428EX or 460EX as an upgrade

[earth titan]

Hi folks.

I've been using my 314 for about 18 months now and really pleased with the results I can get with my 80mm APO, especially as an intro to mono CCD. The only drawback is the resolution. I always find the images are a little 'blocky' and I'm looking to upgrade toward the end of the year to overcome this issue. My main interest is in galaxies and clusters so resolution is important as I tend to magnify the pictures I get.

I'm sticking with Atik as I've been so impressed with connectivity, performance and the capture software, so I've got 2 options in mind. These are the 428EX and the 460EX. 

I'm tending toward the 460 (despite the expense) as I think it should give a wider field of view and the same resolution as the 428. This would overcome some of the issues I have currently, where some of the larger galaxies just don't quite fit in the FOV. I have however, seen some disappointing reviews of the 460 when compared to the 314.

I've been looking at the camera specs and they all use Sony sensors (which seem well regarded and certainly the 314 is brilliant) so I'm looking for some more informed opinions than mine and hopefully some experiences.

Q1

Does anyone have the sensor size for the 428EX? Atik seem to quote the size for the 460, but not the 428.

Q2

I'm guessing, based on the data I can find, that the resolution of the 428 and 460 will effectively be the same (image for image), with the 460 having a wider field of view. Is this correct?

Q3

Both cameras will give me better resolution than the current 314?

Q4

Any warts and all reviews of both out there?

Data found as follows:

314

Horizontal Resolution: 1392 pixels

Vertical Resolution: 1040 pixels

Pixel Size: 6.45 µM x 6.45 µM

428EX

Horizontal Resolution : 1932 pixels

Vertical Resolution : 1452 pixels

Pixel Size : 4.54x4.54 μm

460EX

CCD Image area : 12.49mm Horizontal x 9.99mm Vertical (15.97mm diagonal)

Horizontal Resolution : 2750 pixels

Vertical Resolution : 2200 pixels

Pixel Size : 4.54x4.54 μm

[GuillermoBarrancos]

These are the specs of the 428EX including sensor size:

-- Sensor Type ... Sony ICX674 - 8,8x6,5mm
-- Resolution ... 1932x1452 pixels / 2,8 MP
-- Pixel Size ... 4.54 x 4.54µm
-- ADC ... 16 bit
-- Readout noise ... Typical 4e-
-- Interface ... Mini-USB 2.0
-- Power ... 12V DC, 1A
-- Cooler ... Regulated to -30°
-- Weight ... 400g
-- Dimensions ... 60mm diameter (round) - Lengh 121mm
-- Distance from the T2 thread to the sensor ... 13mm

Both 428EX and 460EX are exactly the same in specs, just that the sensor is twice the size with double amount of pixels.

So the 460EX will have twice the FOV as the 428EX.

Also to consider. When imaging at long focal length, the 460EX will have the advantage of 2x2 binning with a FOV as the 428EX, while 2x2 binning with the 428EX will diminish your FOV quite drastically.

The Atik 460EXM is also on my shortlist of possible Mono CCD camera to buy, alongside the Moravian G2-8300 and G2-4000. Gonna be a tough choice. All three are great cameras. /sigh

If you plan on imaging with your C9.25, you might want to consider a sensor with larger pixels, like the Atik 4000MLE. Tho the Moravian G2-4000 is better priced, has 2-stage peltier cooling (like the much more expensive Atik 4000M) and better read Electronics.

The Kodak KAI 04022 is a square sensor with 2k by 2k pixels. So when binning you still have a respectable 1k by 1k pixels FOV. But with a much better arcsec pixel ratio on long focal lengths. Most importantly you can continue to use 1,25 inch filters with this large format sensor!

Resolution 2056 (H) × 2062 (V) pixels

Pixel size 7.4 μm (H) × 7.4 μm (V)

Imaging area 15.2 mm (H) × 15.3 mm (V)

Full well capacity ~40,000 e^-

Dark current 40 e^-/s/pixel at 40 °C

Dark current 0.8 e^-/s/pixel at 0 °C

Dark signal doubling 6 °C

[earth titan]

Cheers for the data.

As I suspected then - the 428 is the same FOV as my much loved 314 but at about twice the resolution. Not sure I can justify the 460 (or can I? )

I think the 428 is the next logical step for me. Still runs with 1.25" filters, runs the same Atik software and I know that the Atik kit works.

[swag72]

Having used the 460, I think it makes sense (I upgraded from the 314L+ also) - You can crop your image to the same size as the 428 and get exactly the same fov or you can leave it uncropped and get a larger field of view. That way you can image larger stuff without resorting so much to mosaics, which you will definitely be doing with the 428.

To my mind the image resolution will be the same with both, you can crop the 460 down to match the 428, but you can't make the 428 bigger - No brainer in my opinion.

[GuillermoBarrancos]

Cheers for the data.

As I suspected then - the 428 is the same FOV as my much loved 314 but at about twice the resolution. Not sure I can justify the 460 (or can I? )

I think the 428 is the next logical step for me. Still runs with 1.25" filters, runs the same Atik software and I know that the Atik kit works.

You have to understand that both 428EX and 460EX have much smaller pixels than the 314L+.

With Your C9.25 SCT you will be imaging at 0,4 arcsec pixels in 1x1 bin mode. So you end up in 2x2 bin mode With either 428EX and 460EX. With the 460EX in 2x2 bin you still have a respectable FOV similar to the 314L+, while With the 428EX in 2x2 bin mode you will have half the FOV of Your 314L+.

Keep that in mind.  Long focal lengths benifit from cameras with larger pixels.

[earth titan]

My main imaging rig, won't be the C9.25, so not too many worries there. My life is too short to spend too much time on the SCT imaging route - although I shall have a go.

Sarah,

What is your opinion of the 460? I remeber reading posts when you first got it, that seemed to suggest you were a little underwhelmed?

[swag72]

Perhaps I was - I can't remember back then!! - But it really is a stonking little camera. I have been really pleased with it. It worked well on the short focal length 329mm of the Tak and binned on the C9.25 it works well too. If I came across as underwhelmed it was probably more a symptom of change!

Go for the 460, you'll not be disappointed I'm sure.

Have you considered something other than an Atik?

[earth titan]

Perhaps I was - I can't remember back then!! - But it really is a stonking little camera. I have been really pleased with it. It worked well on the short focal length 329mm of the Tak and binned on the C9.25 it works well too. If I came across as underwhelmed it was probably more a symptom of change!

Go for the 460, you'll not be disappointed I'm sure.

Have you considered something other than an Atik?

Thanks Sarah.

May have to stretch the budget then !  

I've not really considered anything other than Atik, on the basis of familiarity really and nothing else. I like the capture software and as yet, the 314 has worked every time I asked it. Also FLO provide the best service I know of - so if something goes wrong it will get fixed.

[swag72]

QSI are worth a look - They are an excellent brand, a step up in quality from what I understand - Mine's on order!

[earth titan]

QSI are worth a look - They are an excellent brand, a step up in quality from what I understand - Mine's on order!

Which are you ordering?

[lensman57]

If funds allow get the 460, there used to be about £750.00 difference in price between the two but the 460 has been reduced in price, probably to make the Atik One  competative in price as it has the same chip as the 460 but with better cooling and filter wheel. With 6mp of resolution and a larger sensor you will have the option of binning or cropping off the unwanted area. remember that u can always crop but not add on umless u wish to do mosaics. The pixel size is smaller than the 314l+ but I can not detect any real practical loss in dynamic range. It also has much better sensitivity in the Ha region.

A.G

[mbrickley]

I recently measured the performance of the 460 (see posts on here on 460ex for photometry). In conclusion my sample at least is highly linear throughout the whole adu range and has negligible noise both dark current and read noise. It really is a brilliant camera. I use mine for both photometry and also looking for dim galaxies and measuring them. It's done very well with both a 4 inch and 5 inch scope but I agree that it will have much smaller pixels than desirable with your sct, even binned 2x2 it's pushing it.

You might also look at the new atik one which has a filter integrated but has same chip as 460ex and is on a special introductory offer at the moment.

Mark

[GuillermoBarrancos]

I recently measured the performance of the 460 (see posts on here on 460ex for photometry). In conclusion my sample at least is highly linear throughout the whole adu range and has negligible noise both dark current and read noise. It really is a brilliant camera. I use mine for both photometry and also looking for dim galaxies and measuring them. It's done very well with both a 4 inch and 5 inch scope but I agree that it will have much smaller pixels than desirable with your sct, even binned 2x2 it's pushing it.

You might also look at the new atik one which has a filter integrated but has same chip as 460ex and is on a special introductory offer at the moment.

Mark

I found that an very interesting topic you posted a short while ago.

But what about the Anti-Blooming gate on the Atik 428 and 460 cameras? I thought that for acurate messurements it's best to use a CCD camera without Anti-Blooming gate?

[earth titan]

It really is a brilliant camera. I use mine for both photometry and also looking for dim galaxies and measuring them. It's done very well with both a 4 inch and 5 inch scope but I agree that it will have much smaller pixels than desirable with your sct, even binned 2x2 it's pushing it.

Mark

Thanks Mark. Looking as though everyone agrees - the 460 is extremely good.

Shan't often be using on the SCT, so no worries there.

[ollypenrice]

Guilliermo, binning doesn't reduce the FOV, it reduces the final image size.

'Resolution' is an odd word because it has far too many meanings! For me resolution, in discussing sensors, means pixel size and nothing else.

At long focal lengths the larger chip would be well worth it, opening up more targets and allowing you to bin while still retaining a respectable final image size. I would certainly go for the 460 myself.

I've never owned one but I've processed lots of images taken with them and have always been impressed. The camera is sensitive and clean. I don't see better cooling as all that important on the Sony chips used in northern climates but cooler is always better, I suppose. I really like the camera. I don't know if you saw this 460 Triplet taken at F5.3? http://stargazerslounge.com/topic/214878-leo-triplet-tidal-tail-in-2-hours/

The tidal tail came out like this in a paltry 4x30 minutes of L. This strikes me as bordering on the supernatural! It's better than I obtained in three times that exposure length at F5 on a Kodak and if there were a prize for the best tail in the shortest time I think Shine On would win it!

Olly

[GuillermoBarrancos]

Guilliermo, binning doesn't reduce the FOV, it reduces the final image size.

My bad in wording it correctly! You are ofcourse right!   You cut the resolution in half with 2x2 binning, while ofcourse retaining the same FOV. The end result will look two times smaller on the PC screen.

'Resolution' is an odd word because it has far too many meanings! For me resolution, in discussing sensors, means pixel size and nothing else.

I am an IT consultant for living, so that´s the mess up With my wording when it comes to resolution and FOV. I am just too deep into the digital realm of Things.

At long focal lengths the larger chip would be well worth it, opening up more targets and allowing you to bin while still retaining a respectable final image size. I would certainly go for the 460 myself.

I've never owned one but I've processed lots of images taken with them and have always been impressed. The camera is sensitive and clean. I don't see better cooling as all that important on the Sony chips used in northern climates but cooler is always better, I suppose. I really like the camera. I don't know if you saw this 460 Triplet taken at F5.3? http://stargazerslounge.com/topic/214878-leo-triplet-tidal-tail-in-2-hours/

The tidal tail came out like this in a paltry 4x30 minutes of L. This strikes me as bordering on the supernatural! It's better than I obtained in three times that exposure length at F5 on a Kodak and if there were a prize for the best tail in the shortest time I think Shine On would win it!

I guess it´s on these kind of targets where the much higher QE of the Atik 428 / 460 really shines.

Olly

See my response in red.

The Atik 460EX is really high on my own list of possible CCD candidates, next to the Moravian G2-8300 and G2-4000.

What still holds me back a little tho, is the image depth of the images I have seen so far from both the 428EX and 460EX.

They look rather flat (2D like) compared to images taken with for example the KAF8300 and KAI 04022 for example, which show much more depth (3D like).

Maybe it´s just me? I don´t know.

Guillermo

[ollypenrice]

See my response in red.

The Atik 460EX is really high on my own list of possible CCD candidates, next to the Moravian G2-8300 and G2-4000.

What still holds me back a little tho, is the image depth of the images I have seen so far from both the 428EX and 460EX.

They look rather flat (2D like) compared to images taken with for example the KAF8300 and KAI 04022 for example, which show much more depth (3D like).

Maybe it´s just me? I don´t know.

Guillermo

Yes, you might be onto something regarding the depth.

Olly

[earth titan]

Thanks chaps. Much of the debate is way over my head but the thought that the 460 might be all the camera I need (until the next upgrade ) is brilliant news!

I think sacrificing a bit of depth, for speed of capture, is pretty vital under UK skies. The Tail looks brilliant - something to aspire to.

[GuillermoBarrancos]

Thanks chaps. Much of the debate is way over my head but the thought that the 460 might be all the camera I need (until the next upgrade ) is brilliant news!

I think sacrificing a bit of depth, for speed of capture, is pretty vital under UK skies. The Tail looks brilliant - something to aspire to.

The ICX694 in the Atik 460ex is a fantastic sensor! You will definitely not regret it! I still might end up buying it myself in the end.

I am just still a bit torn between the 460ex and the G2-8300 / G2-4000 due to the "depth" thing.

[mbrickley]

mbrickley, on 23 Apr 2014 - 3:29 PM, said:

I recently measured the performance of the 460 (see posts on here on 460ex for photometry). In conclusion my sample at least is highly linear throughout the whole adu range and has negligible noise both dark current and read noise. It really is a brilliant camera. I use mine for both photometry and also looking for dim galaxies and measuring them. It's done very well with both a 4 inch and 5 inch scope but I agree that it will have much smaller pixels than desirable with your sct, even binned 2x2 it's pushing it.

You might also look at the new atik one which has a filter integrated but has same chip as 460ex and is on a special introductory offer at the moment.

Mark

I found that an very interesting topic you posted a short while ago.

But what about the Anti-Blooming gate on the Atik 428 and 460 cameras? I thought that for acurate messurements it's best to use a CCD camera without Anti-Blooming gate?

Hi

NABG are in theory entirely linear over their range provided you dont saturate the CCD, at which point of course the max adu value  of 65k doesnt increase further with additonal photons. Its also true that ABG cameras become non linear near to the point where the physical electron wells on the chip are full with electrons. Its important to note however that the relationship between the maximum readout adu (when the pixel reads 65,500) and the physical nuumber of electrons in the well at that point is not a fixed relationship but set by the manufacturer of the camera by setting the gain.

What, I think, Atik have done is set the gain such that the maximum adu value occurs when the well has 17k or so electrons in it (see my second post) whereas the chip full well depth occurs at 20k electrons or so. This means that although in theory you lose some potential well depth (ie the final 3k of electrons filling a given well  dont increase the adu), you also get a camera that is linear across its whole adu range because the top 10% or so of well depth that in non linear due to the abg is never measured. This makes the camera very linear for photometry or any other application where linearity is useful.

Whats the disadvantage of not utilising the full well depth, well in theory because your maximum electron signal is lower (17k plays 20k) while the read noise remains the same so your SNR is lower and, in theory, your image is noisier. My second post shows why this matters very little with the 460.... the noise is extremely low so the real effect of not using the well depth to the entire extent is negligible.

It seems to me that Atik have done a stirling job of maximising the utility of the 460 and I think it is probably my favourite camera. I have a NABG st10 as well and I fijnd the 460ex easier to use because its lighter and needs less complex power and the images are certainly less noisy. Hope this is helpful

Mark

[lensman57]

The ICX694 in the Atik 460ex is a fantastic sensor! You will definitely not regret it! I still might end up buying it myself in the end.

I am just still a bit torn between the 460ex and the G2-8300 / G2-4000 due to the "depth" thing.

Hi GB,

Very interesting point that you have raised with the Depth of the Atik 428 and 460, but just to clarify the matter I had the impression that you were refering to the two or three dimensional feeling of the captures, surely a subjective matter, rather than the issues  of the use of  ABG or the  well depth of the sensors. If so,  I tend to agree with you to some extent as I too have noticed a rather flat look to the images produced with 428 and 460 but TBH I always put it down to the use of Mirrors in the scopes, be it a Newt, a Schmidt Newt or their varients. I find that my eyes find more three dimensionality if a decent Apo had been usein the captures.

Regards,

A.G

[GuillermoBarrancos]

Hi GB,

Very interesting point that you have raised with the Depth of the Atik 428 and 460, but just to clarify the matter I had the impression that you were refering to the two or three dimensional feeling of the captures, surely a subjective matter, rather than the issues  of the use of  ABG or the  well depth of the sensors. If so,  I tend to agree with you to some extent as I too have noticed a rather flat look to the images produced with 428 and 460 but TBH I always put it down to the use of Mirrors in the scopes, be it a Newt, a Schmidt Newt or their varients. I find that my eyes find more three dimensionality if a decent Apo had been usein the captures.

Regards,

A.G

Yes I did not mean the ABG. As the Kodak sensors like the KAF8300 and KAI 04022 also have an ABG. I indeed mean the Three dimensional feeling of the captures.

I get a much more Three dimensional feel of images taken With the mentioned Kodak sensors, then With Sony's New sensors used in the Atik 428ex and 460ex.

But you also raise an interesting point regarding mirrors used in SCT's, Newts, etc. I remember now having read some discussions before that SCT's tend to produce more flat images compared to other optical designs and that refractors indeed produce the best depth.

Tho I have seen a lot of fantastic images taken with Ritchy-Cretien Scopes that do show Depth tho. So maybe it's not the Mirror itself per se, but more the use of a corrector plate? Some interesting stuff to dig into for sure. 

Ironically, the vast majority and the best quality images taken with the 460 on Astrobin so far are all with SCT's at the moment. /sigh (have to Plough through the internet a bit harder later and see if I can find some high quality 460ex images taken with an APO)

Maybe we can ask Sara (or someone else with an Atik 460 and APO) to capture and process some images with the Atik 460 and APO and see if those images provide more depth.

If that ends up being the case, then that would put matters definitely to rest and the 460ex will be back on position number 1 on my CCD list. As I really like the high and broad QE curve of these sensors! 

[lensman57]

Yes I did not mean the ABG. As the Kodak sensors like the KAF8300 and KAI 04022 also have an ABG. I indeed mean the Three dimensional feeling of the captures.

I get a much more Three dimensional feel of images taken With the mentioned Kodak sensors, then With Sony's New sensors used in the Atik 428ex and 460ex.

But you also raise an interesting point regarding mirrors used in SCT's, Newts, etc. I remember now having read some discussions before that SCT's tend to produce more flat images compared to other optical designs and that refractors indeed produce the best depth.

Tho I have seen a lot of fantastic images taken with Ritchy-Cretien Scopes that do show Depth tho. So maybe it's not the Mirror itself per se, but more the use of a corrector plate? Some interesting stuff to dig into for sure. 

Ironically, the vast majority and the best quality images taken with the 460 on Astrobin so far are all with SCT's at the moment. /sigh (have to Plough through the internet a bit harder later and see if I can find some high quality 460ex images taken with an APO)

Maybe we can ask Sara (or someone else with an Atik 460 and APO) to capture and process some images with the Atik 460 and APO and see if those images provide more depth.

If that ends up being the case, then that would put matters definitely to rest and the 460ex will be back on position number 1 on my CCD list. As I really like the high and broad QE curve of these sensors! 

Hi GB,

I really like my 428EXC, very sensitive and my  314L+ is not bad for Mono either. What we need is a Mono ICX 6 series  sensor in  DX size. Now that would be a sensor to have. 

Regards,

A.G

[GuillermoBarrancos]

Hi GB,

I really like my 428EXC, very sensitive and my  314L+ is not bad for Mono either. What we need is a Mono ICX 6 series  sensor in  DX size. Now that would be a sensor to have. 

Regards,

A.G

And more than likely the price to match too lol.