Freddie

Are you thinking Quark or a dedicated solar scope? Are you more interested in close up of spots and proms or wider full diameter of the sun? Budget?

Looking good Neil. Nice close up. Not had a chance to image that big spot.

Nice, that spot has developed nicely.

Thanks Pete. Yes you need to have the seeing on your side in this game.

Nice, shame there wasn’t a bit more activity for you 8 years on.

Nice set of images there and a lovely ani.

Yes, nice image and a great looking location.

As you say it would be hard to relate to actual solar imaging, there seems to be no point in doing the experiment as what I want to achieve is the best quality solar image I can, not a picture of a wall. Anyway, thanks for your input but I think it’s time for me to move on.

Doesn’t look like we are going to get any images that show higher gain doesn’t produce poorer quality images but never mind. Like Neil, I absolutely respect Vlaiv’s knowledge on the theory of this and many other subjects as shown by his numerous posts across the forum. In this case however, I’m happy that I didn’t just follow theory and just maybe Neil and I have a better knowledge on what it takes to get out there, get the data and produce a high resolution image. Enjoyed the discussion but on that note I am off to make a sandwich for lunch and yes it will contain the left over chicken from last night!!!!

I prefer using my Baader green filter than my continuum. Have you tried your green filter that I assume you still have from your planetary RGB set?

Yes. As I said earlier though, maybe the talk of increased gain and increased noise isn’t helping in this discussion. You may well be right that increased gain doesn’t increase noise (that being noise by the true scientific definition) but as an imager I don’t really care about the theory of gain and noise, what I care about is what it takes in reality to produce the best quality images and I know from actually being out there trying different settings, getting the data and producing images is that increasing gain (even at the same exposure) produces poorer quality images because of something that looks like noise. The discussion about the theory of this is all very interesting but I would still be keen to see your solar images that show that increased gain doesn’t produce a poorer quality image in an actual image rather than a theoretical one. Maybe in addition to this imaging section we need a new section where people can post theoretical images 😀

Thanks for the comments Vlaiv and I wouldn’t want to try and convince you that you are wrong. All I know from my hands on experience of actually producing images is that the theory is all well and good sitting inside at a keyboard but when it comes to actually producing images, experimentation over the years has shown that increased gain, ends up with poorer quality images. Maybe you have produced some actual solar images that you can post up that show the opposite.

Looking good Neil. That last one is certainly showing potential. I wish I could get my setup to stay in focus for as long as a few seconds at a time!!! I think your expectations of daytime seeing at that kind of image scale are a touch optimistic.

Thanks for your kind comments guys.

Thanks for your comments everyone. Appreciated. Damian, full 152mm at all times for me. Only calibration I use is flats. Taken out of focus on a bland area of the surface. Vlaiv, thanks for your full explanation of the theory on this. Over the years that I have been imaging at high resolution in Ha and WL my real life experience of having tested various settings is that my low gain low stack count approach produces the best quality images. Maybe there are just too many variables at play to just rely on theory rather than practical experience for solar imaging and I know Neil produces absolute top quality planetary images so I’ll be sticking with low gain for now. Always open to improve things though so if you can show some of your own high resolution Ha and WL images (particularly high resolution WL as that is my main interest in solar) that show the improved quality of your theory I would be very interested. Edit: A thought whilst I was eating my dinner. Maybe we should be talking about settings that produce the best final image rather than specifically gain producing noise? I guess it is possible that increased gain doesn’t produce increased noise when noise is defined by the strict scientific term. What I do know though is that increased gain produces a lower quality final image because of something that looks like noise and that was the point of the discussion. So rather than hold back any future discussion about the effects of gain by referring to noise, we should just be discussing in terms of gain resulting in poorer quality images and therefore low gain is advantageous, be it because of actual as per the scientific term noise or just something that appears in the image at higher gain that looks like noise and you can’t just rely on theory, you have to get out in the field (or back garden in my case) Just a thought as I guess in the imaging section we are all just trying to produce the best images we can. And for those that are wondering, it was roast chicken!!!!

Nice. Good to see you out for the first time. Do you think you may have been slightly off band with the Quark?

Captured early afternoon of 26th.

Couple of nice looking shots there Pete. Great work.

Thanks for the comments everyone. Appreciated.

Thanks for your comment Kon. Appreciated.

Thanks Neil. In terms of exposure, I agree that short exposures help in poorer seeing conditions if your can reduce from a reasonably long exposure but my experience is that when you are already down at 2ms, reducing it really doesn't make any difference.

For me, the key is that daytime seeing is rubbish so you need to do everything possible to overcome that. Having a go at WL imaging is good to get your eye in as it is so much harder than Ha. One thing that isn’t lacking in solar is signal given the sun is so bright so I set gain as low as possible i.e. very low single digit to keep the noise down. Some would say that you need some gain to reduce read noise but my real world experience is that gain may reduce read noise but the overall addition of noise with gain swamps the reduction in read noise, so low gain for me. I also leave gamma well alone. I believe you said in a recent post that you were adjusting gamma during capture. The problem with that is that the data is lost for ever that way but if you leave gamma alone during capture you can always make adjustments in post processing. I aim for a histo about 60% which for me means an exposure of about 2ms. The point of the low gain and hence noise is that it allows me to keep the number of frames in the stack as low as possible. I would never go above 100 and often use as few as 50. Given the seeing is usually so bad, having only a few frames in the stack keeps the image sharp. I use alignment size 56 typically which gives around 1,000 alignment points and have not seen any benefits from multi. I then take the stack into ImPPG and try not to go too mad on the sharpening. Using only the absolute best frames means that it shouldn’t need much sharpening anyway. It’s then into PS where I adjust the overall brightness with levels. Take care with the black point as it is easy to lose detail in the umbra by setting the black point too high which just turns the whole umbra region black. I then use curves to add contrast to the whole image but again keep an eye on the umbra. You can protect the detail in the umbra by pinning the curve at the bottom or by using a layer for the umbra and a layer for the rest of the surface. I never use any noise reduction. For me, if you have to use noise reduction, it just means you have been too aggressive in ImPPG sharpening. I have no doubt that others will use different methods to great effect and may disagree with my approach but this is what I do for what it’s worth.

Nice ani there. Good work. Shame the seeing so rarely plays game.

Nice image there and can I just say, so sorry to hear of your recent news, my thoughts are with you.

Thanks for the comments guys. Much appreciated. I'll gather my thoughts and post up some notes on capture and processing later.