MarsG76

2 minutes ago, Thalestris24 said:

Hi

If you spray a coating on remember to tape over all the cable connectors first                                                                                

I have a cooled mono 550d (sadly not working for a few years) that I used to set the temperature to +5 deg which seemed good enough. I don't know where the set point temperature sensor is located - I imagine it's  fitted close to the sensor.

Louise

Hi,

Covering the connectors, thank for the tip, I was going to do that of course.....

I inserted another temperature probe inside the 40D, sitting just above the sensor, hopefully this will give me a good ball park figure of the temperature... this probe will be connected to the temperature controller which will turn on/off the peltier to keep the sensor between the upper/lower set temperature.

If the above measures fail to keep the front of the sensor dry, I will wrap and glue some nichrome around the front of the sensor frame (as suggested by @Stub Mandrel, match the resistance of my dew heater strips and connect it to my Astrozap dew heater controller. I figure that the IR cut filter is removed so there is a few millimeters gap to play with for the wire and glue around the front of the sensor.

5 hours ago, Stub Mandrel said:

Nicely done.

Not sure if the 450D has a different sensor arrangement, but I had to push my cold finger between the sensor and a PCB above it.

Don't be depresses if the EXIF shows only a small temperature reduction - the image sensor is well away from the temperature sensor.

I covered all my electronics in hot melt to prevent moisture getting in and add a bit of insulation. Any insulation you can add to the uncooled parts of the cold finger will help a lot. I used a 3D printed cover for the back of the coldfinger, filled with foam.

I had to fit a nichrome wire around my sensor cover glass to stop it getting condensation/icing up.

 

The other anti sensor dew counter measure is wrapping a dew heater strip around the T-Adapter around the front of the DSLR... that might keep it dry also....

3 hours ago, Stub Mandrel said:

Nicely done.

Not sure if the 450D has a different sensor arrangement, but I had to push my cold finger between the sensor and a PCB above it.

Don't be depresses if the EXIF shows only a small temperature reduction - the image sensor is well away from the temperature sensor.

I covered all my electronics in hot melt to prevent moisture getting in and add a bit of insulation. Any insulation you can add to the uncooled parts of the cold finger will help a lot. I used a 3D printed cover for the back of the coldfinger, filled with foam.

I had to fit a nichrome wire around my sensor cover glass to stop it getting condensation/icing up.

 

Nice project, well done of your success... as far as the PCB location on the 40D is concerned, it's in the same position as on your 450D, and the cold finger needed to go between the sensor and the main PCB.

@Thalestris24 got me thinking more about the dew/condensation on the electronics so I ordered a can of "Conform Coating" to cover the PCB to help with the moisture. As far as covering the PCB in hot melt or glue for insulation, that is not an option since the thickness of the glue would far exceed the amount of space between the components, it's already tight, let alone with a few millimeters of the melt on the board, so I thought that the conform coating is a better option.

My other plan is to keep the cooling just above the dew point as I do have a unit in the observatory that shows the temperature, humidity and the dew point temperature.

My question to you is regarding the nichrone wire around the sensor. Was the nichrome wire around the sensor necessary due to the sensor actually frosting over in practice or was this a preventative measure? Reason I ask is because I added two peltier coolers to the sides of my DMK41au02 CCD, which were running uncontrolled and even though there was a heap of condensation dripping off from the CCD, the actual sensor remained dew and frost free... I put it down to the sensor generating some heat, heat rises as the camera is orientated upwards, this being enough to keep the front of the sensor dry.... flawed?

Generally the coldfinger works like the peltiers on the case of the DMK41, ie secondary heat extraction via a medium, and on the DSLR only 1 peliter being used.

If the need for the nichrome was needed due to actual frosting of the sensor, did you power it via a dew heater controller or just run it of a 12V uncontrolled source? What is the resistance of the nichrome around the front of your sensor?

Looks like there's a bit more to think about with this project than initially anticipated....

2 hours ago, Thalestris24 said:

Hi

You probably need to spray/coat the pcbs to prevent problems with condensation

Louise

I was thinking about that, but I'm under the impression that condensation (ie distilled water) won't conduct. I'm more concerned about the rust on certain parts.

Hi All,

I finally had a chance to start my active cooling mod of my astro modded Canon 40D. Initially I started with designing the shape of the cold finger and creating a to scale template on paper...

I made two designs, one with bends around the sensor, and one which is mostly flat with minimal bends. I went with the latter since I figured that I will not be able to bend the copper plate with such precision using my available tools... ie two pieces of wood.

I cut out the cold finger on the copper plate and after bending the cold finger into shape, I realized that there was a bit of a gap between the copper and the sensor...

...so I cut out a piece of copper 1mm smaller than the sensor on each side and inserted this in between the cold finger and the sensor.

Hopefully (with the use of heat transfer paste) creating contact and being more efficient in extracting the sensor generated heat.

I used the existing screws to hold the cold finger in place, three screws should be secure enough to hold it in place.

Now that the cold finger is in place, it is time to put the camera together. 
 
There is not much room inside the camera and so the mod is very tight.
The main PCB is a tiny bit offset and inserting the compact flash card is tighter than normal, as is inserting the mini-USB cable. At this time I was expecting the camera not to power on but...

... it's alive... ALIVE!!! I've taken a shot of the light without a lens and the white frame tells me that the sensor still works.

There is enough room to use the side connectors as needed. The most important connectors are the USB connector which will be used almost exclusively and the remote trigger connector which I'll use when I'm not using the laptop.

Part 2 of the cooled DSLR mod is a success, all that's left now is to bend the outside plate 90 degrees to the front, install the peltier cooler, heat sync and the temperature controller....

Clear skies,

Mariusz

One hell of an image and a monsterous task... WELL DONE.... This is the best M31 image I have ever seen.... that includes the pros...

Interesting project, but wouldn't communication between the ISS and base be digital and encrypted?

Just Android, not iOS?

5 hours ago, johninderby said:

I’m wondering if an individuals light sensitivity or eyesight in general makes a difference in what filters work or don’t work for them. I found the Contrast Booster to be of little help but found the Neodynium makes a real difference in detail on Jupiter for instance. 

Most likely it does.... out eyes are the last refraction before the optical nerve, so it's certain...

beauty is in the eye of the beholder scenario...

10 hours ago, johninderby said:

The Neodynium  filter is also my favourite for lunar. Really helps bring out the details and gives the moon a nice neutral colour. No off tinges.  ??

Personally I use the variable polarizer on the Nagler 31mm and Ethos 17mm with the use of the 2X powermate... that combo has given me the views you describe... BUT I'll have to try the Neodymium on lunar now...

10 hours ago, johninderby said:

BTW everyone on this forum is always ready to help you empty your bank account. ?

It's a friendly competition of "who dies with the most toys wins"... and we're helping each other to win ? 

8 minutes ago, paulastro said:

Is this the filter we are talking about?

https://www.firstlightoptics.com/light-pollution-reduction/baader-neodymium-filter.html

Yeah, I'm very sure its teh same one with the moon and skyglow part dropped from the name.

15 minutes ago, paulastro said:

Many thanks for that, even more food for thought.  What is the actual name of the filter we are talking about,  is it the Baader Moon and Skyglow or Baader Neodymium? 

The one I have is called Baader Moon & Skyglow filter, but I its the same as the Nedymium filter from what I understand...

I have this one:

https://www.ozscopes.com.au/baader-planetarium-moon-and-skyglow-filter.html

57 minutes ago, paulastro said:

The bulk of this report in was posted by me in response to a post on Mars and I have re-posted it here in an edited form as I thought it may have some appeal to planetary observers who have not seen the original.  There is a lot of other information on line and I'm apparently not the only one who is VERY impressed with how good this filter is for planets.  It's by far the best filter I've ever used for planetary use, and I'd urge anyone who can get hold of one to try it out.  As you will read - I've never previously been impressed by the use of colour filters for the planets.  For me the Baader Contrast Booster is now an essential item of my planetary observing kit.

 

I've had a set of colour filters for donkeys year and occasionally get them out, often at a Mars opposition, but the result is always the same to me.  They never seem to show me anything I can't see without them.  They make some features on Mars more obvious, but at a cost of and unacceptable colour cast (to my eyes) and a darkening of the image according to which filter it is of course.  I hadn't tried them this year as the result is always the same for me. 

However, I thought I'd read up on which if any of the colour filters themselves might show some details of the dust clouds, at least it would be something to look at.  I found nothing convincing enough to encourage me to dust off my colour filters again.  I then looked in a draw of oddments to see what filters, other than colour filters, I had I might try.  I found a Baader Contrast Booster which I'd forgotten about, never used it - it came with a scope I bought eons ago.  I googled it and found it had rather a good reputation for being useful for planetary images and in particular some people seemed to think it was the bees-knees filter for Mars.

Anyway I tried it a few mornings ago, and was quite taken with how it improved the sky contrast, quite considerably without dimming the image to any great extent at all.  Also, I did glimpse indications of some albedo marking on Mars more frequent and certain than I have ever done without it.  Also tried it on Saturn, a good image with the contrast particularly noticeable on the difference to the sky detail and the background stars/satellites I could see.  The great thing for me is that it does not give a horrible colour wash to the images as colour filters do.  I think it has a slight biased towards yellow, but I only really noticed it on the Moon, and it was nowhere as bad as using a yellow filter.  The following evening the GRS transited the CM on Jupiter and wow, what a difference.  The GRS itself was immediately easily discernible and clearly pink even in poor seeing periods and the belts and other detail were clearly well enhanced.  Easily the best view of Jupiter I've has this apparition.   If I'd know it was as good as this I'd have used it years ago. 

Anyway, I really just wanted to say to anyone that happens to have a Baader Contrast booster in their arsenal, to try it on Mars and other planets if you haven't already.  To me at least, it was quite a revelation.  If I'd tried one belonging to anyone else I'd have been straight on to FLO to buy one the next day.  If you know someone who has one locally, pop round and try it and see what you think for yourself.  I suspect when the dust clouds clear it will really show its usefulness even more.  Worh having for Jupiter alone in my view.

If anyone is wondering, I was using the filter with my ES David Levy Comet Hunter, a 152mm f4.8 Mak-Newt, binoviewer and two Baader MK111 zooms.  This scope performs very well on the planets without the filter when the seeing plays ball.

https://www.firstlightoptics.com/achromat-semi-apo-filters/baader-contrast-booster-filter.html

21 minutes ago, johninderby said:

The Baader Contrast Booster filter is OK but find the Baader Moon & Skyglow is an even better planetary filter particularily on Jupiter. Have you tried the Moon & Skyglow for planetary?

Had both filters but ended up selling the Contrast Booster.

I agree that both the Contrast booster and the neodymium (AKA Moon and Skyglow) filters are amazing... the thing that really surprised me is how amazing the views I have had when they were stacked.. Jupiter and Saturn are so full of detail on a good seeing night, it has to be seen to be believed.... 

Now there is a sort of a catch.. the order in which the filters are stacked DOES MAKE A HUGE difference... I found that when the Contrast booster is directly on the eyepiece and the neodymium filter is added to the contrast booster is when it works best, the other way around is almost no better than not using the filters at all only dimmer.... 

21 minutes ago, tooth_dr said:

 

Thanks MG ??

You're welcome, keep'em comin'...

Very nice camera and image...  

On 07/05/2018 at 17:39, happy-kat said:

Same, image capture, processing, submission all within the dates. The submission folder closes at the end of the challenge period.

I'm in... I guess I'll have to process as soon as I grab any decent data... I'm hoping for a good Mars toward the end of July, although that dust storm is a bit worrying.... on another thought, it might make for an interesting image.

I'd assume that there is none.. I'm using a Hirsch f6.3 FR and it works every bit as good as the Celestron so I'd say they're all from the same manufacturer.

I agree with Spillage above... round stars is a good indicator of good guiding. Generally if your guiding is less than the angular distance per pixel in arc seconds than you will have subs as good as you can expect, even with lower guiding error.

The guiding accuracy is dependent on your atmosphere stillness, for example I don't know how the HEQ5 compares to the CGEM but with my CGEM I get 0.4" at best, but most of the time I can expect 0.6-0.8".

For you telescope, 114mm , you don't really want to magnify much more than 200X.. and this is during better than average seeing.

At 1000mm focal length your scope will magnify 166X, so even using a 2X barlow with it will be over kill for your aperture. As a rule of thumb, about magnification of 50X per inch of aperture is best for planets when seeing allows it... so that translated to 224X for a 114mm mirror.

The best eyepieces for your scope, I recommend is a 11mm Televue Nagler Type 6 with a 2.5X powermate. This combo will give you nice and clear views, mobility to magnify at around you scopes theoretical max power and half power. Add to this combo a Baader Neodymium and Contrast booster filters and you will have nights where you'll end up with a smile ear to ear which will still be plastered across your face when you pack up and lay down to sleep.

Don't forget to collimate.

Hello and welcome to SGL.

21 hours ago, Pete Presland said:

Ends on 31st July, so it will cover opposition of Mars.

What about processing time?

Ending on the 31st May is a bit early since Mars will be at the best position to image (and view) last week in July AND 1st week in August.

No, remember that a telescope will last you many years, if not rest of your life.. so I don't think its a waste of money since you will get use out of it, with amazing views over time.... a waste of money would be determining that it was a "waste of money" and selling it for half of what you paid.

I'm sure that you have other items you bought which you perhaps haven't used for longer than 6 months...

You wont think like it a waste once you see Planets of nebulae of a particularly crisp night that will make you go "Oh WOW"... and even if you did have your scope out every night, the chance of having conditions that are amazing every night is low... this way it'll keep you hungry for more.

I agree.. the baader glass is not needed...

When I modded my 40D, i removed both of teh pieces of glass at the from, one, the thicker one, looks blue, so it was removed but I replaced the other piece of glass.. it looks clear and protects the sensor..

My Halpha and SII sensitivity is pretty good for a DSLR.