I understood that. Not sure there’s enough people willing to committ.
Let’s see what 3.1 and 4.0 produce.
Not sure there’s enough people willing to commit.
I think it would be worth trying.
Bob
I already payed for the license… I will not pay again to get bugs fixed.
If this was an open source software then crowdfunding and bounty hunting would make sense.
With all due respect Chris to your lot of experience in this sort of development, I think you are overestimating the time and effort of fixing the problems with the focus routine by maybe a factor of 100. Too many folks think it requires a major rewrite of the routine to fix the problems. This is totally false. The reason it is false is that the current routine is:
- well designed
- effectively implemented
- produces excellent best focus results
But, the excellent best focus results require excellent viewing conditions. The serious deficiencies are directly related to the fact that it does very bad things when conditions are less than ideal.
The current routine being effective and the best focus routine on the market are well attested to by the numerous users on the forum that continue to tell us the current routine works perfectly for them. It works perfectly for me too, when conditions are good.
So fixing the routine to deal effectively with bad conditions does not require a complete rewrite, it requires a few targeted TWEAKS. I have presented in detail in another post exactly what minor adjustments to the routine will solve the most serious complaints folks have.
The #1 recommendation Ken has already committed to implementing in the current release. This enhancement allows the user to specify a minimum Quality factor that the curve must pass, or some corrective action will occur. I would venture that the hardest part to implement is producing this Quality factor. (see #3 below)
My #2 recommendation would take Ken about 30 minutes to implement. Its effectiveness in fixing the globular problem is unknown, but can only improve the accuracy of all the focus results, not just for globulars.
My #3 recommendation was to change the straight line intersection approach for finding the best focus position to a Quadratic fit( ie. a parabola), which offers major improvements to the accuracy of the best focus result. I estimated this would be the most time consuming enhancement of the three. Sure enough, it took me several hours yesterday to implement the Quadratic fit routine in C++. I will shortly send Ken and Jared my routine, which they should be able to easily plug in to their code in place of the straight line approach. Before doing so I will post here numerous examples of the results it gives compared to the current routine. ie. thorough testing.
A wonderful output of the Quadratic fit is the R factor, which is the correlation coefficient or the perfect measure of how well the focus data points fit the best fit parabolic curve. This is exactly the Quality measure that Ken will need to implement #1.
NOTE: I am also a retired professional software developer with a lot of experience in this sort of development. Well, not totally retired.
Fine, prove me wrong. It will only tae until Monday.
Being pragmatic here… but I think the discussion is going a bit pointless now.
Chris, you might want to re-read the quote you posted. $25 a minute not hour.
Ken, thanks for the update! Glad to hear that you guys are looking into some AF improvements. The improvements mentioned are great… I am curious what you guys might be able to do about speed as well. One of the difficult things about SGP AF is it is very slow, particularly with narrow band. A reliable AF cycle with SGP and narrow band filters currently requires about 15-20 second exposures (at around f/4!!) to get strong enough star signals to avoid noisy curves. It also takes about 7-9 steps, which means the AF routine can take several minutes to complete.
This has been the case with both a Canon 600mm f/4 lens, as well as a Tak FSQ106 f/5 scope. The slow speed of the process is eating into a lot of my imaging time, especially earlier in the evenings when I need to focus once every 15-20 minutes (which is usually about every 2-4 5 or 10 minute frames). Colorado tends to have a very large temperature differential, and can easily go from 90 degree days to 60 degree (or even colder) nights, especially in spring and fall. I’ve had it go from over 90 during the day to low 50s at night in early fall at times, which often forces me to focus fairly often for most of the night.
Efficiency is really the big thing…AF should not just be reliable, but it should also be fast. CMOS cameras with their variable gain and video modes might offer some potential options here. Higher gains with video might allow for some very fast focusing…
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If it could help spur development along, I’d be all for some crowd sourced funding. I like SGP. It’s a one-stop shop for sequence operation, and it is not all that complicated compared to some of the alternatives…and the price is difficult to beat (and free software always comes with the risk of abandonment as well.) I think if the AF issues are resolved, it’ll remain a very solid imaging platform for some time to come.
It should be possible to determine the offset between the luminance and narrow band filters, then focus using the luminance and offset to the NB filter position. The shorter exposures needed by using 100% of the light rather than 5% or less will help a lot.
As for the efficiency vs speed debate what looses more imaging time, having a slow autofocus that works or a fast one that doesn’t?
I have offsets configured already. They generally work, however at very fast f-ratios they often don’t work well enough. I image at f/4 a lot, and will be imaging at f/3.6 and f/3 soon enough here. With faster f-ratios, I find that the tolerances with offsets and backlash, even with backlash compensation, is too tight, and focusing with each narrow band filter gets me visibly sharper results. At slower f-ratios, f/5 or slower, offsets work better. I find that at the faster f-ratios, I still need relatively long exposures (still 15 seconds, in fact 20 seconds if often not quite long enough at f/4 but I make do), and I do need to focus with each filter for best results.
Agreed, especially since FM used to be free.
Jon - I’m not quite sure I follow. Backlash (and compensation) is usually present with any move of the focuser - caused by an offset move in one direction or the final move to the focus position in an AF run.