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Ventureoverland
14-10-2013, 1:53pm
Apologies if this should be in the Canon area. I put it here so as to get a general consensus.

My Camera - Canon 5D Mk III
My lens (for the purposes of this discussion) - 24-70 f2.8L

My question / Dilemma (bear with me) is this:

Ive long thought my 24-70 wasnt really wide enough for some landscapes and keep looking at the 16-35 MkII or 17-40, but not yet bought anything.

Ive also noticed that when shooting stars and the Milky Way that 24mm isnt normally wide enough either.

I know I could stitch for Landscapes but its a PITA / impossible when stacking startrails!

After reading a lot of threads, it strikes me many use about 10mm (on a cropped sensor) for night work and between 10mm & 22mm for landscapes (again cropped sensor), then last night I had a thought. What about using the 8-15mm Fisheye. I dont think this is as crazy as it may first seem. At 15mm on a full frame its VERY wide, only at 8mm is it circular and between 8 & 15 has varying degrees of circular-ness (is that even a word??)!

If 15mm on the full frame produces a decent image (albeit at f4), this could be used for landscapes and also for night work (may need to just lift the ISO up an extra notch to compensate for no f2.8). The missing bit obviously (compared to the 16-35) is the zoom from 15mm through to 24mm. The benefit though would be that I also have a fun lens for playing with (below 15mm).


Just had a thought... the 8-15mm wont accept filters because of its front curved element... Maybe the above is all rubbish because of this last nugget?

Any thoughts?

Thx
J

ameerat42
14-10-2013, 2:08pm
Well, the "width" of the (field of view of the) lens is mainly a matter of choice.
The main thing is to get as much light as possible onto the sensor, so a certain ACTUAL width of glass is helpful,
since stars are point sources of light. Landscapes are not point sources, and so any lens of suitable width would suffice.
Any "pretty-short-focal-length" lens, even working at full aperture, will give a pretty small exit pupil for the light, and maybe insufficient amounts of the latter for stars.
All this depends on the capability of your camera system. LOOOONG exposures may be required to allow a decent exposure, and
then also some tracking of the stars as they "move" across the sky.

As for the idea of a fisheye lens for stars, why not? The "circular-ness" is vignetting, and can be quite acceptable in pictures.

If filter attachment is a problem, try different exposures for your landscape (certainly not for stars) and then blend them.
Am.

PeaSoup: If it is not apparent, you are talking about two different photographic issues.

Ventureoverland
14-10-2013, 4:47pm
Thanks Am. Food for thought.

With regards Pea Soup, yes I am talking about 2 different issues / types of photography and wondering if the fish-eye would do both jobs ok and give me a fun lens at the same time, or wondering if I should stick with my initial thought of 16-35 / 17-40.

Thx
Jon

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ameerat42
14-10-2013, 7:50pm
Well, Jon. I'd say go ahead and see how it goes - if it's not too expensive.
Am.

Ventureoverland
15-10-2013, 7:06am
...If it's not too expensive...

Well isn't that a dilemma! What is too expensive!?!?! Its a cool $1k give or take for either lens, so neither exactly cheap!

Before jumping in with both feet I suspect I'll need to hire / beg / borrow them both for a choice weekend of shooting and see how I get on although at this point I'm concerned about the lack of LEE filter accommodation on the 8-15.

Just got to get moved into the new house first!

Thx
J

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Hayaku
16-10-2013, 3:56pm
Something to consider though. A 10mm on a canon crop should have a 16mm equivalent field of view.

Wouldn't the 16-35/17-40mm field of view be roughly the same then?

Also iirc Sigma has a 12-24 non fisheye for full frame. It might be just wide enough for what you're looking for.

Ventureoverland
16-10-2013, 5:42pm
Something to consider though. A 10mm on a canon crop should have a 16mm equivalent field of view.

Wouldn't the 16-35/17-40mm field of view be roughly the same then?


Yes, thats why I identified the 16-35 / 17-40 for my full frame.



Also iirc Sigma has a 12-24 non fisheye for full frame. It might be just wide enough for what you're looking for.

Thanks, I didnt know this was for full-frame. I'll look into it.

Link to the Sigma 12-24 DG is here for anyone else wanting it - http://www.sigmaphoto.com/product/12-24mm-f45-56-dg-hsm-ii

R
Jon