Adam J

What exactly was the failure mode? Having taken it apart it's very simple and I don't see why it would fail due to excess weight. They normally strip if you over tighten them though. So I guess if you had to tighten it too hard due to the weight then it might strip the locking bolt.

I think that it's important to remember that thousands of Esprit 100's have been sold so if you ask people for problems your immediately not going to get a balanced audience and it's inevitable there will be some bad examples.

https://www.teleskop-express.de/shop/product_info.php/info/p12285_TS-PHOTON-6--F5-Advanced-Newtonian-Telescope-with-metal-tube.html This is F5 and in my opinion a little better than the Skywatcher equivariant. They do sell an F6 but you would need to change the focuser.

Actually I'll retract that and say to get the 150pds instead as the focus position on the one I liked is not suited to use with a camera. You would need a lower profile focuser. Should leave you enough left over for a baader coma corrector and a collimation tool.

6-8inch F6 Newtonian for galaxies.

I just use sharpcap polar alignment its much cheaper than a ipolar even if you need to buy a guide scope and camera. Also that way you also have a guide scope and camera.

Huum I would think its more the motor and motor controller that would have sufficient torque to and become damaged. The gears themselves are quite substantial and I would find it difficult to imagine that a 5kg payload would cause issues. An ASI533 and Lens of up to aboout 300mm focal length should be easily handled. Adam

The SW has a big range or motion, so no worried with that. For the other two I would check that Iceland is not getting too high. But in general the bigger problems happen close to the equator when you will need a pier extension even with the SW to prevent things from hitting the tripod legs. I would say the 80ED is fine visually but for AP its going to be too heavy for the AZ GTI. Adam

Depends on how heavy your setup is, i am using the skywatcher wedge and it seems to be fine with a 3.5kg payload on it. I can consistently get a "good" polar alignment as measured by sharpcap when using it. Achieving excellent is more of an issue due to backlash in the Altitude adjustment but in my experience there is very little practical benefit going from good to excellent anyhow. The thing to watch out for with the WO wedge is it has a limited range of altitude adjustment that will be an issue if you want to travel to exotic locations with your kit. Adam

It might be that it is allowing the lens element to be made thinner in the case of doping. Such a reduction in thickness would have that effect.

I seem to remember that in the case of doping the effect depends on the type of glass that you add the Lanthanum Nano particles to and in the case of coating it is more like a filter. But if they don't specify how can you tell what they are doing with it? From a quick search in some glasses (at least) it acts to increase refractive index. But its also possible that it has two effects one on refractive index and a second on transmission of violet light. More research required if you want to know the exact answer and you probably need to know what the flint glass is made from too. Adam

Actually it is possible as the miss understanding that most people have in this thread is that Lanthanum is not a type of glass. Lanthanum is a material used to dope or coat the flint and provides an effect similar to a minus violet filter. So in theory it is possible that some have specified this coating and some have not. However, it is more likely that some simply do not mention it and they are all the same as you say. Its just not impossible. Adam

I think that at this stage you need to talk to someone like FLO.

It looks like the 4040 sensor has an issue with calibration across its four sections so is not really a tool for taking nice images, it's more for scientific use. Hence I would go with the QHY.

https://www.firstlightoptics.com/adapters/vixen-60da-focus-wide-adapter-for-canon-eos-cameras.html Should have had the EOS adaptor attached. It must have something on the back?

The first two number of the lens serial number are the year of manufacture.

It tends to lower the temps about 7 degrees or so when imaging continually. That's enough to half dark current but it's nothing like as good as set point cooling.

With the focal length of your scope it needs to be at least 10metres away to work correctly.

Astigmatism that shows in focus is not going to be diffraction limited so if it's in Warranty you should return it. But I would perform a star test first to confirm. You are looking for a oval star test that rotates orientation by 90degrees just either side of focus.

You need to do a star test on a defocused star inside and outside of focus to show between three and five diffraction rings. I suggest an artificial source placed about 10-15meters from the scope. FLO sell an artificial star torch type thing.

Actually that looks more like astigmatism. I.e Maltese cross pattern.

Sound like you are making progress, it will get better and easier every time from here on in.

I'll be surprised if you can find someone with the kl4040 but interested to hear about it from pure curiosity.

I would say it would work. I would say that it will fit just remove two of the four as you say and it should then hold the pinion down with pressure through the mounting bracket.

Can you show a picture of the bottom under the rack and pinion?