Mercury Transit 9th May 2016

[Joe12345]

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

I would personally prefer putting Baader film over the objectives of the 10x50s. Safer

Flo says that you need about 50* magnification.

[Dragon_Astro]

Totally clouded out for the Venus transit, ended up watching it via some telescope in Hawaii.

fingers crossed for good weather this time, if it's cloudy I'll still get use from the solar film I suppose

[BinocularSky]

Yesterday I showed you why you shouldn't use Eyepiece-fitting Solar Filters. This video shows you two simple and inexpensive ways to safely observe the Sun (including binoculars). 
https://youtu.be/eDZ_nDR1BYk

[acharris77]

Hey all, with the Transit approaching on May 9th I thought I would get myself prepared. I ordered a sheet of Baader Film from FLO and made a filter for my DSLR 300mm Lens and I used some to make a permanently attached Solar Filter to my scope end cap. The results are below.

Thanks for reading.

[Night Hawk]

Ready to go......new badder filter and home made finder scope sun filter.

Just read on the Internet, That you don't need to use the FS for the sun. Just look at the shadow the ota makes on the ground. When the shadow is the smallest you are on target.

[knobby]

Quick note to anyone using the 2" hole in the end cap of their Dob with solar film, please make sure that not only is the film secured really well but tape (at least) the whole cap onto the ota, they're really easily knocked or blown off and not particularly well fitting .

[pblackwell]

Hi LukeSkywatcher,

I can see you do imaging. Can you help me please. My sister dumped her Cannon EOS camera on me (read the manual job).

Can you tell me what settings I should set on my camera in order to try take some pictures of this (ive never used a camera), all advise welcome (lay mans talk though please).

ive booked the day off work so will have time to try and take pictures because of the time the transit takes.

Many thanks

Paul

[pblackwell]

21 hours ago, acharris77 said:

Hey all, with the Transit approaching on May 9th I thought I would get myself prepared. I ordered a sheet of Baader Film from FLO and made a filter for my DSLR 300mm Lens and I used some to make a permanently attached Solar Filter to my scope end cap. The results are below.

Thanks for reading.

Hi, why do you have to do this? I thought you could just cover the entire end of the scope tube, not that end cap? Am I wrong?

[Joe12345]

A bigger filter does give more contrast, but has the obvious disadvantage that it requires more film to make. Both will show the transit well.

[knobby]

On Tuesday, May 03, 2016 at 10:38, michael.h.f.wilkinson said:

Regarding imaging the event, I think I have settled for a dual scope set-up, imaging the sun in Ca-K with the 80mm F/6, and using my ST80 guide scope with Herschel wedge and Solar Continuum filter (plus IR block). The narrow band of the SC filter will remove all chromatic aberrations. I will either swap the ASI174MM from scope to scope, or attach the ASI174MM to the Ca-K set-up, and the ASI224MM to the ST80 WL and use two cameras. I will see if running two instances of FireCapture gets me into trouble. If so, I will just use two laptops

Quite fancy the mono  224 myself ...

 

[LukeSkywatcher]

21 hours ago, pblackwell said:

Hi LukeSkywatcher,

I can see you do imaging. Can you help me please. My sister dumped her Cannon EOS camera on me (read the manual job).

Can you tell me what settings I should set on my camera in order to try take some pictures of this (ive never used a camera), all advise welcome (lay mans talk though please).

ive booked the day off work so will have time to try and take pictures because of the time the transit takes.

Many thanks

Paul

I dont do imaging. I'm the last person to ask about imaging. I'm sure on the day i'll figure out what works and what doesnt IF i want to capture an image. 

[ArmyAirForce]

Does anyone have any thoughts on the length of time to make a video capture against focal lengths, bearing in mind the speed of Mercury, about 1Mer diameter every three minutes?

I thought of using the morning to do Ha and WL full discs, and then concentrate on just the area around Mercury for the rest of the day. But how long is too long?! On Facebook, I've read as short as 10 seconds of video, and any longer Mercury will be elongated, but that surely all depends on focal length and resolution.

So, anyone have any thoughts on this? 

[johnb]

On 04/05/2016 at 20:47, pblackwell said:

Hi, why do you have to do this? I thought you could just cover the entire end of the scope tube, not that end cap? Am I wrong?

this looks straight forward will there be any heat build up, if so turbulence may be an issue and the picture could be awful ?

 

[Stu]

1 hour ago, johnb said:

this looks straight forward will there be any heat build up, if so turbulence may be an issue and the picture could be awful ?

 

The film prevents heat from entering the tube so you should not suffer too badly from tube currents. Solar observing is often a game of trying to catch the times of best seeing which are normally first thing in the morning before the atmosphere has heated up or sometimes later evening. With the transit obviously there is no choice but to observe during the heat of the day so expect the views to be a little wobbly.

In theory using the full aperture gives more resolution and will show more detail. There is, however, a balance to be struck between the largest aperture and the best ability to cut through poor seeing, general wisdom in this area is that around 120mm to 150mm max gives about the best consistent results (in the UK).

[Al.Grant]

I'm off on Monday and at the moment the forecast is looking good (let's hope it's accurate) and planning on giving the Equinox 80 and Quark  a run.

Might also switch over to do some white light.

 

On subject of solar safety ..... here's what happens to the plastic end cap of a Quark when you forget to remove it (too busy chatting whilst setting up).

Thankfully no damage to the Quark ............... but imaging what it could do to an eyeball  !

[PeterW]

Work got a call from a local event in need of an eyepiece, so looks like me, some solar glasses, a sunspotter, 80mm+CaK and a spare eyepiece will be making an appearance. Stops me going down the pub if the clouds come over, but makes it more social. I'll bring some solar images too.. Promise not to photoshop on a small black disk....

 

fingers crossed as always

 

peterW

[knobby]

22 hours ago, ArmyAirForce said:

Does anyone have any thoughtschanges length of time to make a video c apture against focal lengths, bearing in mind the speed of Mercury, about 1Mer diameter every three minutes?

I thought of using the morning to do Ha and WL full discs, and then concentrate on just the area around Mercury for the rest of the day. But how long is too long?! On Facebook, I've read as short as 10 seconds of video, and any longer Mercury will be elongated, but that surely all depends on focal length and resolution.

So, anyone have any thoughts on this? 

I read on solar chat that 10-15 seconds is optimum as the sun cahnges Rapidly

[ArmyAirForce]

It doesn't change that fast!! Mercury will move fairly quickly, but white light is fairly slow changing, and while Ha is a bit more dynamic, that still isn't that fast. A lot will depend on focal length.

I've been having a think about this last night. My ASI120MM is only about 30fps at full sensor, but I can push that up at a 640 x 480 ROI. I like to stack quite a few frames ( several hundred ) to get a nice smooth image, but after a test last night, a 20 second capture only gets about 2000 frames. I usually only stack 15 to 25%.

I think in each capture run I do, I'll record for longer, because if it turns out I can capture for say 30 seconds without elongation, great. It gives me a larger percentage of potentially good frames to stack.

If I need shorter captures, Autostakkert can restrict the chosen stack from frame X to frame Y out of any capture video. So out of a 4000 frame video, AS!2 could select the middle 2000 frames to analyse. This would allow me to choose a 10 or 15 second section of the video where seeing may be better, and choose a percentage of those to stack.

I just have a fear that if I record too short a video, I could end up with noisy images that can't be improved.

[PeterW]

Good point, 15fps will crimp my videos somewhat. Have to play about to see what works best. Forecast isn't going to enable the best chance of lots of images.

 

cheers

 

peter

[ianaiken]

Stephen, we've probably got time to test it out when it starts. I can run at 60fps full resolution. It should be possible to combine data? We're using same res and same scopes at native focal length although some factors may result in slightly different image size. Might be worth a try.

[ArmyAirForce]

I was going native on the Evo 80ED and x2 on the Lunt.

[ianaiken]

80ed is full disc with white light?

 

[ArmyAirForce]

No, that's going to be the other ASI120. I'll do a full disc mosaic in WL in the morning, then do native 600mm FL but 640 x 480px ROI during the transit.

[surfindogg]

What is the best f/l for solar observation?

[Gina]

Weather forecast for here is cloudy all day