Alien 13

I would have thought that scaling one of these up would be better 😂

Alan

Late to the party but this is mine.. Its a combination of an aluminium phone mount and some Smallrig bits.

As mentioned I would also get a BT remote, I am using a Zodiac one which has very low latency..

Alan

The rocket is by far the best option, nice and slow when the air is thick then accelerating into a diminishing atmosphere however as a large proportion of the fuel is used getting it moving to a few hundred MPH then perhaps they need a gravity assisted  kick start similar to a roller coaster..

Alan

I saw this on the BBC Click program.

https://www.bbc.co.uk/iplayer/episode/m00142dw/click-swingin-satellites

I have often wondered if the energy required to launch this way or by Cannon or by climbing a sky tether would be the same as using a rocket anyway.

Alan

18 minutes ago, saac said:

I must admit Allan that prior to watching it I would never have really thought about it like that. Then again I suppose when we talk about "cross talk" among data cables (ethernet etc) then that is the same principle at work.  I guess also something similar at play when you hold say a TV aerial cable you can affect the signal - maybe !

I wonder if in your previous life in Avionics you must have come across the wonderfully named Time Domain Reflectometer (I think that was its name).  The avionics technicians at Kinloss were trying to educate me on how they could use it to chase down breaks in the Nimrod's wiring loom.  As they explained it, it all sounded oh so plausible and fine but walking away it just confirmed that the world of electronics, avionics in particular, was truly a black art to me !

Jim 

Cable design can be a black art and "cross talk" can exist along a single cable, reflections from an un terminated or incorrectly terminated connection are common too.... It gets spookier when dealing with microwave components 😀

Alan

5 minutes ago, Macavity said:

I hadn't come across that (name) - I shall watch it. "Good stuff" whatever!

Here it is but lots of others in the series..

Alan

13 minutes ago, saac said:

Students are generally surprised to find that the rate of electron drift is quite low - our teaching model of current as a flow of  electrons (or holes for that matter) is so incomplete on many levels but still useful. I do like the Veratsium video on energy  transmission taking place outside of the conductor. 

Jim 

 

 

That Veratsium video is a good watch, it sort of made sense why good audio cables are not just about the conductor type but also the insulator and overall construction.

Alan

Enclosures for my projects has always been a problem for me and have used the "rack" system components many times, more recently I use the Chinese made boxes (sometimes not a cheap option) so have to design kit to fit a specific size. Have even had custom made enclosures milled from a block of aluminium for my "special" audio projects.

The other issue I have is adding fascia details without having to have panels sent out for CNC machining etc.

Alan 

I would argue that the opposite is sometimes true, for example its mobile phones that are pushing the boundaries of CMOS camera development. Its also the case that mobile phones and mass market tech in general that have increased the use of robotic manufacturing facilities etc.

Alan 

I have never liked the term "better" when discussing mounts, different with differing capabilities and limitations would be better. 

A HEQ5 would be less than useless if you wanted to take a trip abroad to image some milky way shots for instance with a DSLR and wide Samyang lens for example, the milky way shot can still be classed as serious AP and might even win you a APOTY or similar.

I would guess anyone "serious" about AP will have an HEQ5 type mount but also a "star tracker" and a decent photo tripod too.

Alan

I do a lot of prototyping and use a combination of vero board of the FR4 kind (more expensive but far better) and simple hand drawn designs using Humbrol Enamel as the etch resist, I do use a drawing package to produce a template though.

Alan

1 hour ago, ollypenrice said:

Well, I got there in the end but I'm not really sure how. I tried to make one change at once but somehow lost track when I decided to follow an internet tutorial on Photoshop for photography. (What else is it for? ) I switched to Adobe RGB colourspace everywhere I could find, ditching N. America General Purpose 2 which one expert dismissed as 'pretty useless' and went for Custom-Adobe RGB. In View, I also went for Proof Setup- Custom-Adobe RGB again. Proof Colours is unchecked. I'm convinced I'd tried all this before and still had pinkish-red for white but now I have good agreement with my copy of CS3. 

I also received a Datacolor SpiderX (miraculously delivered next day, which is good for where I live) and calibrated my screen. It was clearly about right before because it didn't change by much, but it may affect printing more dramatically. I'm dithering over a good photoprinter now that the ink-tank printers don't hold you to ransom over cartridge prices.)

Thanks Tom, Alan and Ciaran for your input.

Olly

Good to hear Olly, those Spyders are a must for anyone serious about photography, am still amazed that even my laptop screen is spot on for photo editing etc even with its very limited colour/luminance range.

Alan

An ideal site for me would be all concrete or granite, have red LEDS embedded in the floor, have power points, have good WIFI, have security with a gated entrance, have toilets, have a burger van or similar, have access to a warm room 😀

Alan

I think a handle is vital with any scope if you are trying to maneuver it into position single handed while adjusting a clamp etc...

I even have a handle on my DSLR to prevent slips when mounting it to a tripod, I almost lost it once..

Alan

I cant offer any practical advice but know only to well the minefield that is "colour space", my only suggestion that is a last resort option is to log all your settings on both versions of PS and do a "reset to defaults" to see if that fixes the issue.

Alan

10 hours ago, vlaiv said:

When we are at it, does anyone have sensible idea of how to provide

3/8" connection on bottom and top side of 3d printed part that is load bearing?

Would simple 3/8" insert be enough to attach tracker to tripod on bottom and carry ball head and camera on top?

I would be tempted to bond/screw the base and top plate to something like this lots of similar designs available too.

Alan

There is a lot of glass in a lens compared to a scope although a true APO scope can have 5 or 6 elements but the important bit is the quality of the coatings that help to reduce artifacts and improve transmissibility so going on f/ratio alone is not the complete answer as mentioned earlier (one reason video lenses use T stops rather than f stops).

The choice should realy be made by the target type you want to image and your camera sensor specifications not forgetting of course how portable you want the whole setup to be.

Alan

Watching with interest as my Son has recently acquired a 3D printer and asks me if I want anything printed? 

Have the DSLR/Lens combo covered with my EQ3-2 but would like something much more compact without going the SA route. I have even thought about a tiny Star Tracker for a mobile phone as these are beginning to get reasonable Milky Way shots even now and will only get better.

Alan

Very nice, one of the best full moon images I have seen.

Alan

15 minutes ago, Rusted said:

That reads as if your were personally responsible for holding back military progress.
 

It does read that way doesn't it 😃 I did push for change though and a lot of commercial products got incorporated into systems like the Panny Toughbook (must have bought hundreds of those). The biggest change was when companies like Samsung entered the game..

Alan

3 hours ago, Swoop1 said:

Isn't JWST 'Old' technology?

My understanding of this type of project is that there is a cut off time during development when they say "No more upgrades- we build to this spec" otherwise they would never get it finished because they keep trying to shoe horn in the latest release of widget.

Pretty much the same as most military projects I worked on, you start with cutting edge tech but by the time the R&D is finished and manufacturing completed it can be 10 years out of date, then you have an in-service time of up to 20 years. Thankfully things started changing when I left the industry and the need to re-invent the wheel each time has gone, often specialist companies can supply whats required off the shelf now even if it means extra testing etc.

Alan 

31 minutes ago, powerlord said:

most zooms are not very good for stars. I think this 40 page thread is testament to the samyang 135 being a good buy. BUT, you don't need to spend 400 quid on a samyang. I'm not a nikon man, but if you get yourself a vintage prime lens from ebay - 135-200 or so for 30 quid, chance are good that it will work quite well too. And with the savings, get yourself an L-extreme 2" and screw it over the end.

that'd be my advice anyhoo.

stu

Good advice but unfortunately very few if any old lenses will work with Nikon due to backfocus issues..

Alan

I think your PC and monitor needs a calibration, I use a Spyder 5 and get perfect colour/greyscale colour space even on my laptop.

Alan

Canon R6 camera with the 400mm f/2.8 lens, with batteries and adapter that leaves me around 4K for the mount but it would need to be ultra lightweight so not sure whats available 😃

Alan

8 minutes ago, tomato said:

With regard to the lack of cameras, it is an extremely (and expensive) serious scientific endeavour, not a social media exercise, so I can live without camera feeds.

I would rather see what the JWST can discover about the very early universe and the nature of exoplanets rather than it take selfies. We can let Starlink take care of that.😉

2 minutes ago, Ian McCallum said:

Indeed, the JWST is designed to look outwards, not have cameras strapped to it to take selfies!👍

Agreed to some extent but a camera is a wonderful diagnostic tool, like the old saying "a picture is worth a thousand lines of code" if a problem needs fixing.

Alan