Vroobel

Yes, I know they are cheap now, I'll consider it in future. I don't do it for sale, so at this moment it's not important how it looks on the board.

Years ago, before that technology appeared in the marked, I made plenty of custom circuit board on my own. Initially I used an oil marker to create the paths to replace it with set of liquids: one to spray a laser printout to make the white space UV-transparent and second to cover a raw copper laminate. After exposing the laminate through the printout on UV rays the uncover area was easy to etching in nitric acid or later in ferric chloride. Now we have so affordable technology, but I'm simply happy to make my circuit working.

Here is how the smaller version of the dew heater controller looked during assembling and straight after.

They are not only skills. I finish an Engineering (Advanced Manufacturing) course this year, so serious job offers are welcome... 🙂

Hi,

Testing my new home-made 4-channel smart dew heater controller, dedicated for imaging. Works as expected.  

Hi, 

It's pointless to take the battery-powered smart dew heaters controller every time I want to capture DSOs using my 90kg EQ fork mount. Therefore I decided to build a smaller version of the heaters controller without the focuser control feature. It will be powered from 12V like other elements of my setup. The same built, the same code for the Arduino nano. 

😏🙂

Exactly. The difference is that I am in the North West, they are somewhere on the opposite side.

Unbelievable! Some guys here on the SGL were laughing at me because of my dew heaters attached to EPs in my binoviewer... Where do you live? 

That's because of the 289mm FL and the F/4.1.

I think here is misunderstanding, my lens is TAIR-3-PhS 300mm F/4.5 which is written on its tubus. When I was updating acquisition data at the astrobin I found out there that it's 299.8mm FL.

I'm confused...

On 09/01/2023 at 23:02, Gfamily said:

Haven't been able to find any ray diagrams for it, but there's information here that might be of interest 

https://joseph-tang.blogspot.com/2017/11/tair-3-300mm-telephoto-lens.html

https://allphotolenses.com/lenses/item/c_857.html

http://photohistory.ru/1207248188998898.html (in Russian)

Hi,

Thank you for the links, they are useful. .

On 09/01/2023 at 22:46, vlaiv said:

I don't think it is possible without knowing parameters of the lens - like focal length.

We could perhaps make some assumptions based on shape of the lens, and say that left one is achromatic pair - telescope lens and that second is focal reducer and then ray diagram might look like this:

(black lines are at 0 degrees and red lines are at slight angle and focus at some distance from center of sensor / optical axis).

Oh, my God, I forgot to write it. It's 300mm FL lens.

Hi,

This time something completely new: picture of the California nebula taken using my recently modified TAIR-3-PhS 300mm F/4.5, the vintage Russian lens for Zenit SLR.

I know that the background of the picture is not perfect, but even with modified Canon 6D, ISO 1600 and 300s exposure, subs appear quite dark. Now I think that the lens would be very good under dark sky with no filter. I'm tired now after a 4 days battle with the post processing, but I will consider reprocessing.

Look please at the corners: stars are pinpoint, so it has an obscenely flat field.  😯

57 of 61 x 300s, ISO1600, 30 flat frames and 20 of darks and biases.
TAIR-3-PhS 300mm F/4.5, ZWO EAF, Optolong L-eXtreme, modded EOS 6D.
And of course, my Opus Magnum mount.

And Rev. B:

Hi, 

David and Goliath that means the TAIR-3-PhS on top of my Opus Magnum mount before the California Nebula hunt. It will be its first light and check of a field curvature, as it works with a full-frame camera. It's fastest scope I have: 300mm F/4.5.

Hi,

I use an older version of the 102EDT sold in 2014 and the EAF works perfectly. I guess the focuser still keeps the standard. 

Hi,

It had to be a test of the EAF settings towards work with the EKOS and its linear algorithm, but accidentally I obtained the Andromeda...
The only clear night in Liverpool since 15th December, unfortunately accompanied by 83% of the Moon.

40 of 46 x 180s, ISO1600, 3 x 30 calibration frames
Altair 102/715 EDT, IDAS LPS-P2, Planostar x1.0 FF, modded EOS 6D.
And of course, my Opus Magnum mount.

Hi,

I hope this is proper section for may question.

Is someone able to draw a shape of light beam in the lens presented in the picture below? The vertical thick line on the right side is called "imaging plane", so I assume that earlier it was a photo film, but now it's the sensor. The thick lines in midle indicate position of iris and let's leave it fully open.

Hi,

Because of the clouds and rain I performed a test of night focusing through a double glass.

ISO3200 10s :

ISO1600 10s :

ISO400 0.5s :

I'd like to mention that 5 single pulses of the EAF makes a visible difference, while 10 pulses means significant change. A calculated earlier (New) Critical Focus Zone gave me an initial step in the focusing process of the Ekos equal of 13 single pulses. That means the perfect focus should be found in a range of +/- 5x13 single pulses. I have to add that 1 single pulse moves the lenses 1.37 μm ! In the case of my Altair 102EDT F/7 similar 16 pulses very next to the focus point changes the HFR from 1.4 to 1.5.

The first move is to roughly find focus using the Bahtinov Mask.

I'm going to choose the California Nebula and a little bit of its surrounding as the first DSO. My 102EDT F/7 cannot capture it properly, so that's a goal in general. I don't aim in the wide field (yet?), but buying i.e. the RedCat just for some occasional play is in my case wasting money. 

Sure, I'll send PM when I'm ready. There is some explanation needed, so I have to prepare it.

Thanks.

I think so, the EAF has internal gear ratio 120:1, while my pulley has 125 teeth and the EAF pulley has 20 teeth that gives 6.25 ratio. It moves very slow, like a snail. Maybe even the snail is faster... 😂

The funny fact is that the Tair allows to focus on 3m far items, but that feature will be never used. The whole range is around 30,000 steps, so I will use maybe 1000 of them. I'm go ing to perform a proper NCFZ (New Critical Focus Zone) calculation for this set and its backlash.

Hi,

I'm pleased to introduce my new small ATM project: the Russian TAIR-3-PhS 300mm F/4.5 lens adapted to the purpose of astrophotography. "Adapted" doesn't mean verified yet, I just finished working on it and will try to test it ASAP, but it works under control of INDI/Ekos.

I have it thanks to @rnobleeddy who sold me recently the set called "Zenit Photosniper". This is not a usual lens, especially focusing is... weird. It's because of the whole set: 

http://camera-wiki.org/wiki/Zenit_Photosniper

After its arrival I began thinking how to turn it into another setup. Some parts landed in the box, some others I bought and others I designed and printed. Most funny thing is that the ZWO EAF is 3.5 times more expensive than the lens... 😄

If the one in your avatar is made on your own, then I love it! It's most beauty cute house for the telescope! 😍

But not, I canot do it. Someone ask the same question in YT comment, so let me please quote myseff: I would really like to do it, but it's not my possesion and it's not best place, houses and trees around limits my view. I would consider a static caravan...  

I can consider the observatory, if I move to my own place. 

Thanks

I didn't think about the clouds, when I was drawing sketches... The ATM/DIY keeps me busy all the time. I would die of boredom waiting for the clear sky. My mount was outside around 10 times in the 2022, including work on its improvement and tests. 😠 

42 minutes ago, Stu said:

Another session with the FC100DC. Enjoying both the MaxBright IIs and the Bino Bandits, they work brilliantly together. I’m set up well now, also with two dew strips on the binoviewers which keep the eyepieces nice and clear.

I also did a quick test for @Saganiteand found that they come to focus easily without a GPC when attached directly to the Baader T2 mirror diagonal, very handy.

If I properly understand, is the Bino Bandit a double eyecup with heaters? Could you please share some details about that with me (us)?