symmetal

Hi Marcel, Click on your user name at the top right of the screen where you login, then select 'Account Settings'. Select 'Signature' from the list on the left and then put the information you want to appear at the end of your posts in the Signature editable window. I believe your initial reply to me asked that question, but I misread as to what you were referring to. Alan

You'll need the 1.25" Powermate to fit in the eyepiece end of the blocking filter diagonal. I believe I needed a 1.25" extender (barlow with lens removed) too to achieve focus. If you only have the 2" Powermates they would have to fit before the diagonal which I wouldn't recommend as the extra heat generated before the blocking filter could damage them. Alan

You can if you insert the Powermate in the eyepiece end of the diagonal. An extender will probably be needed too to achieve focus. I did try it with my Lunt 60 but it gave bad Newton's Rings when used and gave no extra detail with my ASI178MM camera as the camera image scale at 0.99"/pixel is well matched to the scopes Dawes resolution limit of 1.93" without the Powermate. Alan

Glad it's working again. It's worth considering spraying all the USB contacts in ACF-50, to avoid damp causing future problems. This previous thread gives some information you may find useful. Alan

Have you tried reinstalling the Zwo drivers (native and Ascom). Alan

I just sprayed enough viakal in a cup to cover the filter and dropped the filter in it. Left it for around 20 mins turning it over half way through. Picked it out rinsed it in water and it's as good as new. Alan

Yes that's much better Alan. Hope you'll feel more comfortable with the camera from now on. Alan

CCD cameras aren't suitable for planetary imaging due to their slow readout speed. You need to take short exposure videos containing many hundreds or thousands of frames and stack the best frames. CMOS cameras are much more suitable and the ZWO ASI224MC or ASI290MC are highly recommended for planetary imaging as they are USB 3.0 and allow region of interest to be selected allowing frames rates of up to 200 frames per second or more. These are colour cameras which are easier to work with for planetary imaging. Alan

No problem Alan, at least you have the information should you need it in the future. The anti-dew tick box should remember its previous setting when powered off. It seems the USB2 problems you're having are adding to your frustration. By comparison, my ASI1600 which is the early version without the buffer for USB2 operation has never had any problems with dew or icing, still has the original tablets and I cool that to -30 over 10 mins each time. It doesn't have anti-dew and humidity is often over 90% here at night.

The black sticker on the side which Adam mentions does hide the screw to allow air access into the chamber. However this screw hole is to attach the little black tube which holds a couple of desiccant tablets to dry the air inside the chamber. This is meant to be used when the internal desiccant tablets have stopped working. This tube and 4 extra desiccant tablets was supplied with the ASI1600. But the ASI071 isn't supplied with the tube as it is now meant to be airtight inside so the tablets inside should in theory last forever. The later version of the 071, which we have, had the front redesigned so uses six screws to hold the front cover on instead of four screws on the earlier version to help achive the airtight seal. The internal four desiccant tablets aren't behind the screw hole on the side but behind the front panel. To access them you need to remove the tilt corrector by removing the three large screws on the front. This then reveals the front cover which has six screws around the outside which need to be removed. Remove this cover with the camera facing down to help avoid any dust getting in. Inside the front cover is a foam pad holding the four tablets. I bought a replacement set of tablets from FLO and changed them. But to recharge the old ones I would do as Adam says and use the oven. Before removing the front panel you can check the anti-dew heater is working by powering it from 12V and enabling the anti-dew in the Ascom driver. The plastic panel surrounding the front window should feel noticeably warmer in a few minutes. There is a flexible printed circuit board heater under the plastic panel. If you remove the front panel to change the tablets ensure it is replaced in the same orientation as it came off, as there are two spring loaded contacts on the main body which contact the anti-dew heater when it's assembled. As you have low humidity (much lower than me) I wouldn't have thought you wouldn't need the anti-dew so much. If the camera internal air has more moisture the sensor would form ice on the surface (as long as you cool below zero) before the front window dewed up I would have thought. As Adam says just try the camera outside on its own during the day and you should be able to see any ice/dew fogging forming on the sensor or window. Alan

Yes, that's much better focus Alan. I did have to replace the desiccant tablets in my new 071 after only a few nights testing when taking flats showed obvious icing on the sensor. It wasn't obvious on my previous night test images but maybe was on the verge of it. Maybe that batch of 071 camera had faulty or damp tablets. Alan

Ah! Sorry, misread the post. With fogging you usually get multiple diffraction spikes around bright stars which don't appear in your images, but give it a go with the cooling off to avoid that possibility. Alan

Alan, From the two Canon images you've just posted the focus is really very similar to the 071 images you've posted. I think when you get the USB3 module installed and use the bahtinov mask which is coming you should find focussing will be much easier and quicker. Alan

Hi Alan, Sorry to hear you're still unhappy with your 071. I'm not sure what the APT dew setting does but it's worth ticking the Anti dew box in the 071 Ascom Driver to ensure it's on. This does warm the warm the window in front the sensor and works whether cooling is on or off. I agree with Adam in that your image problems are mainly due to poor focus. Why the 071 is worse in this respect compared to your DSLR is odd as the sensors are similar regarding pixel size. Here's an uncalibrated centre crop of a stack of 4 min subs I took with the RedCat 51 for testing (simple stretch in PS) and the stars are pretty sharp. Flat frames are needed due to the blue drop off towards the edges and alternate pixels having a slight green hue if you magnify the image. I use a Lakeside Astro autofocuser with SGP and it autofocuses every 1 degree temp change. With your large initial temp changes it would be autococusing after every sub or so. Alan

Oops, sorry Merlin. I think it's just as you say, to show the frame at that green line position, and that's all. Left or right click seems to do the same. Alan

The green graph line is the subs ordered by quality from left to right, left being the best. The green line quickly falls from max quality to a lower quality value and then decreases more slowly across the graph before quickly dropping to very bad quality at the right hand side. If you choose to stack say 10% that means your using all the green line subs from the left hand side to the point 10% of the distance across to the right hand side. Depending on the seeing the graph quality drops more quickly so choose a point on the green graph where the quality is still fairly high and estimate what percentage of the whole graph that is. This is the percentage to choose to stack. I normally use between 10 and 20 percent. You have four boxes where you can enter the percentage to stack. You can fill them with say 2, 5, 10 and 20% and it will produce four stacks with the different percentages without having to repeat all the pre-processing, so is quicker. You can then examine the four percentage stacks to see which gives the optimum result in terms of sharpness and noise. The 2% stack should be sharpest with the most noise and the 20% stack should be the softest with the least noise. See how much sharper (and more noisy) your 2% stack is compared to the others. The others will be less noisy and the sharpness fall off may not be too much to worry about. Alan

Can you link to the Amazon description or say which model you bought on Amazon. Many come with WIn10 Home or Pro pre-installed but not activated. Activation is automatic when you boot it up the first time with an internet connection. This is normally stated in the Amazon product description. You can possibly buy a version with no OS installed which would be cheaper. Alan

Have you got the mount tracking 'East heavy' to keep the gears meshed and to avoid the RA possibly 'floating' across the backlash area and causing an effect similar to what you have. Alan

Good idea. Worth a try. Alan

Thanks Julian. I'll order a set of tablets from FLO and see if that works. Alan

Looking through the window it looks like there are internal desiccant tablets as shown. There are two others on the other side. Alan

Ah! So it might have both. I was reluctant to open the camera up to avoid getting dust on the sensor. It seems odd leaving the internal ones in place 'full of water' and using the external ones to try and dry them out a bit. Maybe that's why the external tube has been dropped. I would have thought information on replacing the internal ones would have been mentioned somewhere again. I think the tablets FLO sells are the internal ones and from your post they are a different size to the tube ones. I'll have to get a pack from FLO to try and fix it. As it's a new camera it implies the chamber isn't very airtight anyway so won't fix it for long. No problem Alan. Actually I was a bit misleading in my post in that the anti dew heater heats the window in front the sensor to stop dew forming on the window when it's humid. The sensor chamber should be airtight so the outside humidity shouldn't make a difference to the sensor. Mine apparently isn't very airtight. If the sensor is icing up the anti dew heater on the window won't make any difference to it. You could just check to see if your sensor doesn't ice up below zero C if you are able to but don't worry if you can't reach that low a temperature. The anti dew heater is turned on here in the Ascom driver. Also if you need to set the Offset or USB Limit you have to tick the 'Advance' box too. Alan

Thanks Alan, Yes, the enclosed instruction booklet refers to the ASI1600 which is poor. You can get the proper full manual from Zwo's website. Thanks for the offer to help. If you have some damp weather it would help if you cooled it to say -10C with and without the sensor heater enabled in the Ascom driver to see if it does freeze up and whether the heater makes a difference . You just need to visually look at the sensor to see the ice forming so there's no need to fit the scope. With mine there was no change in the ice formation with the heater on which is odd. The early 1600s had the 4 tablets inside but later ones incorporated the removeable desiccant tube which is screwed into an access port in the side of the case. The ASI071 has the access port. I've used the threaded metal tube and tablets from my 1600 and fitted it to my 071 to see if it helps, (after 24 hours). If I never had the 1600 I couldn't have done anything as the 071 doesn't come with the tube and tablets. Most odd. FLO sell replacement Zwo tablets but not the tube which is needed. On the CN forum discussions do mention using the tube so must be referring to the early 071 which did include one. Replies mentioned that on the Zwo forum Zwo recommend leaving the desiccant tube on permenantly once you have to use it. Alan

Went to take some flats for my new ASI071 Pro but the sensor iced up at around -10C. It was humid and I hadn't turned on the Anti-Dew heater so warmed it up, enabled anti-dew in Ascom driver, but it made no difference. It just iced up again. I was allowing 10 mins for the cooling. I'd only used the camera for tests on a couple of nights previously and it didn't appear to ice up though it was a dry night. The new 071 Pro doesn't include a desiccant tube and tablets and the manual makes no mention of the desiccant tube either. The older ASI071 Cool does include the desiccant tube and tablets and the manual does include instructions. Does anyone know if the 071 Pro version is meant to use the tube method (if so why isn't it included) or not?. My 2 year old ASI1600 has never suffered from icing up even on damp nights and cooled to -30C. I do have the tube from the 1600 I could use and the 071 does appear to have the access port on the side. Alan

The only problem may be the camera reaching -20C during the day when the ambient temperature is higher. Having a desk fan or similar blowing across the camera can get you an extra 5 degrees cooling or so. You may want to take the camera off the scope and fit the metal dust protection cap that came with it to ensure no light leakage. Assuming it is a metal cap. Black plastic caps do leak light. Alan