Lenses for astro/nightscape photography.

spraynpray

Does anybody have any experience or information about lenses that are good for this purpose? The problem is sites like DxO don't test for coma so I thought I would ask the collective. The lens I am looking for has to be 1.4 or 1.8 and be usable at that aperture as light down the lens is king. Focal length must be from 14 to 24mm.

I have bought the Samyang 14mm f2.8 and the 24mm f1.4 because they were recommended as 'no coma' whereas in fact they were 'low' coma. @Ironheart kindly took a shot with his new 20 f1.8 which was better for coma than either of the Samyangs, but still has a little - it is most likely to be the lens I purchase so far.

This is an unusual situation in that when one asks for quality people always say 'Zeiss' but I have found Zeiss to be only average in this regard. Please don't take excellent IQ in any other regard as an indication of merit for coma, it isn't so. The easiest test is a shot of the stars wide open and then check the corners for flying doves.

I have read that the 14-24 is good but the problem is only f2.8 max aperture. The person recommending it is a blogger who uses a really basic workflow and only does small images on-line so has little credibility. Does anybody here know how it does for coma specifically?

Thanks.

tektrader

I suspect it isn't that good. I do get a quite a bit of edge smearing in normal use. BUT I have always been a bit suspect of the performance of my copy.

I will try to shoot off a frame of the milky way tonight for you and we shall see.

Ironheart

I recommend these two articles:
http://www.lonelyspeck.com/lenses-for-milky-way-photography/
http://www.lonelyspeck.com/best-lenses-for-milky-way-photography-nikon/

HipShot

I will try to shoot off a frame of the milky way tonight for you and we shall see.

So envious that you live somewhere you can do that.

heartyfisher

The new Tamron 15-30 looks nice .. for coma ( and other things :-) )

sevencrossing

I dont know about Astrophotography but in all other respects the AF-S NIKKOR 20mm f/1.8G ED is a fab lens
Is there any way I can test for coma for you without getting up the the night




take a few moments ago

spraynpray

I recommend these two articles:
http://www.lonelyspeck.com/lenses-for-milky-way-photography/
http://www.lonelyspeck.com/best-lenses-for-milky-way-photography-nikon/

Thanks Ironheart, but those are like 'night sky 101' in that the techniques are OK for popping an image on the internet at low res, but you just cannot do anything like that for large prints.

The new Tamron 15-30 looks nice .. for coma ( and other things :-) )

Thanks for the idea. Where did you see somewhere that even tests for coma?

I dont know about Astrophotography but in all other respects the AF-S NIKKOR 20mm f/1.8G ED is a fab lens
Is there any way I can test for coma for you without getting up the the night?

It only has to be pretty dark, for a rough test, not late. I am not looking at anything except the stars in the corners of the frame at the moment.

spraynpray

Hey guys, what about the Sigma 24mm ART? Anybody got one? DxO hasn't tested it on a Nikon yet so I can't assess it's other qualities there. Anybody know a test site that tests for coma?

sevencrossing

I live on the edge of Bristol is light pollution going to be an issue?

kenadams

Spraynpray, I was about to get the Sigma 24 and in the process of checking reviews, I think I remember findingg a site that suggested the 24 is better than Nikon's 24 1.4 with regards to coma, but far from being coma free. To me it seems the N20 1.8 is the better choice in that department.

What exactly makes you say the websites Ironheart mentioned are 101 but not suitable for large prints? I'm trying to read up on the astro/nightscape photography as I'll be moving to a place that seems made for that, very low light pollution and generally pretty deserted :-D

spraynpray

I live on the edge of Bristol is light pollution going to be an issue?

No Seven, it isn't. Shoot where you see the most stars and it will be fine. Anything is better than nothing thanks. Give it about 8 seconds ISO 3200 f1.8 and that should be enough. If it's too bright, go to lower ISO, too dark, go higher ISO.

@kenadams: It would be good if you could find and post a link to that site? As for night shots this isn't really the thread for going into that subject, you can PM me and I'll go into it a little more.

kenadams

Sp'n'p, that must have been it:

http://www.lenstip.com/430.1-Lens_review-Sigma_A_24_mm_f_1.4_DG_HSM_Introduction.html

Under 7.), the article goes a bit more in-depth with regards to coma

I guess you need to decide for yourself whether testing methodology is up to par, I can't judge that.

This one from lens rentals was also interesting (although only marginally about coma):
http://www.lensrentals.com/blog/2015/04/just-the-lenses-sigma-24-f1-4-art-comparison

These two represent the more critical articles I've seen. All in all, general consensus seems to be that the Sigma is on one level with its (way, way, more expensive) camera manufacturers' counterparts (be that Canon or Nikon), but nevertheless it is regarded the least mind blowing in the Art lens series or primes.

I'm seriously torn between the Sigma 24 and the Nikon 20 1.8; unfortunately, they're pretty close when it comes to price.

For what it's worth, I'd like to replace my aging 17-35 2.8, that I mostly use at 20-24 anyway.

spraynpray

Thanks Ken, That test rules out the Sigma 24/1.4, but then they also said the Nikon was equally pathetic in comparison to the Samyang. My experience is limited so far to the one image that @Ironheart posted which is better than my experience with the Samyang (Bower) so it looks like I will try a Nikon 20/1.8 from a shop with a good returns policy (WEX) problem is, they are out of stock at the moment.

kenadams

This here is also something that might be considered. This may not surprise the Rokinon/Bower/Samyang crowd, but check it out:
http://gwegner.de/review/sigma-24-f1-4-art-test-review/

Article is in german; the guy praises the Sigma and likes it very much; google translate to the rescue. Most important though, have a look at the wide open shots of the Hamburg Speicherstadt (that one storage house in the canal) and how the highlights even to the center of the frame compare between the Samyang and the Sigma.

I'm figuring since astro needs to be wide open and all.. this might be of relevance.

spraynpray

That test does seem to be saying that the Siggy has it's problems but is great used for genres with decent light. The superior contrast and sharpness of the Sigma over the Samyang is plain to see.

OK, I just had another look at @Ironhearts shot on Flickr:

https://www.flickr.com/photos/88560389@N06/19685014986/sizes/o/

Check the corners in some detail and then realise that when viewed full size on flickr you are viewing it at about 6 feet wide by 4 feet high, so it is extremely good. I want to get 24 x 16 shots without the problem showing at all and it looks like it is going to be able to do that.

I did look briefly at the 35mm siggy as that has virtually no coma at all, but when used for a nightscape with a subject in the foreground, the field of view is just too narrow to get enough sky in behind it. Shame, because it would have been useful in many other applications.

Any other ideas guys?

sevencrossing

Looks like I have a lot to learn
Too much moon light
Too much light pollution
quite a lot of seeing
not sure if my tripod is really steady
or if I have focussed correctly
anyhow. hear is a RAW file from tonight

https://dl.dropboxusercontent.com/u/15913272/DSC_3522.NEF

spraynpray

Thanks @sevencrossing. Don't beat yourself up about the conditions, there is plenty enough detail there to see the coma. Now it seems your particular lens has worse coma than @Ironheart's copy does. It doesn't mean a thing to you if you don't want to shoot the stars then blow your shots up, but it means to me that there is variability in this area of the 20mm f1.8 which almost certainly means (when you take into consideration sod's law) that I will NOT get a good copy. I will have to get mine from a company with a good returns policy as I may get through a few.

:-(

WestEndFoto

I wonder if there is software available that could turn star trails into points. That could permit longer exposures, rendering all this a mute point to all but the purist of purists.

heartyfisher

I saw the 15-30 tamron test at Lenstip ...

sevencrossing

I wonder if there is software available that could turn star trails into points. That could permit longer exposures, rendering all this a mute point to all but the purist of purists.

I am struggling to understand why a bit of coma is such a big issue
looking at my own humble attempts. "seeing" ( atmospheric disturbance) seems to be the biggest problem
The end result seems to be for artistic reasons, most people will know a star is a single point . no more information will be revealed by the lack of coma

heartyfisher

I wonder if there is software available that could turn star trails into points. That could permit longer exposures, rendering all this a mute point to all but the purist of purists.

There is .. its called an astro tracker :-) That is partly the reason why many astro photo enthusiasts go for the Pentax cameras that have it built into their sensor shake technology. Pentax also seems to have tweaked their sensors at High ISO for long exposure noise. Of course there are limits for sensor tracking but its heaps better than not having it and there are ways to merge multiple photos for hour long exposures .. however as pointed out in a previous Astro tread here .. getting an external tripod mounted tracker is not all that expensive nowadays...

sevencrossing

There is .. its called an astro tracker :-)

I think S&P wants to do "nightscape photography"
eg he also wants the landscape sharp

spraynpray

I wonder if there is software available that could turn star trails into points. That could permit longer exposures, rendering all this a mute point to all but the purist of purists.

I am struggling to understand why a bit of coma is such a big issue
looking at my own humble attempts. "seeing" ( atmospheric disturbance) seems to be the biggest problem
The end result seems to be for artistic reasons, most people will know a star is a single point. no more information will be revealed by the lack of coma

LOL! So if I took a picture of you and your eyes were reshaped by aberrations you wouldn't mind? What if I took a picture of your house and all the windows became round - is that OK too? ;-) No, if you are going to print large, you cannot have bad coma and I don't want to crop a 20mm shot to a 28mm to get rid of it so I have to look for a lens that is acceptable.

@senecrossing: You are right about a tracking head, I want to do nightscapes not purely astrophotography so a tracking head is not the answer for me.

sevencrossing

LOL! So if I took a picture of you and your eyes were reshaped by aberrations you wouldn't mind?

to greater or lesser extent all lenses suffer from aberrations
It is matter of what is and what is not acceptable
could you post some examples of bad and acceptable coma
Your STARLIT WRECK looks pretty good to me

spraynpray

I agree, it is always what the individual finds acceptable. That very difference between us is what keeps the commercial world going round and round. In this particular case, I am not prepared to accept less than the best I can get (within reason) as it is an area of great interest to me.

If you look at that image, the largest size on Flickr is only 513x768 which is exactly the point I made earlier - that particular image is the product of simple settings: 15sec, f4 and ISO 51200(!). If I put it up at 6000x4000 it would be a star trail at 15 seconds and the coma and hi ISO would show up more. I am developing a workflow which will give me the ability to print 24x16 or larger but it is a lot more involved, takes far more time and requires the best lens I can get hold of because I will have to replace the stars that show coma with ones that don't (call me bonkers if you like).

WestEndFoto

I am looking forward to seeing the outcome of your project Spraynpray.