First serious AP attempt with a Sony A7 on M42

[Adreneline]

This is my first serious attempt at using my basic Sony A7 for AP on a WO-ZS71 mounted on the NEQ6.

Individual frames were captured using Sony's own software and that is where I ran into problems - it has a mind of its own!

Focusing using a Bahtinov Mask and Live View on the laptop seemed to work pretty well. The software then allowed me to take 9 x 10s and 4 x 30s exposures despite my best efforts to take 20 of each - it was not going to play ball.

These 13 images were stacked in DSS without any calibration frames (I took flats but I judged them not fit for purpose and I wasn't too impressed with my Darks either!). ABE was applied in PI along with MLT noise reduction. The image was cloned and the original incrementally stetched with HistogramTransofrmation and the clone with Arcsinh stretch. The two resulting images were then Mask Layered in Photoshop, levels applied and a small amount of additional noise reduction.

I think this A7 has some potential providing I can sort the Remote software and get myself some decent calibration frames.

All comments and suggestions greatfully received.

Thanks for looking.

Adrian

[AbsolutelyN]

Nice. I've found Sony cameras to be excellent for astro. I also found the imaging edge app to be quite good for remote though it's a shame apps such as sequence generator pro don't support Sony. Let's hope Sony make it possible for such apps to support their cameras.
 

[Adreneline]

8 minutes ago, AbsolutelyN said:

I also found the imaging edge app to be quite good for remote

Thanks for the comments. I've downloaded and installed Remote/Viewer/Edit but it is Remote that is giving me a hard time! I can set the exposure length and set the interval timer to say 20 exposures with 10s intervals and it will even tell me has taken "20 of 20" but when I look it can have taken any random number of frames between one and twenty; it's never the same twice. I must be me doing something wrong.

Thanks again.

[AbsolutelyN]

Bulb shooting was weird. You had to set it in two places via menus and very importantly set to bulb which was only an option once bulb shooting was enabled (and you may need to be in manual mode). Many times I'd set it on a sequence and it would space out the shots correctly but because it was not in bulb mode in the main camera control panel it would be using the exposure set there. It always took the rightr number of images though - I'd need to boot intop the app to check but it won't load up.

That's the main issue I had - issues with connecting. If it didn't work first time I seem to have to reboot to get it connect. I've darks running and can't reboot right now otherwise I'd hack to refresh my memory of how it works.

Another good option is a cheap interverlometer. Also if you get the grip (doesn't need to be the sony grip) you can double battery time. Mine is the A7R3 so on the bigger Z battery - I could have it running all night and still have battery left in the morning. 

Make sure you have the latest version of the remote software as I think latest version had improvements to bulb. Still needs a lot of improving to make more user friendly!

[cuivenion]

Apparently a lot of the Sony A series camera's have a noise reduction function that removes stars, dubbed 'star eater'. This function can't be turned off and kicks in on exposures of 4-30 seconds depending on the model and firmware. This is why they're not used more often by astrophotographers.

[cuivenion]

http://www.markshelley.co.uk/Astronomy/SonyA7S/sonystareater.html

[Adreneline]

38 minutes ago, cuivenion said:

Apparently a lot of the Sony A series camera's have a noise reduction function that removes stars, dubbed 'star eater'.

My understanding was that this was a problem only with the A7S; I don't know whether it applies to the MkI, II and III versions.

Mine is the bog standard A7 - no frills - first generation.

I read this thread:

which includes this by Mark:

"In Bulb mode, the Sony firmware automatically implements an algorithm to reduce hot pixel noise, which appears to be more or less identical to the original infamous Nikon "star eater" algorithm.  For any semi-scientific instrumentation e.g. measurements of variable star intensities, star magnitudes, star profiles and FWHM this totally rules out Bulb mode.  For producing pretty pictures of the universe (my own main interest) "star eater" does not seem to matter much - see my analysis here: http://www.dpreview.com/forums/post/55734616  As a workaround 30sec exposures can be used instead of Bulb mode.  Read noise at ISO 2000 and above is so low that 30sec exposures become quite practicable in most circumstances." 

from which I concluded the so called "star eater" wasn't really going to be a show stopper for me as I was only looking to produce "pretty pictures of the universe".

57 minutes ago, AbsolutelyN said:

Another good option is a cheap interverlometer.

Which intervelometer did you use? Also it is not clear to me where it gets plugged in! I know I must be missing something.

Thanks for all the comments.

Adrian

[cuivenion]

Apparentaly you can do 30s non bulb exposures without star eater kicking in then. As well as removing stars it can punch holes in them making them look defocused. But if you're getting good results more power to you.

[AbsolutelyN]

I've only used 3rd generation of a Sony camera so no idea about star eating. Not had any problems with my A7R3. 

I used the interverlometer that came with the grip I got - its a wireless remote. Obviously you may need something specific for first generation camera.
https://www.amazon.co.uk/gp/product/B078XTZ278/ref=oh_aui_search_asin_title?ie=UTF8&psc=1