A new aerial system for long lenses

Through the years i have imagined a mounting system for the long aerial lenses that are easy to use and maintain.

All my variety of mounting style for the long lenses on tables are good but there's a lot of pain of moving the tables all around and mounting every time the Dobsonian mount on top also its risky that i can fall at these heights with the Dobsonian mount in one hand.

So o decide to construct a new mount that can be moved around easily.

It consist of a frame 3m high in which the eq1 mount mechanical part can be mounted.

The frame can be attached to a pillar for reaching bigger height's.

All of this mount can be moved around the courtyard.

To move the eq1 mount on top i have attached two sticks the main one has a length of 1.3m and the other is for balance.

It's a very easy system to use not difficult at all and the advantage is that it can be easy to align the objective lens using the long stick has an view point.

A good method to make sure that the lens os parallel to the object in view and collimated you need to put the object in the center of the lens, move 2 or 3m away and view the objective cell internal diaphragm that in these case must pe concentric all across the lens and using this method you are pretty align and ready to view the object at the focus point with a eyepiece in you hands.

I don't need a long cord to center the objective lens.

In the last year 2023 and 2024, I evolved and acquired with difficulty 3 singlet very unique large objectives with useful diameters of 76mm with a focal distance of 9.2m and 85mm with a focal distance of 11m.

True monstrosities in the true sense of the word.

Of course, the full diameter of the lenses is larger, but they are used with a chromaticity index between 1.5 and 1.8.

The 76mm lens with a full diameter of 95mm and used at 76 and 70mm and the 11m focal length lens with a useful diameter of 85mm, is a copy of the famous objective lens used by Cassini in the discovery of the division that bears his name and of the Saturnian satellite Rhea.

I can confirm that Cassini was able to see the division through the observations made with these lenses also the moons tat he discoverd with this lens.

Technical data:

Objective lens with a focal length of 9.2m

Material - fused silica glass

Thickness 5mm

Gross diameter - 95mm

Useful diameter – 76mm and 70mm

Chromatic index 1.5 – 1.8

Objective lens with 11mm focal length

Material - soda lime glass

Thickness 4.6mm

Gross diameter 95mm

Useful diameter 85mm

Chromaticity index of 1.5

The lenses are made to mimic the quality of 17th century lenses, having almost the same performance as the best Campani lenses from that period.

They are modern replicas of Campani lenses having the same thickness as the lenses of the 17th century.

The 95mm diameter and 11m focal length lens

This fall 2024 I purchased a photo tripod that I modified to mount aerial lenses with a long focal length. The maximum height I could reach is 3.2m and practically with the lens of 5.5m focal length I can reach a maximum height of 30 degrees and with the 9.2m 23 degrees maximum height in the sky.

So any object from 22 degrees below can be observed in the same way and in the case of the 5.5m lens everything below 30 degrees can be seen.

In order to reach a larger heart, I will have to use the wooden frame mounted on the iron pilaster.

The long telescopic tripod for aerial lenses maximum 3.2m high.

It's a real pleasure to use the eyepiece with such lenses, first and foremost, I don't have to deal with chromatic aberration, it is almost non-existent in focus with large lenses with a long focal length, only in extrafocal and intrafocal you can see it, but between the two the image is super clear .

Planetary results.

Saturn

The 65mm 5.5m objective lens

Using the 65mm diameter lens with a focal length of 5.5m, I have some superb visual images up to 171x eyepiece 40mm plossl.

You can see the details on the planet's disk, such as the northern band of clouds at 171x even at lower powers.

The Titan satellite is visible with peripheral vision at lower powers, for example using an 80mm Kepler eyepiece and a 68x Titan magnification is easy to see, even at 132x magnification with a 40 mm plossl.

I don't have vibrations, that is tremors in the eyepiece image, especially if t sit down on the grass or on my knees, lying on a duvet or on a chair, even standing up i have a stable image.

Observations without an eyepiece that is without a means of interposing a lens in front of the eye.

Since I have quite high myopia -5 i can observe the magnified image directly through the objective lens in the focal plane, thus providing a magnification calculated at my dioptrice of 50x.

Where I can see a particularly clear image much clearer than through the eyepiece with a special contrast, the visual field is limited, it's like looking through the hole at the end of the tunnel.

The visual field somewhere at 50 arc seconds degrades larger than the diameter of Jupiter at opposition is like a hologram in the distance a very magical experience.

It's very strong but the contrast is excellent, Saturn is half the field of view and you can see the rings clearly in the first one better than Galileo Galilei, so an image at 50x the colors are very vivid, the planet's disc is a pale yellow and the rings are a light gray .

Jupiter

Simply magical an exceptional image at 171x, some jaw-dropping details, but the clearest is without an eyepiece directly through the objective lens where the cloud bands have an excellent contrast, you can see the bands very clearly, the disc apparently as close as the visual field to the opposition , the bands have a reddish / pink color.

Moon

A splendor with and without eyepiece no comment.

With 9.2m 70mm diameter lens.

Results and better, image without chromaticism in focus i tested the lens using Kepler eyepieces of 220mm, 80mm, 70mm, 60mm 100mm, 140mm, 170mm focal length.

And Huygens 50mm, 45mm, 110mm length.

They all provided special images where i could easily observe the Saturnian satellites, Titan and Rhea, discovered by Huygens and Cassini visible through the 76mm diameter lens.

Without an eyepiece, Saturn is big observed in focus where the rings almost touch the edge of the field of view, with my myopia I get around 83x and the planet is bright and very clear without chromaticism around, a special apochromatic image in the true sense of the word, can be noted the bands of clouds on the disc if you concentrate to see this details.

The ring having a light gray color and the disk a pure yellow.

I have such an extraordinary contrast without an eyepiece because it is only my eye the objective and the cristalin lens without anything else to get in the way, remarkable results are obtained.

I have no problems with vibrations during this type of observations, but I have to position myself loosely and keep the planet in the field as much as possible, it requires a bit of training, but once you get used to it, it's a easy. It takes a while until you find it in the field of the lens, then I take off my glasses and look.

With 11m focal length objective lens

I obtained remarkable results with the provided eyepieces, and the maximum magnification is about 250x using a Huygens eyepiece with a focal length of 45mm.

But I limit myself to smaller magnification like 100x 150x.

I have no chromaticism in focus at all apochromatic image in focus, at 100x 150x even 220x.

Recently at Saturn i observed the satellites Iapetus, Rhea and Titan using an 80mm Kepler eyepiece 137x magnification. The moons was also visibile at 78x magnification with a 140mm Kepler eyepiece lens.

If you increase the magnification power, the satellites disappear, so you only see them at a certain magnification.

At 220x using a Huygens 50mm eyepiece, i noticed the band of northern clouds and the gap between the ring and the other side, which starts to disappear next year and the ring will be parallel to us.

Too bad the ring is tilted so we could test if the Cassini division can be seen at 85mm.

I will wait until the following years when the position of the rings is more favorable.

Without an eyepiece, the planet is larger than the observed field of view and it looks amazing at first sight with no chromatism the bands of clouds visibile, the magnification with my myopia is around 100x without eyepiece.

It is the most difficult lens to use due to the space i have, so I am limited in using it only in key moments, I can use it when the object is positioned in such a way that the space is clear and wide and the object is about 20 degrees high.