criteria before buying.