Lenses for astro/nightscape photography.

autofocus

@spraynpray, best I can do with the trees in my yard. Hope this helps. Full res on Flickr. 2.8, iso 3200, 2 sec exp. WB K4000.

spraynpray

Thanks Chuck, that image shows little aberrations even at 1:1 (and that is about 6 feet wide). I like that lens, it would be fun to own one. I've never even wanted a fisheye before, so is it possible to correct the distortion back to normal?

autofocus

Andrew, here is Matthew Saville's review of the lens and how to correct the Fisheye distortion.


Here is a quick tutorial on using Fisheye Hemi. A program to de-fisheye photos.


I recommend watching both. They will give you more insight on the lens and post-processing to make a learned decision.

Msmoto

I wonder why one could not just rotate the image 90º and the program would straighten the "vertical" horizon...? Or, just keep the camera back vertical...of course this does lose a lot of sky....

Maybe I need to try this.....tonight if the rain stops....LOL

autofocus

I just tried the Fisheye Hemi (Trial Version) and think I might have to watch the tutorial again. I didn't have the same results as the instructor...haha

autofocus

Rokinon 12mm, 3 photos. Actually the same photo 3 ways.

No distortion correction:


Five minutes in PS using the Warp Filter:


One pass with Fisheye Hemi:

Ironheart

Thanks Chuck, that image shows little aberrations even at 1:1 (and that is about 6 feet wide).

Err.. Are we looking at the same image? I count a lot of birdies 'specially in the upper left.

spraynpray

@autofocus: Interesting, thanks.

@Ironheart: Sure there are some, there always are some, but look at the size of the file and the size of the print for the size of those aberrations. MUCH better than any Nikon lens I tried. At 3' x 2' you would struggle to see them.

Nikoniser

Looks like it s Zeiss to the rescue .... maybe a less ambitious 28mm and Zeiss knowhow will make the ultimate astro landscape lens, but at what price ?

http://lenspire.zeiss.com/en/zeiss-otus-1-428-world-class-wide-angle/

Nikoniser

Starfield full size https://www.flickr.com/photos/carlzeisslenses/21512460523/sizes/o/

Looks pretty good !

kenadams

Nikoniser, speaking of Zeiss, there's also the Milvus 21mm 2.8 for 1/3rd of the Otus, plus more fov.

CirenSnapper

.....and now the Sigma!

Nikoniser

Nikoniser, speaking of Zeiss, there's also the Milvus 21mm 2.8 for 1/3rd of the Otus, plus more fov.

If I wanted an f2.8 lens I would get the 14-24 Nikon, it has great coma performance.

But an f2.8 lens lets in 4 times less light than a 1.4 lens, however all the 1.4 lenses need stopping down to at *least* f2 before performance becomes acceptable.

So an F1.4 lens that is sharp wide open is with decent coma performance and minimal vignetting is big news.

kenadams

4 times *less* light, holy cow Batman!!

I was merely making a suggestion based on the price tag and FOV of the Otus (or rather the Milvus). But you seem to have the 4 grand handy, so nevermind ;-)

spraynpray

I've seen Zeiss nightscapes that are way inferior to the 24/1.4 Samyang. Also I have learned the hard way that what people say about coma is cr@p. They sometimes may even be 'OK' for coma, but the sagittal and tangential astigmatism makes them unusable (for me). All major makes included in that last statement.

heartyfisher

new sigma 20mm 1.4 rumoured ...

Ironheart

The milvus is less appealing for astro, as it is much less corrected, I don't think it is apochromatic, and it's a 2.8. Great lens otherwise.

Ironheart

new sigma 20mm 1.4 rumoured ...

From the main blog:

http://nikonrumors.com/2015/10/14/new-sigma-20mm-f1-4-dg-hsm-art-lens-to-be-announced-this-friday.aspx/

One of the "features":
Designed to minimise coma aberrations

I can't wait to see!

spraynpray

Nikon said 'coma minimised' on the 20 too, but that turned out to have bad astigmatism.

Also, regarding the Sigmas, night shots mean manual focus and the 90 degree focus travel of the Siggies makes the stars very hard to get sharp (and I use a 10x loop on the rear screen).

spraynpray

Well, my night sky lens of the moment is the 24-35 Sigma. Aberrations are good, focusing is easier than the Samyang 24/f1.4 plus you have a super sharp zoom with AF for landscape.

One thing a little off piste: Is it me or is the D750 a complete swine to try to focus in black conditions? The random colour noise that plagues the live-view screen is absolutely wretched. Is it mine or do others have the same problem with it? My mates 6D and 7D2 are far easier to focus.

heartyfisher

I have not heard of lenses exhibiting astigmatism .. what does it look like? I have had a google about and found this.. and I still don't know what to look for .. can you shed some light .. (yeah I am in the mood for puns LOL Must be the lack of sleep ) .. http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/coma.html

spraynpray

Tangential and sagittal Astigmatism are explained here:

http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/coma.html

Coma makes dots look like flames, while the astigs make flying doves in the corners and even near the edges if it is bad enough. Whatever, they are just aberrations to me and they ruin night sky shots.

What about the terrible noise in live view Hearty?

heartyfisher

Re LV noise.. dunno.. dont have the D750.. first I have heard of this .. not that it couldn't be right.. maybe not many astro photographers use D750..

framer

Has anyone used a 15mm AIS f/3.5?

or the 28mm AIS f/2 or f/2.8?

framer

WestEndFoto

Both (not the 28 2.0). But I never thought of using them for astro since I have the 14-24 2.8.