Relpet

Hi, Mike.  I took a long look in what passed for daylight today and decided to go for Open Camera instead.  It will change ISO, you can expose up to 5 minutes and focus seems instantly automatic.  Next clear night we'll see how it performs.

Cheers

Peter

Hello, Mick J,

By chance I came across the app myself today and have installed it on a Samsung A10.  This does not take RAW images so may not get the best from the app.  The sample pictures taken by the author of the app are excellent but based on high spec kit; high-end 'phone, Takahashi 'scope, TeleVue EPs etc.  The author hopes to launch a pro version later this year but did you ever get around to using it?  I'd be interested and, though this is your first response, perhaps others will be too.

Cheers

Peter

On 05/01/2020 at 19:08, michael.h.f.wilkinson said:

Some kind of white-balance issue, I would say. 

Thanks again. Michael.  Having checked the camera I found the white balance was set to daylight.  Fiddling in the dark I must have pressed the WB button at some point and accidentally changed the setting.  The moon was clear tonight at 21.00 so I took a few shots at various exposure settings.  None of them showed any colour cast  Best of the bunch attached.  Your advice was also helpful to a member of our local group who had noticed a similar problem so thanks again from both of us.

4 hours ago, michael.h.f.wilkinson said:

Some kind of white-balance issue, I would say. Different optics can change the colour cast of the images. On the other hand, the image with the Newtonian was probably brighter, which may have influenced the auto-white balance of the camera.

Never thought to look at white balance, Michael.  Next time we have a bright moon I'll run through the options and see what works.  I had expected great things from this combination.

Not an expert but I like taking pictures of the moon.  During the last twelve months I've been using a Canon 500D.  I spend half the year in France where I have used various Newtonians with a variety of Baader EPs but prefer to use a 2" 2xPowermate.  Over Christmas I was able to get a second-hand 2" 4xPowerMate which I was looking forward to using with an 80mm TS Photoline refractor.  Everything looked OK on Live View but on the computer all the images came out with a dirty brown cast.  Lunar seeing was excellent.  LP is very low in France but very high in Surrey, a short drive from Crawley/Gatwick.  I can correct the cast to some extent through post-processing but wonder if there is something wrong with my set-up.  This is a combination I have not used before so suspect there may be some inherent fault.  Any ideas, anyone?  Unprocessed comparisons below with France/Newt on the left, UK/Frac on the right.

On 08/11/2019 at 00:54, johninderby said:

Unscrew the inner ring on one side of the filter and you will find two filter elements stacked together inside..Note there are a couple of tiny slots on the inner ring that you can use to unsrew it using a tiny screwdriver. 

Thanks again, John.  I just realised that by removing the ND3 element from the TS filter it would leave me with the green element to use by itself.  So with the Baader ND3 permanently installed in the wedge I can then apply the green filter to the EP if that gives me a clearer view, take it away again if not.  The polarising filter still comes into play in any case.  Thanks again for your patience.

Forecast for  west Hampshire looking quite promising.  This for Micheldever near Winchester.

22 hours ago, Stu said:

FLO will take the ND3.0 as a return if not needed Peter. It does appear the TS is already fitted with one, otherwise to be frank it would be dangerous to use.

Did you say the view improved when you fitted the Baader?

I like the Baader, Stu, and it's now a permanent fixture in the wedge so I'll never forget.  The improvement was the difference between white and green and may have been only apparent as the tests were some days apart.  I haven't used it under a perfectly clear sky yet and being completely new to solar can't guess how good it is or if it should be better.  I look forward to comparisons if Monday works out.

10 hours ago, johninderby said:

TS just say all necessary filters included which as an ND3 is necessary infers that one is included but they should state clearly that one is included to prevent any misunderstanding..

Especially when they told me in writing that it ain't included!  Thanks to all.

22 hours ago, johninderby said:

Unscrew the inner ring on one side of the filter and you will find two filter elements stacked together inside..Note there are a couple of tiny slots on the inner ring that you can use to unsrew it using a tiny screwdriver. There is a pic of this in the thread I linked to but here it is again. Please also note the OP of the thread I linked to asked TS about it and they confirmed there was an ND filter. Did you ask if there was a seperate ND filter which there isn’t as it is a combined filter.

Thanks for putting me right about that, John.  I managed to unscrew it with a toothpick.  This was the question I asked TS.

"I believe that the TS-Optics solar prism, unlike some other brands, does not incorporate an ND3 filter within the unit.  A friend has recommended I buy one so I have ordered a Baader filter from a UK supplier. Where in the sequence should I fit an ND3 filter please?"

Their reply was:

"yes you are right is not incorporated. a polarizer is provided, but you can use also a ND one, as you prefer. the sequence is the same."

So, it seems to me TS are missing a trick as it seems their wedge is even better value than I thought.

9 hours ago, Rob Sellent said:

Just emphasising what @Stuhas already said. The Herschel Wedge is only suitable for fracs and the ND 3.0 filter is imperatively necessary - it is not a choice. A polarising filter to varying the remaining light output is optional, so too a Continuum filter. But NOT the ND 3.

 

That's why I bought the Baader ND3, Rob,  after reading extensively and taking previous advice from Stu and others.  As it is it looks like another significant investment to meet the needs of a special event will fail to pay a dividend.  I sent an email to Teleskop-Express asking them to confirm that an ND3 filter was not incorporated in their package - which they did.

9 hours ago, johninderby said:

There certainly is an ND3 filter. Take apart the double stacked filter if you don’t beleive me.

I don't want to quarrel over this but attached is a picture. of the narrowband filter.  Short of taking a bacon slicer to it there's no way I can see that there are two separate elements.

2 hours ago, johninderby said:

The TS wedge comes with an ND3 filter preinstalled. It’s double stacked with the continuum filter in a single filter cell. You can remove this double stacked filter and just use a plain ND3 filter if ypu don’t like the green image.

This is the description by TS:  There's no mention of the ND3

The advantages of the TS-Optics 1.25" Solar wedge:

• Particularly high-quality surfaces for very high contrast
• Enclosed housing with integrated light trap - no escaping stray light
• Cooling fins for quick removal of the heat
• 1.25" polarising dilter for screwing into the eyepiece or into the filter for continous adjustment of the brightness without without additional colouring.
• 1.25" narrow band interference filter dor significantly enhancing the contrast of the solar surface. Especially faculae regions are shown better. The filter has a bandwidth of approximately 40 nm and a peak at 540 nm. Now sun observation is possible with fast Fraunhofer refractors, as the chromatic aberration is removed.
• Especially faculae regions are shown better. The filter has a bandwidth of approximately 40 nm and a peak at 540 nm. Now sun observation is possible with fast Fraunhofer refractors, as the chromatic aberration is removed.

I missed the last Transit of Mercury in 2016 and as I shall be 93 when the next one comes around I thought I'd make an investment  for this year's.  Never having done any solar observing a fair amount of research was needed and it was quite clear I could spend either no more than two week's state pension or a couple of years' worth.  As I was going to be in England for the transit and being very familiar with the normal ghastly weather in an English November the more modest amount seemed appropriate.  After looking at various Herschel wedges the TS-Optics seemed the best value for what might be a one-off experience.  It seemed similar in design to the Lunt but came with polarising and narrowband filters, extra costs with the Lunt.  On the other hand the Lunt came with a ND3 filter pre-installed.  Looking further into this it seemed the ND3 filter in the Lunt could only be removed by voiding the warranty and breaking some kind of seal.

So, I bought the TS-Optics job to see how I got on with it just using the supplied filters.  There was a bit of sunshine around the day after it arrived so taking all the necessary precautions that I had read about (and taken to heart) I lined up my TS-Optics 80mm Photoline refractor using a variety of eyepieces and both filters.  Seeing a green sun was a bit unnerving but I was getting sharp focus down to 5mm and the polarising filter did the job of adjusting the brightness level by simple rotation of the eyepiece.

However, further reading suggested that the ND3 filter would improve the observing experience so I bought the Baader filter from FLO.  The eyepiece holder is removable from the TS wedge so I was able to screw the filter into the interior of the eyepiece holder effectively between the prism and the eyepiece itself.  So, it can either be a permanent fixture in the wedge or removable if I want to use it elsewhere.

Today the sun shone again, albeit through some thin haze, so I was able to try  the new combination.  Now I know what they mean by white light.  It was a revelation.  I'm not experienced enough to know what perfect conditions are like for solar observing but I have high hopes now when conditions are better.  Focusing down to 3.5mm using a SW7mm with a 2xBarlow suggested that when there is something to see like sunspots I stand a good chance.  Sadly in south-east England the chances of seeing the Transit of Mercury next Monday seem ever more remote.  Thanks for reading.

10 hours ago, Stu said:

Hi Peter,

I'm off on 11th as are some of the other WAG gang, so hopefully we can meet up and find somewhere clear to observe this. Only thing to do is keep and eye on Sat24 and make a call on the day I think.

Stu

I'll be hot to trot, Stu.

22 hours ago, Davey-T said:

You can't take much notice of weather forecasts that far ahead, they have trouble getting it right for a few hours ahead 😂

Dave

A respected forecaster said recently that their 10 day forecast was as accurate now as their 24 hour forecast was a few decades ago.  Fingers crossed.  A 30 minute break in the cloud will do me.

Not much chance in Dorking judging by the latest forecast.  Is there any place in England that has a positively sunny outlook for 11th November, please?  I'd quite like to see this transit as I'll either be aged 93 or fresh stardust when the next one comes around.

A simple hacksaw did the job for me.  Mine was painted black so rounded off the new sharp edges with a flat file then painted over the raw end with black paint.  I wanted to fit a non-standard OTA on a Celestron 4se mount and the spare dovetail to hand wouldn't permit full movement.  I've still got the waste end somewhere "in case it comes in handy".

I'm lucky enough to be able to spend half the year in south-west France.  It was there four or five years ago I first took an interest in astronomy because the skies on a clear night revealed more stars than I had ever seen from  our permanent home in a part of Surrey totally overwhelmed by light pollution.

I made some fairly big investments in telescopes and eyepieces and have had a lot of pleasure from observing but like many others made a start on imaging, mainly the moon with a DSLR shooting through suitable EPs and a 12" Dob.

Having seen so many wonderful pictures of the Milky Way taken by amateurs and with a 360 degree Bortle 3 site just a few kms up the hills behind me I thought I had to give it a go.  I bought a f2.8 wide-angle Rokinon lens for my Canon 500D, a Manfrotto head and a decent tripod but 20 seconds was about the longest exposure I could get without star trailing.  Clearly I needed a tracking system but the prospect of hauling my AVX mount, power pack and telescope with camera mount up the hill was too daunting.  A German friend introduced me to his clockwork Omegon LX2 Minitracker and after a few trial shots I was convinced this was the solution.

Soon after I found Omegon had released the LX3 in Europe.  This has an improved mechanism but also a greatly improved polar finder over the LX2.

Needless to say the skies clouded over the day it arrived so some three weeks later finally I got a chance to use it.

The manual, which you have to download, is straightforward and once everything is attached shooting is utterly straightforward.  I bought the version which includes the Omegon ballhead and I found that at some angles the ballhead could not keep the camera in position but 90% of the time the camera was rock steady.  The clockwork timer will run for an hour on a single winding.

I've been able to try it on two nights recently, once from my yard and once from the hilltop.  I'm still having a lot to learn about best aperture, ISO and timing combinations, not to mention post-processing but the attached pictures might give anyone else with an interest in Milky Way imaging some idea of the effectiveness of this mechanical rather than electrical device.  I believe I captured the Andromeda galaxy halfway down the left of one picture though I'm happy to be corrected on that.  The picture of the crescent moon and Jupiter setting, vastly over-exposed, is thrown in for fun.  Except for that one the others were all two-minute exposures at ISO 1600 at f4.

12 hours ago, knobby said:

🙂 sorry ! SAM = Star adventurer mini, about the size of a Rubiks cube, fitted in camera bag in the gap where a lens usually fitted.

Cheers, Knobby.  I must say I like the look of Nigella's results with the clockwork job.

On 02/08/2019 at 00:32, Nigella Bryant said:

Yeah, I use one while on holiday's. Great little clockwork mount. I've used up to a 300mm telephoto lens with modded Canon 1000d. Image of orion taken with above and scutum star cloud with 80mm lens. 

 

 

That's truly impressive, Nigella.  Thank you - and welcome to SGL.

12 hours ago, knobby said:

Looks interesting and very compact ... I thought my SAM was small !

Pardon my ignorance, Knobby.  In my RAF days a SAM was a Surface to Air Missile.

As an alternative I've been guided to this

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p11058_Omegon-Montierung-Mini-Track-LX2-SET-mit-stabilem-Kugelkopf-fuer-mobile-Astrofotografie.html

which  has the advantage of being clockwork and got a good workout in Sky at Night magazine last year.  A German friend has used one successfully.  Hmmm...

Has anyone here used one of these, please?

https://www.moveshootmove.com/

If so I'd be grateful for an opinion.  There are some glowing reviews on YouTube but they seem to be sponsored by the maker.

Thanks, Alan,

I need to do some more work with the manual.  I shot some RAW images of the moon this evening and found  each image was mirrored with a JPEG, which seems a bit unnecessary.  Pics weren't brilliant on first sight but will persevere on the next clearer night. Your lucid advice is greatly appreciated.

Cheers

Peter

4 hours ago, symmetal said:

Yes, that's an example of image posterization due to having an insufficient image bit depth. I assume you used the jpeg images from the camera which have a bit depth of only 8 bits rather than using the raw images from the camera which have a bit depth of 14 bits. An 8 bit mono image can only display 256 (2^8) distinct grey levels while a 14 bit image can display 16384 (2^14) distinct grey levels. A smooth brightness gradient will therefore show as a series of grey bands in the 8 bit image.

Stretching the image will make the effect more noticeable as the brightness difference between the bands will increase. Also, it appears the image has been sharpened, as the edges between the bands have been accentuated making them even more evident.

Alan

That's such a clear explanation of what must, to more experienced imagers, seem an obvious error that it's even overcome my disappointment.  I've been told several times to shoot in RAW and I'm about to change the default setting this instant.  Thanks, Alan, and to all who replied.