Cooled 350D a great success! :)

[Luis Campos]

Hi all,

First test with my peltier cooled Canon 350D, this mod prooved to be a great success! Even though it consists in only 4 frames of 2 min. each, the noise is minimal, I've streched the background a bit too much just to show how smooth it is, there is no post processing noise reduction applied whatsoever, just minimal processing like levels, curves and a bit of color boost, really happy with the results

This was made during a break in the clouds, so I didn't even had the time to collimate the 200mm f/4 newt properly...just crazy this weather!

Oh, i forgot to mention, I was expecting dew problem on the sensor filter but nothing happened, coooooool!

http://img521.imageshack.us/img521/9051/m3cooled4x2min800iso.jpg

Greets,

Luís Campos

[Chris]

Congrats:) thats an impressive result! I might have to cool my 350D it obviously makes quite a considerable difference to the noise!

Sorry to go off topic, I wonder if I could pick your brains about your f/4 imaging Newt? how do you find it to collumnate, and does it hold collumnation well? also how do you find the build quality etc, its just that I'm on the lookout for a Newt for the Obsy I'm building and I'm looking at the pro's and con's of f/4 vs f/5 ? There are also one or two others on here that I know would be interested in your thoughts also:)

[SamAndrew]

Nice result, no darks ?

Do you know what temp was the sensor was showing ?

[SamAndrew]

Sorry to go off topic, I wonder if I could pick your brains about your f/4 imaging Newt? how do you find it to collumnate, and does it hold collumnation well? also how do you find the build quality etc, its just that I'm on the lookout for a Newt for the Obsy I'm building and I'm looking at the pro's and con's of f/4 vs f/5 ? There are also one or two others on here that I know would be interested in your thoughts also:)

I have found the Skywatcher Quattro holds it's collimation well altho I haven't gotten it spot on yet, it takes quite a bit of fine tuning, and i think my laser isn't quite straight.

I haven't touched the primary on mine yet and I've had it 5 month now, you can see my results so far in my signature link, still needs some work to get the stars perfectly round, but it might be down to guiding, or my sensor orthogonality.

[Chris]

Thanks Sam, much appreciated I'll check out your pics:) and again sorry Luis for going off topic:o

Edit: love the pics from your Quattro Sam, lots and lots of data! for the number of subs. I can see a bit of an orthoganal issue with the bottom left of some pics but I get worse with the focuser sag on my ZS66:D

the Quattro looks very good!

[Luis Campos]

Congrats:) thats an impressive result! I might have to cool my 350D it obviously makes quite a considerable difference to the noise!

Sorry to go off topic, I wonder if I could pick your brains about your f/4 imaging Newt? how do you find it to collumnate, and does it hold collumnation well? also how do you find the build quality etc, its just that I'm on the lookout for a Newt for the Obsy I'm building and I'm looking at the pro's and con's of f/4 vs f/5 ? There are also one or two others on here that I know would be interested in your thoughts also:)

Cheers Starfox!

Thanks for your words

No worries, not off topic as it is parts of the imaging train

Mine is the Altair Astro version, same as Astro Tech, if you're used to newtonians i guess you'll find it quite easy to collimate but it need a few tweaks, the primary springs are waaaay to soft, just sweeping the sky makes collimation off, you'll need to assemble new heavy duty springs (available at your local hardware store, for sure) this is critical on a f/4 system. Another thing is the secondary mirror cell, it has a metal washer in wich the 3 collimation screws sit in, this washer need to be glued to the secondary cell, if not any car trip will make the secondary rotate on the center screw axis...this happened to me all the time, very frustrating to make fine adjustments on the field in darkness, so i glued this washer, end of story

It is imperative to use a coma corrector, I use a Baader MPCC and it's perfect (I also use it on my 300 mm f/5 newt. with excellent results) as coma will degrade a lot your images.

If you use a DSLR for imaging the fast f7ratio will allow you to use short exposures and low ISO values, this means you will drop noise in your images by a large percentage.

well, what can I say more??? This 200mm f/4 is here to stay...I love it!

Greets,

Luís

[Luis Campos]

Nice result, no darks ?

Do you know what temp was the sensor was showing ?

I Andrew,

Yes, I used full calibration here (darks, flats and offsets)

I have no ideia, i didn't install a temperature probe in the back of the CMOS. But i think it should drop maybe 12 to 15 degrees bellow ambient temp.

Maybe in a near future i'll put in a probe, better for darks

greets,

Luís

[Chris]

Thanks Luis, upgrading the springs and glueing a washer seems a small price to pay for such results, I know that an f/4 system will exagerate coma more than an f/5 so its good to here that coma is fully corrected, and I guess you only need to buy a coma corrector once so it looks like a good option to me.

Cheers

Chris