E.R.T
"The astronomical experience, at your fingertips"
Educational project to discover optics and some sky objects: moon, bright galaxies, star clusters...
Simple and educational assembly
Discover how to easily assemble the E.R.T telescope. Each module has only one mounting direction for optimal learning.
Quick demonstration
Overview of the E.R.T telescope assembly in short version.
Modules and specifications
Included modules
| Lens barrel | Main objective |
| Baffle | Stray light blocker |
| Optical tube | Main structure |
| Focuser | Standard 1.25" |
| Diagonal | With prism |
| Eyepiece | Included |
Characteristics
| Type | Astronomical telescope |
| Optics | Achromatic doublet 50/200 |
| Eyepiece | 20mm |
| Usage | Educational/Initiation |
| Assembly | Intuitive, one-way only |
| Observations | Moon, clusters, galaxies |
| Recommended age | Assembly to be done with an adult |
Pedagogy
| Objective | Optics discovery |
| Learning | Telescope assembly |
| Understanding | Optical function |
| Practice | Direct observation |
| Support | Documentation included |
| Evolution | Towards advanced instruments |
Filter holder
The ERT pack includes a filter holder compatible with standard 1.25" filters. You can install different types of filters according to your observation needs: moon filter to reduce glare when observing the Moon, or UHC filter to enhance nebula contrast for example.
Project gallery
Complete E.R.T Kit
Complete E.R.T Kit
Printed parts + assembly kit
- 3D printed parts
- 50mm objective lens
- 25mm eyepiece
- Diagonal prism
- Detailed assembly instructions
- Educational support
- Some sky objects to observe
- Integrated mount
As each part is handcrafted, please allow approximately 20 days for manufacturing, plus shipping time.
Educational benefits
Learning by experience
Intuitive assembly that helps understand how an astronomical telescope works.
Real observations
Allows observation of the moon, star clusters and bright galaxies.
Modular design
Each module has only one mounting direction to avoid assembly errors.
Scalable
Excellent introduction before moving to more advanced instruments.
What our customers say
"Happy owner of a Seestar S50, I ordered the accessories that Raphael offers (baffle, dust cover, etc.). All these accessories attach perfectly to the Seestar, without forcing, and hold really well! An essential addition to this little machine. Raphael perfectly masters his designs, the dimensions, and his printing! 100% approved!!"
"I bought these 3 collimation knobs for my Orion XX14i Dobsonian. They replace my old steel screws which, although sold for this purpose, did not have rounded ends and ended up punching the back of my secondary mirror support. The ones from La 3ème dimension are nicely rounded, which makes the adjustment much smoother, without jerks and much more precise. Very satisfied, thank you!"
"I asked Raphael to design several Bahtinov masks in different sizes for me. The work done is impeccable, and done with seriousness and rigor. I am fully satisfied. I will not hesitate, in the future, to call on his expertise."