Canon Lens's

[TobyW]

Hi All,

 

I wonder if I could get some billy basic advice on camera lenses. I have 2 that I use with my DSLR (see pics) that I have had in my possession for a very long time. I am struggling to get anything in the way of decent pics of star clusters, galaxies etc. I suspect that the lenses aren't that great. Could someone please give me some beginner level advice on the sort of lens I would need to get pics of say the crab nebula or Andromeda etc..

 

Cheers

Toby

[jgs001]

Toby, you should be able to manage passable images, but, without tracking it'll be difficult (18mm on the kit lens), and you may well have to stop the lenses down quite hard, which will then require longer exposures. One thing I have discovered, Macro lenses are superb for astro imaging, as you can use them wide open. What are you putting the camera on?

[Stardust]

Zoom lenses tend not to be that great for our purpose. You'd be better off with a prime lens. to give you an idea this shot was with an old M42 Zeiss 135mm f3.5 lens on a tracker mount and stacking frames. A Tamron 90mm macro f2.5 the older is a very flat field lens. You don't need autofocus and i'm sure there'll be a lot more lens recomendations..

 

 

[TobyW]

2 minutes ago, jgs001 said:

Toby, you should be able to manage passable images, but, without tracking it'll be difficult (18mm on the kit lens), and you may well have to stop the lenses down quite hard, which will then require longer exposures. One thing I have discovered, Macro lenses are superb for astro imaging, as you can use them wide open. What are you putting the camera on?

Hi John,

 

Thanks for the reply.

 

OK, so this is where the newbie part in me shines through

 

1) What do you mean "stop the lenses down quite hard"

2) I have heard the term "use them wide open" a few times. Again, sorry for my ignorance, what does that actually mean. Is it when you have it fully zoomed out? In other words the aperture of the lens is at it's widest it'll go?

 

I don't actually have a tracking mount at the moment but talking to a chap on here about a Star Adventurer so tracking is coming. At the moment I found found that if i use long exposures I get the classic star trails. I am usually taking my pics at around 400 ISO. 

 

how do you get these long distance objects like galaxies (you cant see them with the naked eye) into focus?

 

Cheers for all your advice.

Toby

[TobyW]

1 minute ago, Stardust said:

Zoom lenses tend not to be that great for our purpose. You'd be better off with a prime lens. to give you an idea this shot was with an old M42 Zeiss 135mm f3.5 lens on a tracker mount and stacking frames. A Tamron 90mm macro f2.5 the older is a very flat field lens. You don't need autofocus and i'm sure there'll be a lot more lens recomendations..

 

 

WOW, that looks amazing. if I can get to that sort of pic I would be a happy chap...

[Stardust]

Don't try this till you have a tracker, shorter focal lengths are more forgiving on tracking. A Pentax  M135 f3.5 is pretty good and very cheap. you can then get a pentax to canon adaptor.  

[happy-kat]

M31 is one such target you could image with a static mount but you would need a good 400 images.

Here is a video https://youtu.be/e0JSTF8SGi4

[Erling G-P]

"Stopping down" & "wide open" both refers to the aperture settings of lenses.  Wide open means using the largest or near largest opening (= small aperture number). Stopped down means smaller openings (= higher aperture numbers)

The lens will let in the most light at the largest openings of course, but most, if not all, will produce a sharper image if you use a smaller aperture opening, and the depth of field also increases, making focus not quite as critical, but at the cost of letting less light through.  The more wide angel the lens, the less pronounced the depth of field effect is though, so keep that in mind - it matters most for longer focal lengths.

[jgs001]

Something else to bear in mind.. the infinity focus mark on the lens... on you're lenses (at least the 18-55) the focus ring will move past it (the stop is not at infinity but beyond it (weird as that sounds), apparently to allow for temperature fluctuations, so something else to bear in mind when focusing. If you have a recent canon (with liveview) and an android device with a USB OTG port, you can use the DLSR controller app to set focus.

Take a look at

and give it a try. This will not produce the best images, but it will get you going, and get you some experience of using the gear and image processing.

[PeterCPC]

To nail focus just use Live View and point at a brightish star then turn the focus ring until the star is as small as possible.

Peter

[TobyW]

41 minutes ago, jgs001 said:

Something else to bear in mind.. the infinity focus mark on the lens... on you're lenses (at least the 18-55) the focus ring will move past it (the stop is not at infinity but beyond it (weird as that sounds), apparently to allow for temperature fluctuations, so something else to bear in mind when focusing. If you have a recent canon (with liveview) and an android device with a USB OTG port, you can use the DLSR controller app to set focus.

Take a look at

and give it a try. This will not produce the best images, but it will get you going, and get you some experience of using the gear and image processing.

Hi,

 

useful info that. thank you.

 

Where is the infinity focus mark? I know that probably sounds daft but there are no markings on the lens (18-55mm one) that I can see. There are the marks for how much youre zoomed in or out?

 

Cheers

[happy-kat]

Infinity is like a squished 8 laying on its side and is on the right side of the lens focus distance markers where available.

[TobyW]

Hi,

 

There is no ininity mark on either of my lenses... Shame

 

Toby

[jgs001]

Toby, I suspect they didn't include one, as to do so, and then allow you to move the focus ring past it would be rather odd. To rephrase, the focus ring will turn past the infinity focus point, which is apparently to allow for temperature variations. So don't rely on the end of the focus ring travel as being infinity focus.

[TobyW]

6 minutes ago, jgs001 said:

Toby, I suspect they didn't include one, as to do so, and then allow you to move the focus ring past it would be rather odd. To rephrase, the focus ring will turn past the infinity focus point, which is apparently to allow for temperature variations. So don't rely on the end of the focus ring travel as being infinity focus.

Ahhh right now I got you. Or at least it makes a little more sense

 

Thanks John

Toby

[MattGP]

I’ve just started with pretty much the same lenses as you (my bigger is 300mm) and have the Star Adventurer too

I’ve captured Orion Nebula so far, but not sure if light pollution will let me capture any galaxies - that said it’s still great fun taking zoomed pictures of what I can and the 18mm lens for wide sky star shots.

also go on to canon website and download the canon photo editing software, it’s actually quite cool- these are some pics I’ve taken with my lenses 

[FaDG]

Hi Toby, sorry to be blunt but the 18-55 II is not very well suited for the astro use. 

I've had one sample, it was the kit lens of the 350d and 400d Canon: its sharpness leaves a lot to be desired and manual focus (you can't rely on autofocusing) with the small front Ring is pretty lame. 

Furthermore, at 55mm it's f5.6 wide open, and even consistently stopped down (let's say f8) it still does not satisfy. 

The following kit lenses 18-55 IS (image stabiliser) versions are much better, although not the top for astro. 

Edited April 8, 2020 by FaDG

[TobyW]

Hi,

Blunt is fine with so no worries. I didnt think the lenses I had were any good (for astrowork) hence me asking the question.

 

Cheers 

Toby

[happy-kat]

Anything you take with the lens you have is more than you would otherwise take. They're is much to learn and starting with what you have already to hand is not time wasted as many skills can be taken forward. There are lots of astro programs which many use and are no cost. To name a few.

Deep sky stacker

Starstax

GIMP

Sequator

Registax

The kit lens isn't bad, if wide or near wide open then f5 is generally fine.

[happy-kat]

A quick search found this post with a kit lens image

Link here

[Alien 13]

I had the 18-55mm IS lens and it was fine, a pain to focus with its sloppy focus ring but provided you picked a feint star away from the center to get focus then it could be used wide open, it performed far better than my nifty fity which still struggled even when set at f/8.

Alan

[happy-kat]

Also I've found focus much easier to sustain when using back button focus (search on how to set that up) on your canon.

[FaDG]

35 minutes ago, happy-kat said:

A quick search found this post with a kit lens image

Link here

Alas, if that image was shot with the 600d kit lens, then it's the later version of the 18-55, the stabilised one. 

I've had both and the difference is striking: i obtained this decent milky way with the new one (18-55 IS) . I agree with you that whichever lens is better than no lens at all, but knowing the limits of one's equipment can reduce the frustration. 

Edited April 8, 2020 by FaDG

[happy-kat]

Looking at the first image made by the OP the picture of the kit lens clearly shows it is II which to me is the second edition and that has image stabilisation, which if reading the post earlier suggests it is the more recent flavour of the lens and is sharper. 

[maw lod qan]

Welcome to the forum.

What Canon are you using. I have a SL1 and use the 18mm 55mm. Without a tracking mount you will be limited on what you can image, but that doesn't mean you still cant have lots of fun.

I've used mine a lot doing widefield for meteors with an interval timer to shoot  images all night.

I also use mine with an 8" reflector telescope.