Deadlake

If you mean the field of view is limited due to the adaptive mirror being used, then yes. You can use multiconjugate adaptive optics to increase the area where the correction is being applied, but it is still small. I think the main issue is that you need a guide start, region mag 12-15 or to use an artificial guide star from a laser being pointed into the sky. Maybe not very practical..

Wiki entry: in order to perform adaptive optics correction, the shape of the incoming wavefronts must be measured as a function of position in the telescope aperture plane. Typically the circular telescope aperture is split up into an array of pixels in a wavefront sensor, either using an array of small lenslets (a Shack–Hartmann wavefront sensor), or using a curvature or pyramid sensor which operates on images of the telescope aperture. The mean wavefront perturbation in each pixel is calculated. This pixelated map of the wavefronts is fed into the deformable mirror and used to correct the wavefront errors introduced by the atmosphere. It is not necessary for the shape or size of the astronomical object to be known – even Solar System objects which are not point-like can be used in a Shack–Hartmann wavefront sensor, and time-varying structure on the surface of the Sun is commonly used for adaptive optics at solar telescopes. The deformable mirror corrects incoming light so that the images appear sharp. Pixel in this case relates to an array of lenselet sensors...

Depends on definition of predictive. Adaptive optics in this case is using a wavefront-sensor to calculate the mean wavefront perturbation in each pixel in the sensor to correct for the atmosphere. Predictive in this sense is a non-random algorithm determining the perturbation to be applied. The atmospheric perturbation being driven by measurement in this case.

If seeing is random then I'd imagine there would be a distribution of errors associated with the waves interaction with the atmosphere before the lights touches the telescopes optics. The error must be predictive in nature otherwise active optics would not work. Which brings be to correctors you've mentions, they have to be active in nature, not something I could modfiy a C11 with.

If I could permanently mount it a reflector would be on my list, given the cost of the mount as well for a 180mm APO to equal a large SCT on goog nights. https://www.cloudynights.com/articles/cat/user-reviews/telescopes/schmidt-cassegrains-scts/a-c14-confronts-an-ap-180-r881 Seeing determines the maximum aperture for visual as you well know: https://www.cloudynights.com/articles/cat/articles/how-to/what-is-the-best-planetary-telescope-r402 The amount error added to an image is culmative, so poor glass will make average seeing poor. We still don’t know how good a lense needs to be to suuport quality of seeing presentat a location. Aperture and quality we could be over buying???

Tak are meant to be a lot cheaper in Japan. Wonder how much a direct import is?

Note: This is a list of what has got stuck, anyways to resolve it. We can all opine about why, if the threads gets too political I'm sure the thread will get shutdown.

I have the ScopeTech Zero mount, I use it with a Vixen SD103S scope which is similar to the Tak you are looking at. One point is that had high magnifications on planets the recovery from using the slow mo controls will introduce to much wobble, takes an age to recovery, I think all mounts of this type will be like this. For its type I think the Zero is the best mount out there. Since you choice of EP’s will not cause that high a magnification you will be fine, but if you choose to push the Tak to its full potential for planets you may need a different mount. I think your choice of EPs means you can get away with the T2 Baader prism, which is half the cost of the 2” version, so if possible stick with that. Use starman’s ep spreadsheet to check the field stop.

I'm sure we have all experienced delays due to pandemic. Now I'm getting an another lot of delays with orders *stuck* between EU and UK. To complete a new telescope scope being built for me requires some tube rings to come in from the EU. These are the only rings which will fit the telescope tube, handle and Losmandy bar, so no other source. At this point this is business to business, no VAT or custom fees are chargeable between EU and UK, but still the items are stuck with no ETA available. I wondered who else is in a similar situation? I've resigned myself to waiting it out, but maybe people with more times on their hands have not? Note: We are where we are, with no change expected.

Just saw this, https://affinity.serif.com/en-us/tutorials/photo/desktop/category/workflows-and-techniques/, amazing Astrophotograph section.

Sorry Wellenform is around 500 EUR, buts that a full strip, rebuild and test for a triplet, I suspect the test is less around 200-300 if memory serves...

It's about 2-300EUR for the optics test to measure the wavefront. Maybe we can find the details on another site like CN??

Less performant EP then, agree value is important and relative. The Vixen HR's are good value compared with Takahashi TOE's that are a 1/3 more in price. 🙂 The SLV's are good value too, but have their limitations, in a larger aperture scope the 2.5 mm would work just fine.

Is a HR a good EP to use, I cannot obtain focus with a Vixen SLV 2.5 on my SD103S but I can get focus on a HR 1.6 with it on the Moon (The SLV will have a Strehl around 0.9, versus 0.999 for the HR centre field). Can you go down market and see what happens using another EP in the spring time? 😃

@mikeDnight isn't there only one answer from someone who started the thread "Is the FC100DZ the best DOUBLET ever made?" 😀

I don't have those.

Shifted to after midnight for clear skies, well lets hope it shifts back to an earlier time.

Would this help, on MTF tab and called modulation? At the same time this scope is near perfect, need to find a lesser scope which is not in the premium class.....

I have something similar but for a 152mm/F8 scope so not what we want. Shame as very good figures...

I suspect up to 30% obstruction will impact the answer. If possible interesting to see what a 11" SCT (like a C11) would do.

I've been on this forums for 7 months and I'm sure @JeremyS has been threatening to buy a Baader diagonal for that time. 😄

I don't see any discussion of optical quality, hence the question.

@vlaiv @alex_stars How would the quality of the scope effect the MTF functions? How would poor seeing (say atmospheric turbulence) in combination with optics quality effect the MTF, presume poor optics would propagate errors introduced by atmospheric turbulence? Thanks

I have the T2 prism, however it seems it will be some time before I find out about the mirror...

This link was of interest to me: https://www.damianpeach.com/simulation.htm The effect of seeing cannot be underestimated. However who are we kidding, if we could we would end up with both scopes a 4-5" Refractor and a large SCT/Reflector for those exceptional nights... Short answer scope of 10-15 cm in size deal well with poor seeing...