As has been discussed here almost from the introduction of Celestron's Edge design, That it (I am only speaking to my experience with the C11) is capable of outstanding photos, to the corners of a full frame dslr. or a 52mm circle) BUT the loose primary can drive one to drink trying to get the possible potential performance out of it. Consistently, from one area of the sky to another, with long (over 3-5 min) exposures, or after a meridian flip.
It was a lot of money to get a Planewave CDK 12.5", only justified in my mind (and to my wife) because I intend to be continuing in this hobby for years to come, and I just can't put up any more with the wasted time of less than capable subs. Planewave's recent $2000.00 price drop finally put me "Over the Edge", and I bought one.
After 2 wks now, and with a few good nights to test it out,
Here are my pro and con comments about the switch
Sharper, brighter stars, out to the edge of a full frame (36x24mm) DSLR
Much less affected by main mirror boundary layer thermals.
Very little focus change with temperature change.
Extremely sturdy construction.
Extremely sturdy, and squared up to image plane, adapters.
Generous back focus, except with their custom focal reducer (see below)
No image shift, no matter what.
Use of a guide scope, if you prefer that method of guiding, is limited only by how rigid the mechanical interconnection.
4 point secondary adjustment.
Includes a high resolution, zero image shift, absolute position focuser.
20% larger fov,
1/3 less exposure time.
Good weight to size ratio 47 lbs bare, nearer 60 lbs with the focuser and its controller, and the dew heaters and controller.
Temperature, and mechanical stability of the CDK is many many times better.
At more than twice the price, when both scopes are at their best, the CDK's images are not twice as good.
Somewhat steeper vignette gradient toward the borders of a 52mm circle. Note: this is a first impression/observation, not definitively measured.
Bright stars have spikes, if you don't like such things, or are not used to seeing them.
Price doesn't include the focus controller which you have to buy to operate the focuser.
If you want dew heaters, they should be ordered at the time of purchase, as they are not easily added afterward. The Kit, which includes the controller, is not cheap.
There is no humidity sensor, nor any way to link one to the dew control.
Beware! The optional f5.3 focal reducer, reduces the back focus to 1.8”
High shipping weight, 180lbs. Be prepared to receive!
There is an extra $200 crating charge.
As I look over my list, I must admit, it could give a reader pause about upgrading, but frankly, after wrestling with the Edge for about 5 yrs, it is absolutely wonderful to get top of it's capability photos out of an imaging scope, Every Time. Limited only by my shortcomings, such as, I don't have the sensor quite flat with the image plane yet, and I have the OAG pickoff mirror just a tad too far in.
In other words, it has been worth it for me, and looks like it will be far into the future.
Edited by Ettu, 08 March 2021 - 02:11 PM.