Adam J

You may have to buy one and let us all know. Looks very similar to the Altair astro cameras.

At two seconds you should see some stars but you may be too fat out of focus to see them. Try flashing a torch into the scope if the image doesn't go completely white you have a camera problem or you left the lens cap on 😉

QHY make the QHY-5-III 485c, sold by modern astronomy. Adam

Have piggy backed the entire Askar 180 setup on the top rail of my Esprit 100 for when I use it at home. Got the Az GTi for mobile use. Makes the Esprit look like a complete beast of a scope.

Really good image again and so soon after posting M101. As vlaiv says very small stars and great resolution. Shows how seeing limited everything is as I have seen countless images of this galaxy with hugh scopes fail to captuer as much detail. The short expsoures enabled by that sub 1e read noise do help that is for sure and I have noticed that I get much better detail in galaxy images when going with 30 seconds or lower exposures and stacking based on star shape / quality as I think you did here. No idea why more people are not galaxy imaging with this camera and whish that ZWO had not stopped making the cooled version of it. I know Padrepeace has an optical report for the scope, but that could send things off into a whole different discussion. Congratulations on another great image. Adam

Yeah those things are really good.

You have not defined your performance measures. However they will both achieve the same SNR in the same amount of time. But Jemima may not fit the object into the FOV of her sensor assuming the same sensor. One the other hand if the object does fit into the FOV of Jemima's scope Noahs may be under sampled by comparison depending on seeing. If Jemima is oversampled then she may bin in HW or SW to increase SNR or Perceived SNR. If they both have the same FOV and optimal sampling then Jemima will win. But one thing is for certain Olly and that is that Jemima will need significantly deeper pockets that NOAH and so theory aside most will be better off...(literally) going with Noah's solution and accepting the potential trade off in terms of resolved detail. In a nut shell that is why most people use a reducer. You say above that you don't increase her focal length. Fine but you did reduce Noah's So if they are both to be F5 Jemima must have a longer effective focal length than Noah. The other big issue with this is that while you can get scopes with almost any focal length you want you can't get cameras with any pixel size and sensor size you want. Hence you can't optimise your FOV and image scale to fully match your scope. If you could and kept image scale and FOV the same between Jemima's and Noah's imaging setups she would always win....but you can't and more often than not the camera is the same camera as it's one of only very few available, more so if mono. Adam

Spacing would not cause an issue in the centre of the feild like this. I believe that these scopes Guarantee 95% Strehl too....

I doubt that they refigure you might as well start from scratch as it would be just as expensive. They may well have been optimised for SA via spacing / re-centering and maybe had the elements optimised in respect to their relative rotations to minimise other optical aberrations such as astigmatism and higher order SA though. Adam

Yeah that not just a little bit out is it. I think you are correct and that is colimation.

Honestly I would not bother with a lp filter for LRGB. Assuming you have lrgb filters. It it's an emission nebula your imaging get a Ha for sure.

Yes was going to day the same thing you simply don't need a two inch. Filter for that camera and it comes with an adaptor for a 1.25 inch in the camera box.

I'll take that bet.

Yeah but those moon effected ones had to go.

A fantastic image Chris lots of dedication to the capture and perseverance with the processing. I love the detail that you have captured. This is not an easy target and you made it work with a uncooled camera. Congratulations.

Not something I will ever worry about in the UK, the last time it got to -10c down my way was the winter of 2010. But my comment was more about the Esprit 100 and 80 being optomised for imaging as opposed to visual, the 120 and 150 are a different story. On the subject of TAK scopes being worth the premium, I would go with that Olly said earlier. Adam

If you "looking" through an esprit I personally think you got the wrong scope.

No you made the correct choice the 533mc is the better camera by a wide margin and has no amp glow to need reducing in the first place. The only possible use case for the 183 over the 533 is in hyperstar or other very fast large aperture optics. But even then I might still chose the 533.

We know that they chap with the profile that says he lives in Texas and who took the image in early autumn was not imaging at any seriously negative temperatures, more likely positive and by a large margin. Edit: as noted sometime people even note the temperature down on astrobin. +10c in that case. We can assume Celsius given the bloke is french. My point is not that they where taken at low temps it's that these Takahashi scopes are pinched and form locations and dates we can rule out very low temperature in a number of cases. If it's happening to Takahashi and Borg and WO it's not just an esprit problem, it's a problem that's more common across the board than some people want to admit. OP could have asked about almost any scope and any brand and someone would have come back with a sob story about their pinched scope.

Nice image. Yes I think that the 80s have always been a little more hit and miss than the others, that I will agree.

I am sure they are, but clearly there are falling short more often that they would like to admit.

I worry more about quality control suffering as demand and pressure to deliver has increased.

And I just decided to go hunt for LZOS too incase people think I am attacking Takahashi. This is the second image of M45 I checked. https://www.astrobin.com/389995/?nc=all

They really are not hard to find, this TAK FS102 for example. https://www.astrobin.com/238557/B/?nc=all I don't think that one hit less than -25c in Texas... And this one... https://www.astrobin.com/full/260947/0/ Seriously all I am doing to find these is looking at images of M42 and M45 on astrobin. They are way easier to find than you would imagine. There are dozens more that are marginal too.

As with the TSA-120 above I just went looking for pinched optics on a WO 102GT triplet. This was literally the first image I checked. If it was not some poor chaps scope it would be funny. https://www.astrobin.com/403894/?nc=all