Adam J

The ASI183mm pro never have an issue, its a problem for their larger sensors ASI071mc pro and ASI091mc pro due to the sensor being so close to the cover glass and the increased cooling power needed for a larger sensor. I think that in response they have increased the back focus on the new ASI2600mc pro and ASi6200mm pro to more than their normal 6.5mm to combat this issue. So they may have fixed it in doing that. Adam

In all honestly I think that I would go with QHY in this instance just because of the issues ZWO have had with the cooling on their larger sensors. But I know ZWO have re-designed their camera mechanics from the 071 so this time they may have gotten it right. On the other hand QHY sometimes have issues with their drivers on first release that are then fixed at a later stage. But while you can fix drivers you cant easily fix a sensor chamber that ices up. Looking historically very few issues reported with the QHY168c and lots with the ASI071mc and even the later pro models seem to require desiccant replacement on a more frequent basis than most cameras, I have read a few people saying that they have had to renew the desiccant right out of the box. Not that I own either, I just read lots of forums and have a good memory for facts and figures. £1800 for a 268c seems like a good deal to me, QHY often do this as they like to get products out into the market early to drive word of mouth etc, it will go up in price after that. Not sure what ZWO are asking for the 2600 but historically it will be more than the QHY version. Adam

Better but more than twice the cost. This is more in competition with the ASI294mc pro and the ASI183mc pro sitting between them in terms of price and closer to the 294 then the 183 in terms of performance, its a budget cooled dedicated OSC that I would expect people to choose as a first camera. The ASI2600 and QHY268c are more mid range, they represent a step up from the ASI071mc-pro as they have larger APS-C sensors and are in a higher price category. The per sensor area performance will be similar between the 533 and 2600, so what your really paying extra for is additional sensor area, just make sure your scope will cover a APS-C with a flat field, a surprising number will not. After that its a case of what can your budget stretch to. Adam

You need a fan under it really pushing air up into it . I have seen people place an inverted dust bin over a pier and add forced air ventilation. That works much better than a cover. https://www.skyatnightmagazine.com/advice/how-to-build-a-back-garden-telescope-pier/ Would still add a fan even with a bin though. Are you keeping everything out or just the mount?

Looks like the secondary mirror is rotated is this image. From the look and f the shadow and the location of the draw tube relative to the primary mirror reflection.

It's not something I would do with my equipment. The problemn is lack of ventilation. You need to force air through it.

Unfortunately it is likely to be different in due to the 14bit vs 16bit A/D. Although this does give a slight indication.

Ah well that will make it about £850 in UK pounds including tax. Still that is dam good, very close to the ASI183mc pro that FLO currently sell for £799....unless you really want those tiny pixels for some specific use case £50 more is well worth it.

No I don't, but they do quote a range from 1e - 3.5e gain dependent. Normally for ZWO the higher figure quoted is zero gain and the lower figure 30dB gain. So a more useful 20dB will be some place in the middle but closer to 1e than 3.5e I should think, my guess around 1.4e. Adam

MY GOD ONLY 772 euros! That really will kill a chunk of the 183's market segment.

Yeah, what i put down is correct, thats just high point being rubbish and confusing the specs of the two models, as for the read noise. 3.5 / 3.8 are at zero gain, its much lower than that at 20dB gain. They are the same pixels as the ASI2600mc pro but the noise is slightly higher at low gain due to the quantization noise from the 14bit A/D vs the 16bit A/D. Adam

Very nice, you could get a great wall print out of that if you can find a company that does custom sizes. Do you have dynamic distortion correction or equivalent on pixinsight as per APP? I see some channel misalignment to the bottom of the image.

To be fair though that is a pretty sensible range of times.

Very interesting OSC sensor at a very interesting price. https://www.highpointscientific.com/telescope-accessories/astro-photography/ccd-cameras/zwo-cmos-cameras/zwo-asi533mc-pro-usb-3-cooled-color-camera-asi533mc-p In a great many applications this is likely preferable to the ASI183mc-pro as at focal lengths longer than 400mm (or less even) the pixels on the 183 start looking a little small. This will also be a much more sensitive camera with the read noise / unit area being much lower than the 183 while having just as much QE. The ASI533mc will be well matched for focal lengths from 250mm to 750mm. Of note is the 14Bit A/D as opposed to the 12Bit on the ASi183mc-pro. Also just look at the full well!! and read noise values, the dynamic range on this sensor will be off the chart. 3000 x 3000 pixels makes for interesting framing as its quite a rare thing to get a square sensor. On the positive side it will put little demand on the optics. See comparison with 183 below at 400mm focal length. In essence what I am saying is that at the proposed price I can think of very few reasons to chose a 183 (unless you want mono) once this is released and most of those are very niche. Sensor: IMX533 Square Back-Illuminated CMOS Resolution: 3008 x 3008 Pixel Size: 3.76 μm Sensor Size: 11.31 mm x 11.31 mm Max FPS at Full Resolution: 20 FPS Read Noise: 1.0e-3.8e QE Peak: >80% Full Well: 50,000 e- Exposure Range: 32 μs - 2000 s ADC: 14 bit I hope / expect this to set you back under £1000 in the UK, preferably closer to £900 but no one has it listed here yet. More than that and it competes with the ASI294mc pro on price leaving the only real advantage being the smaller pixels. Would love to try one of these with something like a WO Redcat as part of a portable setup. Adam

Take a look at this, very similar. https://www.facebook.com/photo.php?fbid=10157786799877813&set=gm.10158939903337388&type=3&theater&ifg=1

And that is the thing, you can issue updated drivers but you cant fix a camera that ices up constantly due to poor design. In my opinion the QHY168c is far better than the ASI071mc pro.

Asi2600mc pro is the same sensor. QHY do have good drivers in general but not always from day one.

Look at every setting it's Always possible to accidently tick something.

My next guess was going to be that you are applying debrayering to a mono image. Is it rotated such that the grid is to the sensor if rotation had not taken place.

What program are you using? APP? Normally I would say to take a look at the master flat.

So the last image is a single sub and not calibrated? What are you using to stack and align?

What you need is a buck converter with boost at the far end of your cables close to the mount that way the voltage drop won't matter. But to be honest I think you are far better off still placing the power supply in a waterproof box and feeding input and output cables through a rubber grommet.

That is not far away from what most dedicated cameras with larger sensors draw. My ASI1600mm pro is about 12volts at 2 amps for example, its a smaller sensor than the APS-C in that camera. You are going to be looking at a deep cycle caravan leisure battery if you want to go over 3-4 hours. Or just multiple power tanks. Something like this perhaps. https://www.amazon.co.uk/SuperBatt-LM110-Leisure-Battery-Motorhome/dp/B00Q8N66B0/ref=asc_df_B00Q8N66B0/?tag=googshopuk-21&linkCode=df0&hvadid=310315668927&hvpos=1o5&hvnetw=g&hvrand=16988168541733981736&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9046228&hvtargid=pla-888864803952&psc=1 Adam

You set the camera into bulb mode and use an external intervalometer that you can plug in near to where the screen attaches. https://www.amazon.co.uk/Qumox-intervalometer-remote-shutter-Camera/dp/B00C1C0WQC/ref=asc_df_B00C1C0WQC/?tag=googshopuk-21&linkCode=df0&hvadid=309924713643&hvpos=1o1&hvnetw=g&hvrand=2919213887095309724&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9046228&hvtargid=pla-561829304366&psc=1 This is possible when controlling the camera via a laptop and a program like Backyeard EOS, I am not sure if its a option on the menu system incorporated into the camera though. https://www.dummies.com/photography/cameras/canon-camera/how-to-enable-mirror-lockup-on-the-rebel-t5i/ I am not aware of a feature like this being present on the 700D. In general most would use a laptop with this camera when on a telescope, if using a camera lens at shorter focal lengths then I doubt that you would notice any effect from vibration anyhow. It wont have as many integrated features as a more modern model but the effect of the cooling should be very signifficant and more than make up for what it lacks in bells and whistles. Adam

You might have DSS in superpixel mode.