DSLR HA Rosette Nebula

[Maximidius]

This is 4hrs of 900 sec subs at iso 800 with my DSLR and a Baader 7nm HA filter. Imaged over two nights because the first night was so windy I lost 50% of the subs second night started good but got foggy. No darks, flats or bias in a bortle 6/7 sight under an 86% moon with poor seeing and transparency. It aint gonna win any awards but im happy with it. Hope it's likable

 

[wxsatuser]

Very nice Ha Rose.

[StargeezerTim]

I think that is brilliant! Is your dslr modded? Think i might put a ha filter on my list and hope its not too late for Santa...

[Adam J]

There is a common misconception among CCD owners that you cant do narrow band with a DSLR...its a load of rubbish you can do it and it delivers a large relative performance increase. Now if you were to cool the DSLR as well you would get the same result or better with only 1.5 hours of integration. Nice image.

[Maximidius]

5 hours ago, wxsatuser said:

Very nice Ha Rose.

Thank you very much  

4 hours ago, StargeezerTim said:

I think that is brilliant! Is your dslr modded? Think i might put a ha filter on my list and hope its not too late for Santa...

Thank you  ...Yes my dslr is full spec modded and is cooled - all mods completed by........ME  

1 hour ago, Adam J said:

There is a common misconception among CCD owners that you cant do narrow band with a DSLR...its a load of rubbish you can do it and it delivers a large relative performance increase. Now if you were to cool the DSLR as well you would get the same result or better with only 1.5 hours of integration. Nice image.

Hey there, thanks  ...My camera was running at 0 deg C and will run much lower because it's cooled, but i tend to keep at the dew point, even with argon purging. I find that HA images with a DSLR are fun and relatively easy to process. But because mine still has the bayer matrix, the images lack the detailing of a mono CCD or mono DSLR image. This can be overcome to some degree with super pixel mode in DSS, plus drizzling the stack. The resulting image still has a crunchy feeling though, and requires some luminance NR. Mono version of the same set-up as mine ==== Fantastic and imho, at least as good as a lot of CCD devices..YMMV

[Adam J]

35 minutes ago, Maximidius said:

Thank you very much  

Thank you  ...Yes my dslr is full spec modded and is cooled - all mods completed by........ME  

Hey there, thanks  ...My camera was running at 0 deg C and will run much lower because it's cooled, but i tend to keep at the dew point, even with argon purging. I find that HA images with a DSLR are fun and relatively easy to process. But because mine still has the bayer matrix, the images lack the detailing of a mono CCD or mono DSLR image. This can be overcome to some degree with super pixel mode in DSS, plus drizzling the stack. The resulting image still has a crunchy feeling though, and requires some luminance NR. Mono version of the same set-up as mine ==== Fantastic and imho, at least as good as a lot of CCD devices..YMMV

I have a home made cool box its been running at -10c recently. Its completely air tight and with silica gell so it can run as cold as I like without any dew issues. It was the dew that made me go for a cold box as opposed to a cold finger design. I was able to make is extremely light and compact by using water cooling instead of air cooling for the TEC. I also have a 550D full spectrum. But until recently was using a 1000D. Have not gotten to use the 550D yet. It the temperature you quoted the Exif temp or via a temperature probe?

 

[Maximidius]

17 minutes ago, Adam J said:

I have a home made cool box its been running at -10c recently. Its completely air tight and with silica gell so it can run as cold as I like without any dew issues. It was the dew that made me go for a cold box as opposed to a cold finger design. I was able to make is extremely light and compact by using water cooling instead of air cooling for the TEC. I also have a 550D full spectrum. But until recently was using a 1000D. Have not gotten to use the 550D yet. It the temperature you quoted the Exif temp or via a temperature probe?

 

Looks like a quality bit of craftsmanship --- Cool  ...What's the total weight ? Mine is a cold finger design but with a difference. I have a cold finger that sits between the sensor and the board and is in contact with the back of the sensor as well as one on the heat sink frame on the front of the sensor, so it cool's really quickly...I can take mine down to -10 but it's really dependent on the ambient temperature. I can hold 0deg (in almost all weather here in japan, bearing in mind it's at 36 deg C and 98% RH in the summer ) with 900s on a continuous run as measured by a probe on the sensor. I don't really see a huge benefit in noise reduction below that though.  Humidity and temperature are major issues over here, everything gets absolutely dripping wet. It sucks and makes for a crappy atmosphere too

[Adam J]

22 minutes ago, Maximidius said:

Looks like a quality bit of craftsmanship --- Cool  ...What's the total weight ? Mine is a cold finger design but with a difference. I have a cold finger that sits between the sensor and the board and is in contact with the back of the sensor as well as one on the heat sink frame on the front of the sensor, so it cool's really quickly...I can take mine down to -10 but it's really dependent on the ambient temperature. I can hold 0deg (in almost all weather here in japan, bearing in mind it's at 36 deg C and 98% RH in the summer ) with 900s on a continuous run as measured by a probe on the sensor. I don't really see a huge benefit in noise reduction below that though.  Humidity and temperature are major issues over here, everything gets absolutely dripping wet. It sucks and makes for a crappy atmosphere too

Total is just a hair over 1.1kg so the box + coma corrector is about 600g and the DSLR about 500g depending on the model. When you consider that a full frame DSLR is about 900g its not so bad. Its made from laser cut ABS plastic, carbon fiber and neoprene insulation, so its quite lightweight. The focuser on my 130PDS easily handles it with no problems at all. Humidity is a problem in the uk too, but temperatures above 30c are not common even in summer.

I took a look at the back of the 550D as in theory I could add another TEC on a cold finger within the box itself acting like a two stage step down in temperature. But the gap is so small 0.3mm, that I thought that it would not work very efficiently, the advantage would be that you would get the sealed chamber (so no dew) and the cold finger in one. I am still considering getting some plate silver and making one though and if it works for you then it should work for me. The small 40mm fan on the back of the box sits directly over the sensor and moves cold air around the entire housing liniting sensor temperature rise above the internal temp of the cooler.

Its not so fast at cooling it takes about 1hour to drop the temperature by 20c and eventually drops it by 24c. But it normally takes me that long to setup the rest of the equipment anyway, so its not an issue if I start cooling first.

I asked about the Exif temp because I find it changes dramatically between cameras even after just a single 1/200 second exposure  taken straight after turn on the Exif temperature on my 550D reads about 7c higher than the Exif on my 1000D. So i think its actually a temperature calibration issue as it should not have had chance to warm up in that short a time and after a single short exposure.

[Scott]

3 hours ago, Adam J said:

There is a common misconception among CCD owners that you cant do narrow band with a DSLR...its a load of rubbish you can do it and it delivers a large relative performance increase. Now if you were to cool the DSLR as well you would get the same result or better with only 1.5 hours of integration. Nice image.

I don't believe there is any such misconception. just a knowledge that a colour camera (dslr or colour ccd) is not as efficient as a mono camera when using filters and a cooled camera is more efficient than a non-cooled one. 

So now that you know the camera is cooled are you assuming that uncooled would take much longer than 4 hrs? Doesn't sound too efficient does it

[Adam J]

15 minutes ago, Scott said:

I don't believe there is any such misconception. just a knowledge that a colour camera (dslr or colour ccd) is not as efficient as a mono camera when using filters and a cooled camera is more efficient than a non-cooled one. 

So now that you know the camera is cooled are you assuming that uncooled would take much longer than 4 hrs? Doesn't sound too efficient does it

Actually i am still a little surprised that it took 4hours given its cooled, but there are allot of other factors involved in imaging that are not related to the camera. I suspect that in this case a larger number of shorter exposures with dithering may perform better? But its very humid according to the OP so it is likely down to poor seeing and that no dark's, flats or bias were used. Either way its still an impressive image.

You actually just did the exact thing that I am talking about. Instead of focusing on the huge improvement to contrast and the deeper nebulosity bought out by using the narrow band filter on a DSLR you focused on the negative in that its not as efficient as a mono astro camera...well duh. The thing is that this common perspective leads many DSLR owners not to bothering with narrow band (perticually h-a) at all when it could be giving a step change improvement to their images.

Everyone knows that you are better off with mono CCD or CMOS for collecting narrow band data quickly, but in reality not all of us have the cash to go out and buy a 1.5k to 2.5k mono camera and in any case I find that having self modified a camera (Cooling, mono mod, IR mod...etc) I get a broader sense of satisfaction from the technical challenge and from seeing the improvements. It gives me the feeling that I have 'earned' the image more than if I just dropped 5000 pounds on the latest and greatest CCD. If i wanted to see the best image of the Rosetta nebula ever taken I am a few clicks away from a professional one using google. I could not do better than that even if I sold my house and spent it all on astro-imagin equipment. So given that non of us are ever beating a Hubble image, is this hobby not more about the challenge in achieving as much as possible with the equipment within our reach?

So I would ask yourself this, given two equal quality end images, which is more of an achievement the one taken over 20 hours using a cheap DSLR or one taken in 5 hours with a £5k Mono CCD? From whom did it take more skill and dedication?

I have seen some great images with un-cooled DSLR cameras using H-a filters, with cooling its much better. As for perceptions / misconceptions, I can find a ton of threads on here and other forums with people who have never tried using a narrow band filter with a DSLR saying that its not worth the money when in fact its gives exactly the same RELATIVE advantages and performance again it gives to a OSC CCD or Mono CCD its just that they were better cameras without the use of narrow band and so are still better after (although its questionable that an OSC CCD is much better than a cooled DSLR in my opinion mostly because of the lower native resolution meaning you take a much bigger hit from the reduction in resolution caused by using superpixel debayering).

[Scott]

8 minutes ago, Adam J said:

Actually i am still a little surprised that it took 4hours given its cooled, but there are allot of other factors involved in imaging that are not related to the camera. I suspect that in this case a larger number of shorter exposures with dithering may perform better? But its very humid according to the OP so it is likely down to poor seeing and that no dark's, flats or bias were used. Either way its still an impressive image.

You actually just did the exact thing that I am talking about. Instead of focusing on the huge improvement to contrast and the deeper nebulosity bought out by using the narrow band filter on a DSLR you focused on the negative in that its not as efficient as a mono astro camera...well duh. The thing is that this common perspective leads many DSLR owners not to bothering with narrow band (perticually h-a) at all when it could be giving a step change improvement to their images.

Everyone knows that you are better off with mono CCD or CMOS for collecting narrow band data quickly, but in reality not all of us have the cash to go out and buy a 1.5k to 2.5k mono camera and in any case I find that having self modified a camera (Cooling, mono mod, IR mod...etc) I get a broader sense of satisfaction from the technical challenge and from seeing the improvements. It gives me the feeling that I have 'earned' the image more than if I just dropped 5000 pounds on the latest and greatest CCD. If i wanted to see the best image of the Rosetta nebula ever taken I am a few clicks away from a professional one using google. I could not do better than that even if I sold my house and spent it all on astro-imagin equipment. So given that non of us are ever beating a Hubble image, is this hobby not more about the challenge in achieving as much as possible with the equipment within our reach?

So I would ask yourself this, given two equal quality end images, which is more of an achievement the one taken over 20 hours using a cheap DSLR or one taken in 5 hours with a £5k Mono CCD? From whom did it take more skill and dedication?

I have seen some great images with un-cooled DSLR cameras using H-a filters, with cooling its much better. As for perceptions / misconceptions, I can find a ton of threads on here and other forums with people who have never tried using a narrow band filter with a DSLR saying that its not worth the money when in fact its gives exactly the same RELATIVE advantages and performance again it gives to a OSC CCD or Mono CCD its just that they were better cameras without the use of narrow band and so are still better after (although its questionable that an OSC CCD is much better than a cooled DSLR in my opinion mostly because of the lower native resolution meaning you take a much bigger hit from the reduction in resolution caused by using superpixel debayering).

No!!!

Don't you dare try putting words in my mouth!!
Your opening line was " There is a common misconception among CCD owners that you cant do narrow band with a DSLR...its a load of rubbish you can do it and it delivers a large relative performance increase." My response was that there is no such misconception amoungst ccd owners. DSLR owners maybe but not ccd users. I also pointed out that a ccd owners know which is more efficient for narrowband. am I wrong? How many images do you see with ha/oiii/sii?

There is also no need for your smart mouth "Well duh" it's not neccessary.

I also think your talking about a £1.5k-£2.5k camera that turned into a £5k camera then one you have to sell your house for pointless. My sub £1k ccd is far cheaper than a bought cooled dslr (not everyone has the skill to do it themselves). so your money arguement doesn't wash.

Clearly you have not attempted to do a mosaic of even the rossette with a small chip CCD  otherwise you would know just how difficult and time consuming it is. 

I'm not here to argue the pro's and cons  of ccd / dslr. But I will also not tolerate people putting words in my mouth

Merry Christmas

[barkis]

Don't put your Image down Max.. it looks very nice indeed to me.
I am a big fan of Mono deep Sky Imagery, although this object always looks nice in it's pretty Red Dress.
Not sure if you intend to colour it, but I will still enjoy it if you do, I don't have any aversion to Colour, I just 
feel myself, that Mono has a more dramatic Impact somehow.
Good Job anyway .

[Adam J]

4 hours ago, Scott said:

No!!!

Don't you dare try putting words in my mouth!!
Your opening line was " There is a common misconception among CCD owners that you cant do narrow band with a DSLR...its a load of rubbish you can do it and it delivers a large relative performance increase." My response was that there is no such misconception amoungst ccd owners. DSLR owners maybe but not ccd users. I also pointed out that a ccd owners know which is more efficient for narrowband. am I wrong? How many images do you see with ha/oiii/sii?

There is also no need for your smart mouth "Well duh" it's not neccessary.

I also think your talking about a £1.5k-£2.5k camera that turned into a £5k camera then one you have to sell your house for pointless. My sub £1k ccd is far cheaper than a bought cooled dslr (not everyone has the skill to do it themselves). so your money arguement doesn't wash.

Clearly you have not attempted to do a mosaic of even the rossette with a small chip CCD  otherwise you would know just how difficult and time consuming it is. 

I'm not here to argue the pro's and cons  of ccd / dslr. But I will also not tolerate people putting words in my mouth

Merry Christmas

 

You are correct I should not have said "Well duh"

Beyond that, yes that was my opening line and ill stick by it. Lots of people will give you the advice that its not worth while using a DSLR with narrow band filters. I was given lots of advice to not bother trying it. But when I tried it, it worked great as evidenced by this image.

I suspect that i was given that advice because most people naturally purchase their first narrow band filters with their first mono camera and so never get around to trying narrow band with a DSLR and if they did it would be disappointing...but only by comparison to a mono CCD. To be fair there are not many people doing DSLR narrow band with cooled cameras. I have found it to work great with OIII, but I cant comment on SII as I dont own one. 

My point is that the effectiveness of narrow band filters with a DSLR has nothing to do with the your totally separate fact that they work best with a mono CCD. They still give you a massive contrast boost in a light polluted world.

I have done a DSLR narrow band bi-color mosaic of the Cygnus loop as that does not even fit into my FOV with a DSLR at 650mm...(ill see if i can dig it out), is there any difference in terms of process that i am not aware of? 

All of the above are my words, not yours, I do not mean to put words into your mouth, but it seemed to me that from your original comment you missed the point I was trying to make. My point was really simple, but ill reword it:

Irrespective of how much better it is to use a mono CCD, narrow band will give great results with a DSLR the best example being Ha-RGB. However the fact that it works better with a mono CCD clouds the issue for some people to the point that it generates an underlying tone that its not worth bothering with anything but a mono CCD.

I dont want to offend you at all, but how much better it works with a CCD is not much to do with how well it works with a DSLR.

I am curious about your CCD I have not seen any mono cooled CCD for under 1k perhaps that is one that might be within my reach in the future. I have nothing against using a CCD but I do derive satisfaction from my efforts in modifying my DSLR. I agree that buying a cooled DSLR off the shelf makes no sense. Again I am not here "to argue the pro's and cons  of ccd / dslr" either and if i was I would agree that a mono CCD wins be a huge margin, I am just here pointing out that using narrow band filters on a DSLR (even uncooled as the very modern DSLR's 760D / 6D / Sony A7s do well even without cooling) is valid when many will tell you it is not. I am not even claiming that you are saying that just that many people have and still do say that.

A genuine Merry Christmas to you too

 

[Maximidius]

7 hours ago, Adam J said:

Total is just a hair over 1.1kg so the box + coma corrector is about 600g and the DSLR about 500g depending on the model. When you consider that a full frame DSLR is about 900g its not so bad. Its made from laser cut ABS plastic, carbon fiber and neoprene insulation, so its quite lightweight. The focuser on my 130PDS easily handles it with no problems at all. Humidity is a problem in the uk too, but temperatures above 30c are not common even in summer.

I took a look at the back of the 550D as in theory I could add another TEC on a cold finger within the box itself acting like a two stage step down in temperature. But the gap is so small 0.3mm, that I thought that it would not work very efficiently, the advantage would be that you would get the sealed chamber (so no dew) and the cold finger in one. I am still considering getting some plate silver and making one though and if it works for you then it should work for me. The small 40mm fan on the back of the box sits directly over the sensor and moves cold air around the entire housing liniting sensor temperature rise above the internal temp of the cooler.

Its not so fast at cooling it takes about 1hour to drop the temperature by 20c and eventually drops it by 24c. But it normally takes me that long to setup the rest of the equipment anyway, so its not an issue if I start cooling first.

I asked about the Exif temp because I find it changes dramatically between cameras even after just a single 1/200 second exposure  taken straight after turn on the Exif temperature on my 550D reads about 7c higher than the Exif on my 1000D. So i think its actually a temperature calibration issue as it should not have had chance to warm up in that short a time and after a single short exposure.

That's pretty amazing considering the size of the box, i think you've done a fantastic job on keeping the weight down. 

The gap between the board and the sensor is indeed small. I didn't think a single cold finger would be particularly efficient on it's own hence, opting for a design that utilises the aluminium frame that sits on the front ot the sensor and a finger that sits on the back of the sensor. The two pieces are soldered together and the finger is cooled via a single tech with a largish heat sink and large fan. I have sealed the camera as much as possible and i can run it for a while without dewing issues but it's not 100% effective and there is little room for desiccants inside the camera. So i opted for argon purging which definitely helps with both cooling and dewing, but is not cost effective. Fortunately the valves i've installed on the camera for the argon purging can be used in a closed air circulation system. That's the next plan...  ....I'm not sure how reliable the Exif data is on my camera as i've changed the main board, but it's consistently around 5 deg above my sensor. With the cooling running the Exif temp values are stable. I did find that the temperature ramped up incredibly  quickly without cooling, but i never tested it on short exposures, neither have i completed any side by side tests on the exif values between various cameras, so i can't comment on the issues you noted regarding the temps between cameras and short exposure times. I wouldn't be surprised though. 

[Maximidius]

7 hours ago, Scott said:

I don't believe there is any such misconception. just a knowledge that a colour camera (dslr or colour ccd) is not as efficient as a mono camera when using filters and a cooled camera is more efficient than a non-cooled one. 

So now that you know the camera is cooled are you assuming that uncooled would take much longer than 4 hrs? Doesn't sound too efficient does it

Indeed you are correct and having completed some testing with a Nikon D80 on sensitivity, i can personally vouch for a significant increase in sensitivity and reduction in exposure time simply by removing the bayer matrix. The results where quite dramatic. Debayering a D80 is a simple process by comparison to the 550D in which the bayer material is much harder and significantly more troublesome to remove. That's a whole other thread though  

Regarding the efficacy of cooling this camera and the image quality vs time. It's an interesting point. We have to consider that these are 15 minute exposures with a DSLR... 900 second exposures with an uncooled 550D DSLR run in sequence with no pause other than dithering under the ambient conditions here, does lead to a massive amount of: noise production, banding, and hot pixels; of which i have found cannot be completely compensated for via calibration files and leads to major image degradation. 600S is possible in the winter but still has resulting issues, in the summer time, here; no chance! So getting a DSLR to 15 min exposures (i'm confident i could do 30mins) with no calibration files and with good results i consider a major achievement under the conditions here in Japan. So in my defence, i would say that while compared to a cooled colour CCD it may not be as good. Compared to the same uncooled camera under the same conditions with no calibration files, it's pretty darn incredible. And if this were to be debayered and the HA image produced ander full illumination and the resulting maximum resolution, well....I've no doubt that it would be at least comparable and better to CCDs of the same price range ....uuuurm that's £250 in total  So i can't complain.

[Maximidius]

4 hours ago, barkis said:

Don't put your Image down Max.. it looks very nice indeed to me.
I am a big fan of Mono deep Sky Imagery, although this object always looks nice in it's pretty Red Dress.
Not sure if you intend to colour it, but I will still enjoy it if you do, I don't have any aversion to Colour, I just 
feel myself, that Mono has a more dramatic Impact somehow.
Good Job anyway .

Thank you so much  

I like mono too, and imaging with an HA filter affords me the opportunity to image from places where i simply couldn't get the depth of these images in colour. I have a 12nm OIII filter which i haven't used yet, i intend to collect some data on the rosette and try a bi-colour DSLR NB image. I'm sure it won't match the quality of a mono or CCD version, but it's fun nevertheless. I agree though, mono images do have a dramatic impact.   ...Thanks again  

[Maximidius]

Reduced the center stars 

 

[Stu]

8 hours ago, Adam J said:

 

You are correct I should not have said "Well duh"

Beyond that, yes that was my opening line and ill stick by it. Lots of people will give you the advice that its not worth while using a DSLR with narrow band filters. I was given lots of advice to not bother trying it. But when I tried it, it worked great as evidenced by this image.

I suspect that i was given that advice because most people naturally purchase their first narrow band filters with their first mono camera and so never get around to trying narrow band with a DSLR and if they did it would be disappointing...but only by comparison to a mono CCD. To be fair there are not many people doing DSLR narrow band with cooled cameras. I have found it to work great with OIII, but I cant comment on SII as I dont own one. 

My point is that the effectiveness of narrow band filters with a DSLR has nothing to do with the your totally separate fact that they work best with a mono CCD. They still give you a massive contrast boost in a light polluted world.

I have done a DSLR narrow band bi-color mosaic of the Cygnus loop as that does not even fit into my FOV with a DSLR at 650mm...(ill see if i can dig it out), is there any difference in terms of process that i am not aware of? 

All of the above are my words, not yours, I do not mean to put words into your mouth, but it seemed to me that from your original comment you missed the point I was trying to make. My point was really simple, but ill reword it:

Irrespective of how much better it is to use a mono CCD, narrow band will give great results with a DSLR the best example being Ha-RGB. However the fact that it works better with a mono CCD clouds the issue for some people to the point that it generates an underlying tone that its not worth bothering with anything but a mono CCD.

I dont want to offend you at all, but how much better it works with a CCD is not much to do with how well it works with a DSLR.

I am curious about your CCD I have not seen any mono cooled CCD for under 1k perhaps that is one that might be within my reach in the future. I have nothing against using a CCD but I do derive satisfaction from my efforts in modifying my DSLR. I agree that buying a cooled DSLR off the shelf makes no sense. Again I am not here "to argue the pro's and cons  of ccd / dslr" either and if i was I would agree that a mono CCD wins be a huge margin, I am just here pointing out that using narrow band filters on a DSLR (even uncooled as the very modern DSLR's 760D / 6D / Sony A7s do well even without cooling) is valid when many will tell you it is not. I am not even claiming that you are saying that just that many people have and still do say that.

A genuine Merry Christmas to you too

 

Great reply Adam.

A very happy Christmas to you. Enjoy!

[Adam J]

6 hours ago, Maximidius said:

That's pretty amazing considering the size of the box, i think you've done a fantastic job on keeping the weight down. 

The gap between the board and the sensor is indeed small. I didn't think a single cold finger would be particularly efficient on it's own hence, opting for a design that utilises the aluminium frame that sits on the front ot the sensor and a finger that sits on the back of the sensor. The two pieces are soldered together and the finger is cooled via a single tech with a largish heat sink and large fan. I have sealed the camera as much as possible and i can run it for a while without dewing issues but it's not 100% effective and there is little room for desiccants inside the camera. So i opted for argon purging which definitely helps with both cooling and dewing, but is not cost effective. Fortunately the valves i've installed on the camera for the argon purging can be used in a closed air circulation system. That's the next plan...  ....I'm not sure how reliable the Exif data is on my camera as i've changed the main board, but it's consistently around 5 deg above my sensor. With the cooling running the Exif temp values are stable. I did find that the temperature ramped up incredibly  quickly without cooling, but i never tested it on short exposures, neither have i completed any side by side tests on the exif values between various cameras, so i can't comment on the issues you noted regarding the temps between cameras and short exposure times. I wouldn't be surprised though. 

Thanks the main contributor to the weight in most cool box designs is the hot side heat sink and fan...at least if you want to use a high power TEC. Using the water block massivly reduces weight. I just connect it to the garden hose and trickle water through it. I dont bother with a radiator. I would be interested in seeing a picture of your setup if you have the time.

Actually thinking about it removing the LCD and Battery probably saves a good 100g or more.

[Scott]

My point was there is no such misconception re ccd imagers.

I'm done here

[ollypenrice]

I like the image and think it very creditable on all counts. I do, though, spend lots of time on here and have not come across CCD imagers claiming that you can't do NB with a DSLR. I join Scott in saying, in effect, that the sentence, 'There is a common misconception among CCD owners that you cant do narrow band with a DSLR...its a load of rubbish you can do it and it delivers a large relative performance increase' creates a straw man. I can't think of a single CCD imager I know, and given my job I know quite a few, who would say that. What we would, and often do, say is that in Ha you are running on only a quarter of your pixels with the loss of signal and resolution commensurate with that. The resolution may matter little given the small pixel size of modern DSLRs. We might also say that Ha will probably work best of the NB filters. How does SII work through a Bayer Matrix? I don't know.

So good image but incorrect assertion that CCD imagers commonly talk rubbish about Ha in DSLRs. I don't believe they do.

Olly

[Stu]

1 hour ago, ollypenrice said:

I like the image and think it very creditable on all counts. I do, though, spend lots of time on here and have not come across CCD imagers claiming that you can't do NB with a DSLR. I join Scott in saying, in effect, that the sentence, 'There is a common misconception among CCD owners that you cant do narrow band with a DSLR...its a load of rubbish you can do it and it delivers a large relative performance increase' creates a straw man. I can't think of a single CCD imager I know, and given my job I know quite a few, who would say that. What we would, and often do, say is that in Ha you are running on only a quarter of your pixels with the loss of signal and resolution commensurate with that. The resolution may matter little given the small pixel size of modern DSLRs. We might also say that Ha will probably work best of the NB filters. How does SII work through a Bayer Matrix? I don't know.

So good image but incorrect assertion that CCD imagers commonly talk rubbish about Ha in DSLRs. I don't believe they do.

Olly

I think there is a large degree of 'missing the point' here. The point was nothing to do with CCD vs DSLR or any such thing, it was simply that DSLR imagers should not discount NB imaging and the benefits it can bring under LP conditions if they are not yet ready to move up to CCD. It was a very simple point which was misinterpreted.

Happy Christmas all.

[toxic]

great image Max

 

[ollypenrice]

42 minutes ago, Stu said:

I think there is a large degree of 'missing the point' here. The point was nothing to do with CCD vs DSLR or any such thing, it was simply that DSLR imagers should not discount NB imaging and the benefits it can bring under LP conditions if they are not yet ready to move up to CCD. It was a very simple point which was misinterpreted.

Happy Christmas all.

I'm responding only to AdamJ's incorrect assertion, 

'There is a common misconception among CCD owners that you cant do narrow band with a DSLR.'

This misconception does not exist. We CCD imagers know perfectly well that you can do NB, and particularly Ha, with a DSLR and we frequently say so on here. AdamJ chose to add that this opinion, which is not held by CCD imagers, is 'a load of rubbish.' What is really a load of rubbish is the claim that we hold this opinion when we don't - but, hey, let's not make a big deal of this.

Very nice Rosette from the OP.

Olly

[Stu]

17 minutes ago, ollypenrice said:

I'm responding only to AdamJ's incorrect assertion, 

'There is a common misconception among CCD owners that you cant do narrow band with a DSLR.'

This misconception does not exist. We CCD imagers know perfectly well that you can do NB, and particularly Ha, with a DSLR and we frequently say so on here. AdamJ chose to add that this opinion, which is not held by CCD imagers, is 'a load of rubbish.' What is really a load of rubbish is the claim that we hold this opinion when we don't - but, hey, let's not make a big deal of this.

Very nice Rosette from the OP.

Olly

I was responding to the later messages Olly.

I can only say that I think Adam J is doing his level best to respond in a calm and measured way notwithsatnding a few unnecessary comments which he has corrected. I don't believe it requires such a 'robust' response and think that it is others that are making the big deal about it. I really don't think there is much to disagree about here, everyone seems to agree about the relative benefits of DSLR/CCD and NB so let's leave it at that shall we?