dslr vs compact?

[chemtom24]

hi guys,

just wondering if someone could explain to me the major differences between the two types of digital camera - been looking on ebay and dslr's are alot more expensive than a compact, but compacts seem to have higher megapixel (and therefore resolution??) than the dslr's.

so since in a couple of weeks time when my student loan comes through im going to buy a camera, ~150+ to spend, with astrophotography in mind, what should i go for? i want to have some exposure control, tho i am also going to have a uni mate LX mod my neximage for me. i just dnt know where to start with this.

astromaster 130 eq, neximage

[brianb]

Compacts have tiny sensors which means low sensitivity / high noise. Don't be fooled by the figures ... compare an ISO 400 image made with a compact (horribly noisy) with an ISO 1600 image made with a DSLR (can be fairly smooth). And 6 MP is plenty unless you want to print bigger than A4; in fact 1 MP is more than enough for images to post here.

DSLRs also have interchangeable lenses and a decent optical viewfinder. Very useful not having to work afocally for astro work. Build quality is usually better, even for the cheap models at the bottom end of the market.

Really there's no competition - DSLR wins by a huge margin. If you're short of money get a second hand one, or a new one of an obsolete model, these often turn out pretty cheap.

[chemtom24]

thanks for reply, some good advice to which i will heed. I could maybe push to 200, do you know of any reasonable cameras i could get with that, makes n models? i really have no idea. o shold really be concentrating on revision for exams but this is more exciting!

[MikeWilson]

A used Canon 1000D body could be gotten for that maybe - plus £80 or so for a "nifty fifty" f1.8 and you'll be away!

[chemtom24]

A used Canon 1000D body could be gotten for that maybe - plus £80 or so for a "nifty fifty" f1.8 and you'll be away!

maybe somehting just a little cheaper, so in total 250 max? also, i keep seeing this 'nifty fifty' term lol, what does it mean? and with a dslr, i will be able to attach it to the telescope yea, without eyepieces?

[MikeWilson]

Nifty Fifty: Flickr: Canon EF 50mm f1.8

DSLR's can attach to telescopes, but it depends on the DSLR, the telescope focuser and the adapter.

I have a 1000D which uses an EOS to T-thread adaptor and then a Baader MPCC which screws into the T-thread and then gives a 2" end to drop into the focuser. If you don't have a MPCC you can use a simple metal adapter.

Clear skies,

Mike

[chemtom24]

is the no-live preview a major issue?

[chemtom24]

also, i keep seeing 'body-only' what does that mean? i can just buy the camera with accesories?????

[pook]

That just means no lens.. just the body. If you only plan on using it for astro work, that's what you want. If you want it for general use, you need a lens as well.

Remember though, that unless you choose a SLR with a full size chip (same size as 35mm film) the 50mm lens will have an effective focal length of 85mm or so.

The "50" is touted as the first ideal lens because it's fast, and offers a natural field of view similar to the eye. However, unless you have a full size chip, a 35mm lens is actually the "standard" focal length.

Lack of live view is an inconvenience certainly, but not essential.

[malc-c]

I've just paid £239 for a used Canon 400D that came with an 18mm - 55mm lens, two batteries, USB cable, mains charger and strap, all boxed and in excellent condition from a local photographic shop. Just need to shop around.

[pook]

That was a good buy! Well done!

[ollypenrice]

The Canons are the best supported for astonomy. If you need to wait a little to get one then that's what I'd do because compacts have no astronomical application other than lunar snaps.

Olly

[brantuk]

Pop in the imaging section and check the signatures - you'll see that a lot of imagers use Canon's. Have a look at the Astronomiser website to familiarise yourself with Canons, as different models have different benfits. You can get s/h bargains from £150(ish) for a used 300D. 350D was the standard for many years, and recently the 1000D is a cost effective solution with live view for around £270(ish) brand new.

[Psychobilly]

Prices have risen quite sharply.. I was looking for another 1000D a few weeks ago and body only price is now a lot higher than i paid for the camera with the 18-55 IS lens when it first came out..

I'll probably wait and see how the 1100D pans out... still not stupid MP wise but 14 bit raws and movie mode...

Billy...

[russ]

You can certainly get something within budget. Even if your budget had been a lot lower it's still possible to get started with a DSLR. It's possible to start of with a 300D for well under £100 all in (including the 18-55 lens).

[E621Keith]

Buy used. Despite their age, astrophotos from 'ancient' DSLRs such as the 10D and 300D still looks incredible. With the right lens, they will still out class top end modern compact and bridge camera by a considerable margin for terrestrial and astro use. Resolution doesn't really matter when most compact's lens cannot support their multi mega pixel sensor's resolution. Making a high resolution sensor is easy, making a high resolution lens is not.

I don't know about the Canon 18-55mm lens, but I would rather spend money on a fast 35 or 50mm lens if your main goal is for astro. My Nikon 18-55 mk1's focuser tube will collapse under its own weight when pointed up, making it completely useless for long exposure wide field photography.

[Photohound]

i'd recommend canon dslr as previous guys have said... a quick scout on fleabay shows 300D's for buyitnow £109 and 350D's for buyitnow £140, so i'm sure there are some 'auction' bargains if you dig deep enough, and have the patience to hunt out a good one. Good luck.

[dph1nm]

Compacts have tiny sensors which means low sensitivity / high noise. Don't be fooled by the figures ... compare an ISO 400 image made with a compact (horribly noisy) with an ISO 1600 image made with a DSLR (can be fairly smooth).

The reason compacts are noisy is nothing to do with the sensor size, it is because they have small lens apertures (tiny in fact - maybe only a few mm) and so don't let in much light. hence the shot noise is high. If you are doing afocal astrophotography then this problem goes away (depends somewhat on the exit pupil size of the eyepiece actually) because you are using the telescope as the light collector not the camera lens. They also have the gain set much higher than DSLRs, to compensate for the lack of photons, which can make the noise seem much higher at a given ISO setting.

Some compact cameras actually have better read noise that DSLRs (they have to, given the lack of photons).

They do have problems (for astrophotography) of course - mounting then isn't easy unless they have a threaded lens (rare), you lose light through the extra glass in the eyepiece/camera lens (which also introduces astrometric distortions), and matching the eyepiece and camera to avoid vignetting can be a black art. Then if you want to do DSOs you have to find one which allows reasonable length of time exposure. It is possible though, but hard work.

NigelM

[Ad Astra]

Another thumbs up for Canon. I started out with an A70 compact Canon and moved up from there to a DSLR model. FAR superior!

Used Canon Rebel 300 should be excellent for you!

Dan

[pook]

Although I'm a hard core Nikon user for everything else, I'm starting to feel the lack of support for Nikon so far as Astronomy goes. I'm on the look out for a used 500D body just for astro work.

I agree with the others. Canon is the weapon of choice.

[brianb]

The reason compacts are noisy is nothing to do with the sensor size, it is because they have small lens apertures (tiny in fact - maybe only a few mm) and so don't let in much light. hence the shot noise is high.

Linear aperture is linked to sensor size by the angle of view of the lens.

Some compact cameras actually have better read noise that DSLRs (they have to, given the lack of photons).

The processing can make it appear that way, but the apparent "lower" noise is accompanied by much less detail in the image. You can't have low noise and high resolution without capturing more photons ... the tiny pixel sensors of the small super high density sensors used in compacts is a big downer for image quality.

[RikM]

Second hand 300D/350D or save up for a 1000D. I found the live view a definite plus for focussing.

[chemtom24]

i gotta say im not looking forward to having to take a snap, then look at it to see if it is focussed, then repeat until its right. thats gonna take some mighty good polar aligning skills on my behalf lol. also i imagine this makes it a hell of a lot harder to actually get your object in view?

but i have been made an offer from someone here, 230 quid for a used 400D with an 18-55 2 batteries n cables n whatnot. so im'a have that in a couple of weeks time when i get money through

[dmahon]

Before you buy a DSLR for your 130mm Newtonian, make sure that it supports prime focus photography. Some just don't have enough "in-focus".

[chemtom24]

Before you buy a DSLR for your 130mm Newtonian, make sure that it supports prime focus photography. Some just don't have enough "in-focus".

thanks for the heads up

unfortunately, it seems i will be unable to do it. B****R

I am still keen on owning a dslr tho, because i would like a decent camera to keep for a few years for normal photographs as well.

hmmmmm. very frustrated atm