focus help for solar

[Taipan]

Using a Lunt 50 and a ZWO ASI 178mm.
What program do you use when you filming?
And because its so hard to se the screen on the computer when you are out in the syn. Is there som focus aid function for the sun??
Tried Firecapture but have problems with frames not being saved. And just downloaded Sharpcap to try it out.
/Mattias

[marktownley]

Hi Mattias, I use Firecapture. You can put the laptop in a cardboard box to shield it from the sun light.

[robert]

Focus on the limb to start with.
Motor focus helps and as Mark says shade the laptop.
I use firecapture
Robert

[Starry Jack]

Use a brimmed hat and a light shroud as well. Get some fabric from a fabric store that is meant to out in windows to block light and attach it to your cardboard box and blanket it over your head. I sometimes also use a dark plastic bin which doubles as a storage transport bin as well for the Astro gear.

[PDB]

Hi Mattias,

Most of the capture programs (FireCapture, Genika and probably also SharpCap) have built-in focus aids. However never had very good results with it. What gives me very good results is Genika with the autofocus feature. But that requires a solid focuser with motor (Needs an absolute focuser) That with a ls50 and standard focuser not possible.

However there is a "trick" that you can use for manual focusing. Place the Sun so in fov that you have also the limb (or full disc) in view. Make sure your you don't over expose. Histogram should not touch the right side. Then take a look at the left side of the histogram. You will see a "dip" in the histogram.
When you focus, that dip will go up/down. Try to get it as low as possible, then you have reached correct focus.

Regards,

Paul

[Rusted]

Shade boxes have been mentioned by you can make the box even better.
You need a tall, deep box [front to back] to exclude light but not too small.
I tried many sizes of free boxes from the supermarket stack and was surprised how big a box I needed.
You still need to reach the keyboard comfortably to type and to see the screen easily without ducking own.
You must also have several cables plugged into the laptop.
Inexpensive 90°elbow cables, plug or adapters can help to avoid making holes in the box for the cables.
Where they are impossible to reach to plug in or to pull out.

I use SharpCap but focus manually using its Zoom feature at 150%.
Getting a sharp edge to the sun's image is far easier than looking for subtle surface features.

I always wear a dark baseball cap with a black peak and black clothing while imaging.
Pale clothing will be reflected straight back off the screen into your eyes.
Making it difficult to see anything at all.

Even black clothing will reflect if you are in direct sunshine.
It is far easier to work in shade if you can. Far more comfortable as well.
Put the telescope out in the sun but sit in the shade. With your laptop on a small table or similar.
The shadow of a building, under a balcony, or in the shadow of a hedge, bush or tree can all help.
Avoid any bright reflections from surfaces behind you. They will light up the screen and reduce contrast.

You can use make a small dark cover using lightweight tarpaulins and tent poles for shade.
Or even a dark, cloth, sun canopy to shade you.
We have a big, "ridge tent flysheet" type of sunshade on very tall, tent poles.
Ideal for shade from the hot sun when working out of doors.
It doesn't have to be very big to provide enough shade just for you though.
Some lightweight tarpaulins are black on the inside and dark green the other.
Ideal for a making a small sun screen.

A longer USB3 camera cable may be necessary. No need for a special ZWO.
I use a 2m long USB3 cable on my ZWO ASI174MM with no problems at all.

I hardly ever use my ASUS 15.6" laptop screen any more. Far too shiny and far too small for imaging.
So I use a 25" computer monitor in the darkness of my observatory dome.
The black interior of my dome kills reflected light and shades me from the hot and blinding sunshine.
While the telescope can still see out of the observation slit. An ideal but rather expensive option.