Hi All,
I was thinking about getting an EOS400D with its 10 Mp. sensor (I now have a EOS300D-6.3 Mp.) but reading an in depth comparison of these two cameras it would seem that the EOS350D is the better Camera, at least for Astrophotography, the 10 Mp. is an attraction, and the absence of amplifier glow an accomplishment, but the thermal noise is higher, and the Red sensitivity lower by some 20%, I would appreciate any comments or feedback as regards the performance of the EOS400D from anyone who has researched this Camera, my source is: http://www.astrosurf.org/buil/400d/400d.htm
It is however a Google translation from the original French document, which leaves a lot to be desired.
Hello Jim, I had a 350d for a while before it took a swim in the ocean, the camera performed great on almost everything i targeted.
I now have a 400d and find it even better, higher resoution, that wouldnt make much of a difference but helps in larger print size, i heard by only an inch or two, 350d, 3456 x 2304, and the 400d 3888 x 2592 Max resolution.
Sensor cleaner, a good idea, and also the dust removal software, for those stubborn motes, you basically take a pic of a flat white wall, or screen and the camera records it and uses it to remove the dust from the image through the software, i haven't tried it yet, but it seems like a great idea, saves you from trying to clone out dust on a decent pic.
If you had a 350d, it wouldn't really be worth upgrading to the 400d, in my opinion, but i would buy the 400d in a flash over the 350d if i was looking at purchasing a dig-cam.
Regarding noise, have a look around the net at comparisons, both cameras are almost equal in high iso noise results, at least from the tests i have seen, as far as lower sensitivity, i am not too sure, i will dig out some pics taken from my backyard wth the 350d and match the settings and take the same image with the 400d.
Hi Trevor & John,
Many thanks for your comments and views on the subject, All in all the 10 Mp. size is the big item, the Thermal noise although greater on the 400D (at ISO-400 + ISO-800 in addition to ISO-1600) is only a few % moreso, and the temperature difference between summer and winter makes more difference in the noise level by far than this, and looking at the latest posts in this forum re Cooled DSLRs (Central DS Co.) thermal noise wont be a worry anyway.
just watch it with the 350d's secondhand - i bought mine new a year and a half ago roughly, with trade-ins (mamiya medium format and lenses), by the time I got around to dark-sky astro imaging with the 350d, it was past the warranty stage, so i couldnt fo anything about it, but i have one of the infamous 'striped' chips that were around at one point (see my images to see what I mean - altho normal terrestial photos are fine) so when you stretch and enhance a long exposure astro image you see background striping! gggrrr - so I will now have to definately get a 400D in the near future.
Hi Fringe-Dweller,
Well thats interesting news, I did have some thoughts of getting an EOS350D off E-Bay, but if there are DUDs amongst them Ill have a rethink, were these just one batch, S/Ns notable, or can this problem be in any 350D, Ive never heard of this problem with the 300Ds, Ill bet you are browned off with finding out about the 350Ds CMOS chips are faulty, have you contacted CANON, Im certain they would replace the Chip, Makes one wonder if the 400Ds might come up with problems.
when i noticed it first, I remembered reading on yahoo digital_astro way back, people complaining of the banding, and being advised to quickly take them back while under warranty, as there was a bad batch, but canon will replace no problems - it seemed to me (i could be wrong) to be common knowledge to the members there (I havent been following digital_astro for a while now - so dont know if there was anything further on the subject?) for all i know the banding is normal? and is dealt with by quality raw darks (which i keep forgetting to do) i have asked here before what it is, and recieved no answer at the time - i would dearly love to know if its 'normal' or in fact faulty - which is it?
and the banding is present in every single longish exposure - no matter what the iso, as soon as you stretch it ..whamo! there is it is! and yes i am definately browned off - especially after reading all the glowing support of digital over film prior to buying it - phooee - for an an old film fan, this was further proof of the diabolicalness of digital (ie: would have to buy and start using a pc for one thing )
I didnt plan to use the 350d for astro work in the dark at the time, just twilight and normal daytime stuff, at which it does a superb job btw! normal camera usage would not show it up, so a seller wouldnt even know i guess
when i noticed it first, I remembered reading on yahoo digital_astro way back, people complaining of the banding, and being advised to quickly take them back while under warranty, as there was a bad batch, but canon will replace no problems - it seemed to me (i could be wrong) to be common knowledge to the members there (I havent been following digital_astro for a while now - so dont know if there was anything further on the subject?) for all i know the banding is normal? and is dealt with by quality raw darks (which i keep forgetting to do) i have asked here before what it is, and recieved no answer at the time - i would dearly love to know if its 'normal' or in fact faulty - which is it?
I've had a look at your image Kearn.
To me it's a lovely image and see nothing wrong.
It's at ISO 1600 so it'll be a bit grainy but I see no banding, only the lovely bands of the comet's tail.
Do you have any other examples because it's hard to see in this example.
I hope you don't mind Kearn, I had a very quick play with your image of the comet.
Like I said I don't notice anything unusual unless I misunderstood what you were describing.
no I dont mind at all, wow! nice work RB!
I am guessing here/ but you have run it through a noise reduction proggy and giving it a darkframe? and darkened it a bit mebbe too. its kinda lost a bit of the tail detail, but is certainly looking heaps better :-) not complaining tho
i expected the noise at that iso, naturally np, but the banding was definitely there before, unless that is all part of the same noise thing, but its at all iso's, if stretched.
here is a cropped close up section of same pic, using jpg only and stretched and sharpened to bring it out hopefully (i did once think that it was a jpg issue, and tried a converted to 16bit TIFF of same pic, it definately reduces it (the banding), but its still there to a certain extent.)
the banding isnt full on obvious I guess, its bit faint, i should of said before, but its still there.
i appreciate you taking the time to help me out here Andrew! I wish it was all in my imagination
Hi All,
Well thanks for all the comments & ideas, FRINGE_Dweller- I can see the banding you mean, ISO-1600 is a touchy setting for Astrophotograpy ive found, even after DF removal results are never as good as when ISO 800 or less is used (Im not certain what goes on in the Camera when one changes the ISO setting, weather is just pixell binning or something else- does anyone know??) As regards your banding on the EOS350 it must be a problem if it has been brought up on the "Yahoo Forum" by others, It dosent look real bad to me, did you do a DF subtraction in this picture, and does a DF subtraction remove it normally on long (6-10 Min.) exposures, was the Pix. taken as a RAW image, how was it converted to a TIFF (I assume it was), all in all a nice Picture of comet McNaught I wish we could see it, its been cloudy here since the 15th of last month so no chance.
vertical banding actually will happen in pretty much every digital camera under the sun if you push the sensor hard enough. Some are just less obvious than others
The vertical banding is rather obvious to me...But only if your looking for it.
Ah ok I see what you're talking about now.
Quote:
Originally Posted by fringe_dweller
no I dont mind at all, wow! nice work RB!
I am guessing here/ but you have run it through a noise reduction proggy and giving it a darkframe?
Yes I ran it through Neat Image N/R.
I don't usually like using N/R software because it gives the images a "Plastic" look, but now and then I might.
No dark frame though, only you can apply that at the time of imaging so it's taken at the same ambient temp by the same camera.
Quote:
Originally Posted by fringe_dweller
here is a cropped close up section of same pic, using jpg only and stretched and sharpened to bring it out hopefully (i did once think that it was a jpg issue, and tried a converted to 16bit TIFF of same pic, it definately reduces it (the banding), but its still there to a certain extent.)
the banding isnt full on obvious I guess, its bit faint, i should of said before, but its still there.
i appreciate you taking the time to help me out here Andrew! I wish it was all in my imagination
There's no advantage in converting from jpg to 16 bit Tiff because you can't add information/detail to it that's not already there. Shooting in jpg is not the best way to capture the maximum amount of detail, your best off shooting in RAW for most type of imaging.
I don't think there's too much to worry about Kearn.
Quote:
Originally Posted by sejanus
vertical banding actually will happen in pretty much every digital camera under the sun if you push the sensor hard enough. Some are just less obvious than others
I agree with you, I think it's normal under these extreme conditions to see this with most/any DSLR.
Here's a shot I took in 2004 using the old trusty 300D.
Notice the severe amp glow !
This has improved with the new models (350D, 20D, 400D, 5D) considerably.
I've pushed the levels to reveal some horizontal banding. Doesn't bother me as the images it produces are fine.
Thanks Asi, have you seen a similar thing in your 400D mate? Someone else sent me a private message with a pic from a 400d and the banding was present, altho not as bad as my 350D shows
Jim, no dark frame has been done, and it is from a maximum quality JPG - i had camera in jpg/RAW format when taking it, so I have both, as i mentioned its not as bad when using the CR2/RAW converted to 16 (12)bit tiff - but the banding stands out without doing any processing - which to me is unacceptable unfortunately - it gives me the heebee jeebies to be honest! wouldnt be too bad if i was photographing zebras at night
I have never taken an image longer than 30 sec with camera Jim, so cant answer that, sorry!
Sejanus, i had never noticed it before in either my Nikon CP 5700 or CP 4500 digicams prior, altho they are VERY noisy, much much more noisier and primitive chips, but its just random like i would expect, they dont exhibit the same pattern/banding thing at all.
I will be getting a 400D just the same 10 MP is very attractive anyway.
and for such a common feature/problem?, i have never seen anyone talk about here!?
hmmm confused is it the secret digital shame no one will talk about! hiding it from us film guys all these years
i am thinking it must vary from individual 350d camera to 350d camera, QC? - i had never noticed it in anyone else's images either - thats why i thought mine was an isolated case?
cheers RB, yes a little banding there - my 350d shows much more banding/pattern than that tho.
interesting comparison! man they have come a long way! re the amp glow! I had heard the 400d was even better again
sorry! i did mean to say converted from CR2/RAW to 16 (12) bit TIFF in that sentence earlier Andrew
I don't see anything like this either my 300D + 350D even in images that are 3-4 stops underexposed and then stretch back up to normal levels. Proper dark frame/flat fielding may take care of it. If its an electical interference problem FFT (Fast Fourier Transform) techniques will remove it, I know IRIS has that capability (I have use it once and twice and it works well).
ahh - thankyou very much Terry, i knew it wasnt right, if anybody saw the results i saw on my monitor, they would definately be saying the same thing as me.
thats heartening to know there is a possible cure even for the existing pics, using IRIS :-)))
cant see how there was any RF or electrical interference tho, i couldnt of been more free of interference some of the occasions i used the 350D in the country, at more than one location too - I mean my early shots I didnt even have the remote that i have now, just fingers, and they still show it, i use two different batteries, ...wonder if its the card? - could be a place to start, altho that was a top of the line card at the time of purchase.
Terry, can the electrical interference damage happen after the shots are taken? or only whilst your taking them?
anyway- now I know I definately want a new camera - i can move on, maybe canon may even help still - guess i should try perhaps
Hello Jim, I had a 350d for a while before it took a swim in the ocean
, the camera performed great on almost everything i targeted.
in the near future.
i have asked here before what it is, and recieved no answer at the time - i would dearly love to know if its 'normal' or in fact faulty - which is it? 
) 
is it the secret digital shame no one will talk about! hiding it from us film guys all these years 
