spectro-aras.com

Buona sera Umberto,

These results are well because Tim's design is very good.

Grazie mille per la tua finezza, Joan.

Hi.

It's just a thought.

JG.

Some results more. JG.

Hello,

Two observations more.

JG.

Hi,
Three more.
J.G.

Details around V694 Mon.
JG.

Rigel,

JG.

Hi,
The Moon at last night through fog and clouds. It was impossible observe any star.
Echelle NOU_T with aluminized mirrors result.

The Order #56 it's seems been consolidated.

J.G.

Hello,
In my opinion, the Noct-NIKKOR 58mm. F1.2 is usable for spectrofraphic jobs, it isn't as better as the Nikon 85mm. F1.8, or rather, they are two different things.

I would like to remember that the Noct is a old objective with an aspherical lens and only were made around 13000 units until 1997. See, https://www.kenrockwell.com/nikon/58.htm. From my point of view, the Noct as the best objective with a notable difference as others ones 50 to 58mm. for a reflex cameras. Nowadays they're designing new very good objectives but for mirrorless bodies, I don't know how I could use them with their short back focus, another deterrence point is their price, around €9000 for a Nikon 58mm f/0.95, with 17 lenses, three of them aspherical, total weight 2 kg.

Well, I leave he some pictures, you can see a Check2 and four results, I would like to add that if you would like to observe with full resolution the ordes IR and UV, you only need to bring to focus these ones, and that it's all, in this way you can detected the Order 57 in some ocassion. I think it's good see the IR and UV zones, although being at low resolution now.

About the not appersement of the Orders 30, 29, 28, 27,..., it is due that ISIS can't discrimene them, because they are really too near. It could be fix, first, with a new CCD with pixels around 6x6, ( I don't hae any of it ), and/or second with change the equilateral prism for a 300 l/mm. transmision grating.

With the Noct I've reduced to halve the integration times and suppose I've won a magnitude. In fact I be able to observe the main spectral zones for the most part of studies.

J.Guarro.

Hello at all,

These two last nights I've tested the NOU_58 with one 40 microns pinhole. The theoretical resolutions has been about 10000. But it is a bit far of the reality. The matter is, the orders narrowless add the inclination of these ones referent to horitzontal lines of pixels in the CCD chip, the resulut of this is noise and a possible graphic distorsion.

You know the rule that says that the division the pinhole or slit size per the pixel's size no be able to inferior to 3. This rule working well when the spectral image is paralel to pixel lines but not when are between their ones a strong inclination.

In this case, 40 / 9.08 = 4.4, but that isn't sufficent. I've returned again to 50 / 9.08 = 5.5, the noise efect, and stability improve, certainly the R fall down to 8500 but it is compensed with 64% to more light.

With the NOU_58 we are looking for a more weak objects. The main surprise is the current R8500, all of us thought that it had be around of R6000/7000.

J. Guarro.