Adam J

A revision of my SHO data on this target from last year. Cant actually remember the specifics on the capture. But its an ASI1600mm pro on an Esprit 100 with AD 5nm filters. Here it is anyway. I should say I dont like the traditional pallet. Thanks for looking.....again. Adam

Might have just been a weakness in yours as opposed to a more general issue. Might be something that would 3d print. At least it not an expensive item.

I don't tend to tighten it down that hard. Not had an issue so far and never heard of this happening before on a forum and they must have sold thousands. Adam

I had exactly the same thought and asked ZWO that question about a year back. The response is that they have no such plans. They say the 533 can't achieve high frame rates unless you crop it allot for planetary and even then it's not great. For DSO they say they recommend cooling. But I agree with you for short exposures on fast optics it makes sense and for mobile imaging with lower weight and power requirements. Adam

I think vlaiv was being a little pedantic in that the signal is the same but the QE is different. In any case yes it will make a difference as said above you will achieve the same image quality in 2/3 the total exposure.

QHY just anounced this a IMX533 avaliable in mono and OSC, ZWO are making noises about a new camera being released, although not as specific in saying so i think it will be a mono 533. Adam

You get what you pay for in this case the ASI1600mm pro is still a good sensor at its price point in my opinion, but of course the 2600 is better and given the price delta you would really hope so. I think you will get better images from it in the end of the day Rob, you just need to decide if you want to pay for them. Also its not just the camera, in many cases unless you already have 36mm filters then you need to get the filters too and wow thats a big outlay. I run AD 1.25inch filters and I cant imaging paying for 36mm AD narroband filters. Worth remembering that with the lottery with some cheaper filters you could wipe out half your gain by getting a lower peak transmisson filter 90% vs 70% = 25% loss in effective QE and thats not unknown. Edit: this is exactly what I am talking about: Micro lens problem is a factor here thoug in my opinion and speed will translate into image quality one way or another. Expensive camera + cheap filter may perform less well than a cheaper camera and expensive filter and you may never know. Adam

Steve I did not say anything at all about ZWO I only said Altair = Rising Cam, fully aware ZWO make their own same for QHY.

Just trying to help and or save you money. Hence, I asked someone on astrobin who owns multiple branded cameras with the same chip for you. Look at the comments below the image. https://www.astrobin.com/3fwody/?q=Altair Hypercam 26m ""I also have the qhy268m and use all 3 for capture. They are all great cameras. In terms of build quality the QHY feels like its made better and it has the most efficient cooler of the 3. If I could only have 1 and I had to rank them it would be QHY, Altair, ZWO. The Altair cooler is also a little more efficient than the ZWO."" I highly doubt that you will find anyone on here with one, I dont recal ever seeing someone having posted an image from one, but I could be wrong. Adam

You say you dont want to hear it but ill say it anyway. The rising cam is the same thing exactly and much cheaper. Adam

I would say that the IMX485 is a more senstive sensor than the one in a 1200D by some margin. From what i have read the peak QE of that sensor is only 40% in the green and read noise is over 2e. With the 485 you are looking at more like 80-90% in the green and 1e readnoise. So long as the target fits on the 485 sensor there is no argument for the 1200D. Adam

My Esprit 100 would do what you are asking with a ES 34mm 68degree EP.

Would love o e of these scopes but it's lots of money for the aperture.

Depending on which filters you removed when you modified the 600D then you may actually already have an effective UV/IR cut in place. Here is another example of someone else coming to the same conclusion as me in respect to the blue bloat. L2 left and L3 right. I tried to link their original post on an German astronomy forum but I cant get it to work. You will probably notice the effect more on your mono camera which has a much greater sensitivity in the deep blue. Adam

depends on colour channel. Green is something like 1.333x native scale and blue and red 1.666 from memory, but its possible to work it out. If you are willing to sacrifice SNR for resolution and dither you can also regain almost all resolution by using bayer drizzel. But I do think that the GT71 was a great choice for starting out as it can be a keeper gives a reasonable with that sensor and if he went to a larger cooled sensor later it would still be a great match to many on the market. Adam

The point is more the untra low read noise of the 290 make ultra short exposure possible so if you dont have a good mount for AP you can still have a go and the short exposures mitigate seeing to a useful extent. Its possible that the 482 may work well as an OSC option. But in this area of imaging the 290 is a safe bet. Adam

300MM F5. With a ASI290mm, http://indexhamal.pl/astrofotografia/galaxies/images/NGC4490_ASI290MMC.png I have seen many examples with 1-5 second expsoures with a 290 at max gain. Works for small bright galaxies in mono. You do need to find the target though. Adam

Its possible that DSO lucky imaging of galaxies with a ASI290mm would be a good bet. 10k x 2second exposures.

maybe you can share from images or an unprocessed stack? Also which camera are you using with it? Adam

It will greatly reduce the blue bloat thats for sure but it may also kill your blue channel in the process making something like M45 or other reflection nebula more difficult than they need to be. Its also not cutting the near IR so well as the L3. My opinion is that you should wait for an L3. Adam

perhapse a link to the specific model you are suggesting?

The 705 is a higher f-ratio scope and a longer focal length F7 The ST80 is F5 and so as both are acromatic refractors you will notice allot more chromatic aberation on the ST80 than the 705. The 705 will also work better with cheaper eyepeices than the ST80. The ST80 will be better for viewing DSOs. But in either case you will only see the brighter ones and only from a reasonably dark site. All in all the ST80 would be the better choice for DSO but its a close call. So thats £189 vs £149 Here is what you get for £198 and its a significant step up from either of the two above for only another £9 pounds. https://www.rothervalleyoptics.co.uk/skywatcher-evostar-90-az3-telescope.html The issue you have is that at the very bottom of the market small increases in expendature generate big increases in performance. At the top end its the opposite, you pay a huge amount for a tiny improvement. Adam

This was the case with my 130PDS and i believe most SW Newtonians. Adam

Have you tried focusing on the moon? Easy to find, does it look sharp? Adam

Well you can buy an new scope as a beginner get a lemon and not realise it. Seen plenty of that even with some quite expensive optics on here.. But I would still recommend a new 705 for this reason, as support from an astronomy retailer is invaluable as a beginner and you do get some poor examples of scopes. In the end of the day my main advice is to get a scope with slow motion controls on the mount, lots of the scopes that have been listed here are essentially on camera tripods and so will be horrible to use irrespective of the optics. Adam