Adam J

Yes bringing out a very old camera in Blue is the most I have seen from them recently.

They posted on their web page that they halted production to focus on medical imaging cameras due to Covid-19.

OSC = One Shot Colour, hence a colour camera with filters incorporated into the sensor photosites that make it possible to derive a full RGB image from a single exposure (hence one shot). Mono sensors lack these filters and so are more sensitive as each pixel receives much more light that would have been absorbed and lost in the case of the OSC sensor.

Wait for the mono, no matter how good an OSC is a mono verson of the same sensor will be twice as good again. Hence why mono is going to be around for the forseable furure, there will always be applications that demand the highest possible sensitivity in low light and even when they move to stacked OSC imaging sensors there will still be a hit to read noise, dark current and QE in comparison to mono so people like sony will not stop making them. Adam

I posted that three months back and in that time alone we have had new cameras anounced or at least confirmed as in development based on three new mono sensor types, it is said they will be released to the market by the end of the year. I see more OSC cameras on the market these days sure, it was bound to happend with the change to CMOS in astro imaging, but what I am not seeing is a reduction in the avaliability and divercity of mono cameras, if anything new mono cameras are also being released at a higher rate than historically under CCD technology. If you read the entire thread I have put forward strong evidence in support of my argument that mono is not dieing a death any time soon. When I said with all due respect to Ian, I mean with all due respect to Ian, there is no subtext or sarcasum intended in that statment. I know his credentials and have spoken with him on a couple of occations he is a great guy who really knows his stuff. But as I said earlier so long as you are willing to make a reasoned argument, as I have, then its ok to disagree with someone. The title of the thread is "is everything heading OSC" the answer is almost certainly no. If the thread had been titled something like "are modern OSC sensors becoming more viable for astro imaging and hence reducing mono market share" then I might agree with that statement. Adam

What are you using for your mosaics Rob as I know for sure that APP would cope with the kind of distortion you are describing easily. Adam

One more for dithering and not just a couple of pixels either nice big dithers of 50 or more pixels to combat banding.

Yeah that really is poor customer service.

Hey happy for you! Be sure to post your first light here for us all to see!

I will concede to the consensus of opinion John. As you say OP is well within his rights to return the scope if he is unsatisfied with its condition, with it in front of him he is best placed to judge. My unfortunate situation was much more complex and I decided that 5 months on from spending 1.8k on a scope (2 months wait for scope #1, one month ownership and then two months wait for its replacement, none of which was the fault of my supplier as Esprits where in very poor supply at the time) I was not going to send it back for yet another without at least trying to blow the dust off the inside of the second scope myself. The end outcome was that I was very happy I did not have to send another scope back, so I did not put up with it as much as took matters into my own hands at that point. Hence, having been through that once I am probably seeing things through a different prism to everyone else and my reaction is to suggest what worked out for me. That being said I concede that my situation was more extreme and I dont think the OP is in that mind-set yet by a long way, so in retrospect, I bow to the opinions of others and I agree he should send it back. As a final thought, when retailers are basically saying that this is just the way it is, its probably a good indication that SW have a wide spread problem that they need to get a grip of. Adam

No never remove the lens cell as you say, it would loose colimation and you would be in for a world of hurt. You dont need to do that with the Esprit to give the rear lens surface a blow though. The esprit tube is very very short and so all you have to do is remove the focuser from the back which comes off very easy due to the excerlent way SW chose to implement the rotation mechanisum on the esprit series also goes back just as easy. All you do is rotate the silver collar by hand no tools required. He can always ask their permission, if they want a happy customer and to avoid lots of pain and having a open Esprit to get shot of for no reason they will say yes. Or he could return it and they could do it on his behalf, but no one should have to remove or indeed touch the lens cell. But both the Esprit 100s I have had (the first one had a actual optical issue and was exchanged), had some dust on the inside of the cell, hence I dont like his chances of getting one that is 100% clean if it is exchanged. My theory is that they are assembling clean lenses with tubes that are not handelled / stored with as much care and so during shipping material falls off the inside of the tube onto the lens. Admittedly if the material is between lens elements I would be less happy. But I am thinking that most of it will be on the rear element outer surface. Adam

If its on the lens rear surface then it can be fixed or you can blow it off youself. If it really is between the elements then its not something that can be done without disasemblin the lens cell and that required a optical lest bench. It would take many months for you to get it back in that case. Adam

I think it was very clear that you have a different opinion to mine from your original post, which clearly stated your opinion, as such I find it odd that you feel the need to explicitly highlight that your opinion is different to mine in an additional post. I dont think that the OP is in any danger of accidently thinking that we agreed. Without testing it for all we know its the finest figured Esprit 100 lens ever to come off the production line. It could have 0.99 Strel and he may exchange it for one that is bearly diffraction limited but nice and dust free. I know which one I would take, which one would you take? Now he may also test it and find there is another issue in which case he has a solid reason to send it back. Adam

Is it between the elements on on the rear surface? It often looks like its between when its on the rear surface. The tube is to short that you can just remove the focuser (turn the wheel behind the focuser counter clockwise until it comes off), once you have it off you can just use a rocket blower to blow the dust off the rear, just mind the baffels. They are not assembled in clean rooms and to be frank you will get dust on it within the fist few hours of use anyhow, I know it it not the best from an unboxing of a new scope experiance but , mine was the same, I did not let it bother me and you should not let it bother you. My advice is to perform a star test on the optics, before you send anything back. there is always the possibility that you will send a fine optic back because of some dust (not that i would expect an exchange on the basis of dust) and for the sake of a few particles of dust you could get a inferior optic in exchange. Adam

If you did make an adjustment it would literally be a fraction of a mm. Personally I would find that result acceptable though and just crack on with imaging. Adam

I would think it will depend on your focal length. Adam

You are looking for something like an ICRON Ranger, but such devices are not cheap. Sold one recently. Adam

Yes exactly, my thinking is that for my portable setup that I will use only a few times per year I do not want a £700 socpe sitting about gathering dust. Adam

Depending on a great many other factors you may want to consider an off axis guider for work at long focal lengths. Adam

I have one, its a really nice bit of kit. I am going to review but my camera is currently mounted on the Esprit finishing a project so I only have a quick test image at the moment. But from the test everything is looking good and it has a nice feel to it too. I would hesitate to recommend it until I have a full image for obvious reasons but from my perspective at £350 its was worth a punt and it looks like it will pay off. Adam

I would say there is no way that a Samyang 135 would give good corners on a 6200 sensor the pixels are just too small and unforgiving. But I am not sure why we are talking about a lens in a thread about a large refractor anyway. There is a very new ASI2400mc pro coming out not to be confused with the smaller ASI2600mc Pro, at that focal length I would go with the 2400 as its even more sensitive. *****************Forget all that just seen this is about the mono version, my mistake. Adam

Let me guess astrobackyeard? At anyrate its too close i would add 2mm or so. Adam

I will be interested how you do when you have the B-mask on to focus as to my eye the left side is less sharp than the right but if focus is not perfect it will show up even the smallest tilt as I am sure you know. so ill stop teaching you to suck eggs. Adam

I doubt that many own both but you are in luck as I do, the Orion 50mm guides my Esprit 100 in an observatory, I would say its optics are better and it more ridgid to prevent flexture so long as you have a good quality finder shoe. Sure the SV has a better focuser, but to be honest I focused the Orion 50mm once and have never touched that focus in about 2 years.... Adam

Unity gain should work great. Optimal exposure depends on sky brightness and read noise but 3 mins seems longer than necessary.