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18mp or 12mp canon eos?

maxheadroom

By maxheadroom
in Getting Started With Imaging

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maxheadroom

maxheadroom

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Morning campers!

I'm getting the urge to have a dabble in AP. Moon and planets first on my alt az mount with short exposures then maybe a wedge in the future.

With regards to AP is there an awful lot to be gained with the 18mp eos cameras over the 12mp cameras?

Will the entry 1100d be ok?

I'm not too fussed about daylight photography so it will be just for AP so I take it I need an astro modified camera without lenses? Do they attach direct to the body into the scope with a t ring so no camera lense?

Sorry for all of the mundane questions!

Max

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Langy

Langy

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Hello Max

I'm sure you will get a lot of answers on this one.

I think you will find the preferred method will be the body only with the T-Ring to attach to the scope. I found with my EOS 300D I have to use a 2xBarlows on my scope which is fine as I'm only doing Lunar mainly and that is great.

It will be interesting to hear the 12 - 18MP answers. In daytime photography I would say that it doesn't make any difference unless you are going to print posters or are bad at framing your subjects where you have to constantly cut small parts of the image for your subject. My camera is only 6MP and that for daytime should be more than sufficient for A4 prints. Now I'd like to hear how people class this for AP as it seems more about capturing the subject rather than the final size, where for me working in daytime it's all about how much you cam capture for enlarging etc. AP seems to be more about displaying on the screen not to put it on paper, well that's what I've made of it during my 1 month experience into Astronomy, so I'm hardly an advanced user to this hobby.

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maxheadroom

maxheadroom

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Cheers Langy. I'm sure I'll be advised to get a £5k mount and new full set up but in reality I just want a dabble mainly on the moon.

The 18mp seem I be about £100+ dearer but I wonder if it's worth it for this application?

I took a couple of moon shots with my iPhone so as long at they are sharper and more detailed it will be a step forward :)

Max

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jambouk

jambouk

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T-adaptor off ebay to clip into the eos connection of the camera body, then you need something like a T to 1.25" nose piece (or 2") to screw into that and slot into your focuser; £6 each off ebay.

Depends on your scope what you'll need between the camera and scope, as to how well framed your target will be. Look in the inaging-planetary section of the forum to see what planetary imaging people are doing with a dslr (most people would say don't bother with planetary with a dslr, but there are some impressive results there to see). Lunar will be easy, either single shots, ir stacked single shots, or stacked video (if the dslr has video mode); or a mosaic of any of those methods if you have a long focal length scope and can't fit the whole moon into the field of view with the dslr at prime focus.

DSO stuff, wait for the clever guys to comment, but even with an alt-az mount people havr got impressive results (again need to search the forum to find them).

I suspect for starting out, and with the limitations of an alt-az mount, i don't think you'll notice much difference between 12 and 18 megapixels per se, just maybe the more modern sensor may be more light sensitive (have better quantum efficiency) and it may also have fewer hot pixels and lower noise and permit higher ISO settings to be used without creating excessive noise.

I'll try and find some links when i boot my computer.

Jd

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rob0971

rob0971

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12mp is more than enough for daytime photography. I used to print A3 from 6mp without any problems. I am guessing that its also plenty for astro as well. Don't get caught up in the mp race. Its a ploy by manufacturers to get you to upgrade to the newer models. Processing will also be quicker with less mp & storage will take up less room. Also the denser the photo sites are packed on a chip, the more noise is generated, though newer models handle this a lot better than they used to. More important are features such as live view for astro.

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jambouk

jambouk

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T2 to EOS:

http://www.ebay.co.uk/itm/T2-Lens-to-CANON-EOS-Mount-Adapter-Ring-fits-EOS-7D-50D-60D-500D-550D-etc-/111256402377?pt=UK_Photography_CameraLenses_Lens_caps_hoods_adaptors_ET&hash=item19e765f9c9

T2 to 1.25" nose piece:

http://www.ebay.co.uk/itm/1-25-T-T2-Mount-Prime-Focus-Photography-nose-Adapter-for-Telescope-/200865914713

DSO imaging with alt-az mount:

http://stargazerslounge.com/topic/185409-imaging-with-the-skymax-127/?p=2093550

Jupiter with a DSLR:

http://stargazerslounge.com/topic/208001-jupiter-and-moons-c6-sct-canon-500d/?hl=%2Bjupiter+%2Bdslr#entry2214095

http://stargazerslounge.com/topic/206517-my-first-jupiter-dslr/?hl=jupiter+dslr#entry2194594

http://stargazerslounge.com/topic/202686-jupiter-111213-dslr/?hl=jupiter%20dslr

JD

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maxheadroom

maxheadroom

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I'll be using an F10 SCT. Far from ideal I know with 2034mm focal length.

I've seen some decent stuff from these scopes and I definitely don't want to get caught up in massive expenditure (I suppose everyone says this!) but equally I don't want to make the wrong initial purchase that needs to be changed when I pick up a little bit of knowledge

:-S

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Alien 13

Alien 13

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Cheers Langy. I'm sure I'll be advised to get a £5k mount and new full set up but in reality I just want a dabble mainly on the moon.

The 18mp seem I be about £100+ dearer but I wonder if it's worth it for this application?

I took a couple of moon shots with my iPhone so as long at they are sharper and more detailed it will be a step forward :)

Max

Hi Max im one of the few who wouldnt recomend an expensive mount as a minimum you can get decent results with a lesser mount its just a bit more limited regarding weight and FL of the scope etc.

The issue regarding 12 vs 18 megapixel i dont know if its relevent or not as Jd said the newer sensor might be a more important factor but i chose my 18mp mainly for video recording and general photography it does however work fine for AP.

Alan

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jambouk

jambouk

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Removing filters from the Canon will not be necessary for planetary or lunar imaging.

It will help with DSO imaging if the object emits hydrogen alpha, though the factory fitted filter probably allows 30% of hydrogen alpha through anyway.

I would just check if making this modification was worth while if you are limited to 20 second exposures anyway with the alt-az mount, and limited to certain DSOs (some of which may not emit shed-loads of hydrogen alpha anyway) - I know very little about DSOs.

JD

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maxheadroom

maxheadroom

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Thanks JD! Top man!!!!

Sorry I'm on a small phone at the moment so struggle navigating quickly.

Max

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jambouk

jambouk

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Thanks JD! Top man!!!!

Sorry I'm on a small phone at the moment so struggle navigating quickly.

Max

I was too, but your thread encouraged me to get out of bed and boot the PC - the plumber is coming anyway to look at moving some pipes in my garage to make way for an astro-door through the wall :)

JD

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maxheadroom

maxheadroom

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I was too, but your thread encouraged me to get out of bed and boot the PC - the plumber is coming anyway to look at moving some pipes in my garage to make way for an astro-door through the wall :)

JD

Haha quality! An astro door? Will it be sort of like a blast door off starwars and make a wooshing sound? That would be sweet B-)

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jambouk

jambouk

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Haha quality! An astro door? Will it be sort of like a blast door off starwars and make a wooshing sound? That would be sweet B-)

No, just a bog standard door from my garage into a lean to shed outside so I can get access to my garden without tramping through the house. Though the whooshing sound is appealing :)

JD

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jambouk

jambouk

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Max,

I've got a 600D with the flip out screen; it is so handy to have that screen when the camera is mounted to the telescope and the scope is pointing higher than 45 degrees elevation; when it's looking at the zenith it's an absolute nightmare to try and see the LCD display.

So, if not getting a camera with a flip out screen, make sure you get one which can be operated easily from a laptop in the field.

Check out the Canon 60Da (online and reviews on here).

JD

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maxheadroom

maxheadroom

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Max,

I've got a 600D with the flip out screen; it is so handy to have that screen when the camera is mounted to the telescope and the scope is pointing higher than 45 degrees elevation; when it's looking at the zenith it's an absolute nightmare to try and see the LCD display.

So, if not getting a camera with a flip out screen, make sure you get one which can be operated easily from a laptop in the field.

Check out the Canon 60Da (online and reviews on here).

JD

Cheers James, I wouldn't have thought of that!

Thanks for the tip

Max

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ollypenrice

ollypenrice

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The trick in AP is to match focal length to pixel size, a value called 'arcseconds per pixel.'

The ideal for your FL would pixels larger than any found in DSLRs so I would consider the higher count model a disadvantage. (Essentailly, for most telescopes DSLR pixels are too small already and are getting ever smaller, which is a shame.)

The problem in AP is signal to noise. We have very little signal but quite a bit of noise, so larger pixels get a bigger share of the incoming signal than small ones and the S/N ratio improves.

Olly

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Alien 13

Alien 13

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The trick in AP is to match focal length to pixel size, a value called 'arcseconds per pixel.'

The ideal for your FL would pixels larger than any found in DSLRs so I would consider the higher count model a disadvantage. (Essentailly, for most telescopes DSLR pixels are too small already and are getting ever smaller, which is a shame.)

The problem in AP is signal to noise. We have very little signal but quite a bit of noise, so larger pixels get a bigger share of the incoming signal than small ones and the S/N ratio improves.

Olly

Oh dear im sunk then with a 18mp camera and a scope with a FL of 335mm still im happy enough with my results.

A serious question though Olly does there come a point when the pixel size value in fact covers 4 pixels in a matrix?

Alan

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lensman57

lensman57

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Morning campers!

I'm getting the urge to have a dabble in AP. Moon and planets first on my alt az mount with short exposures then maybe a wedge in the future.

With regards to AP is there an awful lot to be gained with the 18mp eos cameras over the 12mp cameras?

Will the entry 1100d be ok?

I'm not too fussed about daylight photography so it will be just for AP so I take it I need an astro modified camera without lenses? Do they attach direct to the body into the scope with a t ring so no camera lense?

Sorry for all of the mundane questions!

Max

Hi max,

Please don't get hung up on Mega Pixel count. This hype is only applicable to terrestrial photography and fortunately not AP. A modded canon 1000d or 1100d are  more than adequate. I always draw comparison to the Cooled CCDs and of  two of the best around one is 1.3 megapixel and the other 2.9 and these cost from £1200.00 and £1500.00 for the basic kit. No mega pixel  race here I am afraid. An 1100d is an excellent camera even for advance users, the trick is in the processing of the data files and here the quality of the data rules not the quantity.

Regards,

A.G

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