Mandy D

I'm not even sure how to pronounce "electrosucution", but I do know how to spell Van de Graaff. I got hooked up to one in school to make my hair stand on end! It tingled a tiny bit! 🙂🙃🙂

Technically, electrocution (c.f. execution) means death by electric shock! Although, thanks to popular culture, today it gets used interchangeably with electric shock and even dictionaries are now including such definitions. This does not make it correct though.

Nikon's ISO performance is very model dependent. D3200 - I don't like shooting above ISO-100 if I can help it. D800 is excellent up to ISO-400, very, very good at ISO-800 and very good at ISO-1600. D7200 gives lower noise than D3200, but I haven't compared it with the other two properly. Ken Rockwell's camera reviews show the ISO performance of most cameras and I recall that he did a comparison between the D800 and some cameras from other manufacturers, with the D800 leading the pack all the way through.

Electrocutions (plural) and one death? Does nobody understand English, any more?

@Littleguy80 I like that version. It has a real 3D look and feel to it. I almost feel it is like the view from a space probe passing the Moon and heading to distant Venus.

Nooooooooooooo!!! We cannot allow this kind of thinking in here! I'm currently losing sleep over how to get another scope without giving one up. I want an MN190. Please stop this kind of talk immediately! 🤣

Other than price, I can see no good reason why it is not more popular. I think the 200P is going to have to go if I get one.

The MN190 is on my wish list, but something else will have to go to make room for it!

Track width on production PCBs is carefully controlled, well within 10%. It wouldn't need to be that fine, if you make it a long convoluted run. I've seen it done many times, same with inductors. At 5 V, you will only be getting 500 mW of heating, but like you say, the Pi is going to provide a lot more heat that will do the job.

I'm looking at all the resistors on that heater PCB and wondering why they didn't just use copper track instead of a bunch of expensive resistors. It's only 2.8 W and a PCB track of the correct width and length for the desired supply voltage could easily be accommodated.

The Olympus has a micro four thirds sensor, which is smaller than the crop sensor of the Nikon, but you will fit the full Moon on either sensor with the 1200 mm focal length of the 150P. You'll just have to chase the Moon more with the small sensor. It will also be better on the planets with the smaller pixels. The advatage of the Nikon is a much wider selection of lenses to choose from for other photography.

I am running a PC with 64 bit Windoze 7 and both Firefox and Chrome browsers work. Like @Zermelo I prefer Firefox for security reasons.

I can't understand why you didn't cut the flange off at the weld, then put the shorter pipe into the flange like the original. It would have been much easier and a lot stronger than attempting a butt joint.

Thanks.

Thank you! Yes, I was happy with what I got for the conditions and available time. It's a shame you got nothing useful.

Perfect collimation and perfect focus is definitely what it is about! The Moon was certainly wobbling a fair bit this morning as I tried to get focus and I ended up with just 32 frames bfore cloud ended play. My final result can be seen here: https://stargazerslounge.com/topic/415300-the-moon-this-morning-33-waning/ It's not the best I've had, but I'm happy with it, given the conditions and lack of time.

Moon imaging with the 200P and Nikon D800, this morning at 05:00. The sky was looking clear when I got up at 04:30, but by the time I was set up there was a halo around the Moon and I only got 32 images before the clouds came in and finished things.

@Roy Foreman My 200P and 300PDS are in near perfect collimation, now, so I just need to switch over from the Nikon D800 to my ASI 178MM, but am still in the process of getting that all set up. Hopefully, as others in here assure me, I will see a step change in results. Thank you for the encouragement.

I'm seeing a lot of lunar images that are similarly processed at the moment and I do prefer your usual approach, but this is still very detailed and a good image. Maybe you have been influenced by what you are seeing others do?

@GrumpiusMaximus my 200P goes out more often than any other scope I have, because, as you say, it is quick and easy. I can be out there and imaging inside of 10 minutes. 20 minutes and it is performing at it's very best. I have it configured to go on it's original Dobsonian base and it is fitted with rings and a Vixen dovetail to go on the Skytee 2 if I intend to spend more time with it. This gives me the best of both worlds.

@Roy Foreman very, very nice! Images like these give me encouragement. It is always nice to see what I might be able to achieve with the equipment I have, plus a lot of effort on my part. Well done dodging the clouds and getting such great final results. You must be pleased.

Wow! You have a lot of detail there. Even the brightly lit areas are looking spectacular.

@tooth_dr I would go with the helicoil. They are designed for exactly this type of problem and provide a stronger thread than the original aluminium. Plus, it will keep the equipment standard.

Dr Simon Batty, one of my physics lecturers at Sheffield University studied the shapes of asteroids for his PhD which I think he did at Bangor. I remember talking about it with him one time a few years ago and recall that it looked at the ratios of the side lengths which could well be linked to this. The number √2 was connected with the ratios.

The equation you give simplifies to D² - d² = DE² D = diameter of primary mirror d = diameter of obstruction DE = effective diameter Pi cancels throughout and for ratios it does not matter whether you use the radius or diameter. Yes, it is area that gives light gathering capability. Confusion arises here because we use linear measurement (i.e. diameter) to define resolving power, simply because we always talk about linear resolution not areal resolution. If we always talked in square radians for resolution (i.e. areal), then the light gathering and resolution would be equivalent in ratio and things would make more sense.