festoon

Thanks @Paul M.

I did see in Sky Safari SES-6 and the nearby USA 170 but thought they were too far away from the actual path to be them. 
I guess the satellite paths are accurate?

I had never thought before that military satellites would not have published data...so this could very well be the mystery object!

Was looking through my imaging subs the other evening (from 10/02/21 between 23:09 and 23:14 Uk time - location Cambridge, UK) and saw what looked like what I thought was a satellite.

The subs are 10 seconds long and animated in this GIF

I was intrigued to look on sky safari as what I was looking at - because it took approximately 5 mins to cross my field of view - rather long I thought for a satellite. However, no satellite/object is registered as passing on that date or time.

Any ideas/suggestions?

I don't know if this makes a difference, but does not image scale and focal length make a difference when comparing these charts. The DL will be relatively more magnified than the DZ, or are these scales normalised for focal length?

In my experience it’s a really nice camera. It’s ICX825 sensor is very sensitive and with being cooled there is very little dark current.

The only down side compared to a DLSR is the sensor chip size at 11mm diameter.

I mainly used this camera paired to a C5 with a f/3.3 focal reducer for EEVA but did save a few of my stacked fits with 5-10 minutes total exposures

Do you mean Atik 414ex colour?

If so yes I do have experience using it. Any specific questions?

4 minutes ago, Spongey said:

Using a QHY600 short bfl version or 268M with the corresponding filter wheel gets you to 34mm / 29.5mm respectively, which leaves you enough room for a 10mm lens adapter. I plan on using my 268M with my Samyang 135 in this way!

Out of interest @Spongey which filter wheel did you pair with the 268M? There seems to be so many options in the QHY range!

Just a note about the 3.3 reducer...for imaging you only get a limited image circle limited to 1/3" sensors. Any sensors larger than this you get vignetting.

If you go down the route of focal reducers for SCTs, a better option may be to go for the Starizona night owl x0.4 reducers for SC. This has a image circle designed up to 16mm.

Another +1 for the canon lens is that you can use a filter wheel with it.

10 minutes ago, Captain Magenta said:

I know because I own one, and it produces amazing images. But mine is gen 2 or 3 I think, the first IS version, and it’s heavy! Around 4.5kg. I totally love it.

Fantastic to hear that someone is using this lens for imaging. And it’s really great information regards the versions. At 4.5kg it’s still significantly lighter than a RASA8. Do you have any images that you please can share?

Now I’ll have to start looking out for these second hand  

As a fellow Physicist I'm loving this thread keep it going I'm learning a lot from the discussion thank you to all the contributors.

Had to check it out myself, and learned that there are 3 versions of the 400mm f2.8 lens, the latest being the lightest, with the first Canon lens designs featuring new glass materials. "This glass has a comparatively higher refractive index than general low-dispersion glass, and has a low specific gravity. By using the new glass material in the first, large-diameter lens element [which cannot be reduced in size due to the focal length and max aperture requirements], the weight is reduced and spherical and chromatic aberration are suppressed."

4 minutes ago, Nik271 said:

We need to find a lucky person who owns both the RASA 8 and the Canon 400 f2.8 and ask nicely for comparison shoot out 

The main reason the Canon is so expensive is the extra electronics and lens elements for autofocus and image stabilization. I just checked it up: 17 lens elements inside. Wow!

 

Yes the technology of the lens itself is pretty amazing. It would be cool if Canon sold 'for astronomy' rejects with non functional IS or focus

There’s even a photo of the setup similar to what I was thinking of in this post

Phew! Yes just think how much that rig cost to build.

What a fantastic project to work on!

Sorry had to post this picture from the gallery 

1 minute ago, Alien 13 said:

Its this one...https://www.dragonflytelescope.org/

Alan

Wow that is awesome! That is one amazing imaging rig!

Thanks @Alien 13...I have never heard of the dragonfly project...what was that?

@catburglar, yes with my Samyang 135mm I do get sharper images when stopped down slightly, but with the effect of introducing diffraction spikes.

Do you not get a similar effect on the RASA with wires from the camera crossing the optical path?

Thanks @newbie alert
Sure, and in this case what I was wondering is you have two optical systems with the same focal length and a similar aperture.

One is designed and well known as an imaging scope (the RASA). I was wondering if you could get comparable results from the canon?

9 minutes ago, newbie alert said:

Too much emphasis on f ratio..

Is there an issue with discussing f ratio and imaging?

Found some wonderful images over the past few months of users imaging with the RASA 8 scope. And when paired with an APS-C sensor giving amazng widefield shots. If I ever get the time to set up a perminent imaging set up and observatory, I'll probably end up buying a RASA.

Probably a stupid question, but I was wondering would there any comparison if you had a Canon 400mm f/2.8 lens or a similar lens? Its a fraction of the weight (2.8kg vs 7.7kg) and no central obstruction. The usable diameter of the RASA is still larger with an effective diameter of 180mm compared to 142mm and the RASA is optically faster. Probably the reason this is not compared - The price of the Canon lens is significantly more £12,000 new compared to the RASA at £2000.

However, I've been amazed with what I've seen using the Samyand 135mm f/2 lens and just out of curiosity what are your thoughts on the question?

To test it you can use the camera simulator and use any image eg from your previous imaging or even an image file from SGL and ask it to solve it

Glad the fix worked. Don’t know why G17/18 database is needed over H DB but it’ll at least you are making progress

If you are on windows go to programs (where you install and uninstall programs) find the star directory and click uninstalll

I had the same problem and when I installed the g17/g18 database it then worked fine.

Try uninstalling the h databases and install the g database and see if that works.

If this does not work, the other things you can try are increase search radius to 180 degrees and set down sampling to 0 or 1