# 16-35 f/2.8L III for astro?



## amorse (May 30, 2018)

Hi everyone, 

I do a fair bit of back country hiking and photography, but I am finding my legs just don't want to carry me that far with my current kit. Looking for options to lighten/shrink the load, and I'd be curious to hear your opinions on the best path forward.

Right now I am carrying a 5D mk IV, Canon 16-35 f/4L, Canon 24-70 f/2.8L II (or a 24-105 f/4L), sometimes a Canon 70-200 f/2.8 L II, and definitely a Rokinon 14mm f/2.8 in addition to a LEE filter system and a manfrotto 055 carbon fibre tripod. Obviously, this is way way too much when combined with camping gear, food and clothing. I'd estimate that I am shooting probably 50% of the time with the 24-70, 35% with the 16-35, 10% with the 14, and 5% with the 70-200, and the really only times I'm at f/2.8 is on the 14mm (for what it's worth).

Right now I am thinking that my best compromise (without changing what I shoot) may be to replace the 70-200 f/2.8L II with a 70-200 f/4L (really curious to see what comes from the announcement next week), and look for a different wide angle option which can both take the LEE filter system and can produce decent wide astro photos (i.e. replacing the 16-35 f/4L and the Rokinon 14mm f/2.8 with a Canon 16-35 f/2.8L III). 

So I have three questions:
[list type=decimal]
[*]How well does the Canon 16-35 f/2.8L III perform for astrophotography? I have heard that it really struggles with vignetting at 2.8 which could pose a barrier to some of the wide milky way stitches I've been doing (example here: https://www.flickr.com/photos/[email protected]/42095824811/in/dateposted-public/). Anyone have any thoughts on whether the vignetting issue is overblown?
[*]Are there any other zoom lens options that are at least 16mm at the wide end, with a traditional filter thread that would accept the LEE 100mm filter system?
[*]Any other suggestions to reduce the weight that I haven't considered?
[/list]

Any input would be greatly appreciated!


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## ahsanford (May 30, 2018)

I've never used it for astro, but 16mm @ f/2.8 has some ridiculous vignetting (over 4 stops) and the coma testing I've seen is not best in class. That said, I don't shoot astro and defer to those that do.

As for anything around 16 that works with the Lee 100 setup, it's a pretty short list. Canon's three 16/17-something UWA L zooms, RokiBowYang has a 16mm f/2, Tokina has a 17-35 f/4, and maybe one of the various RokiBowYang 14mm primes allow filters (I'm not sure). 

Keep in mind the Lee 100 setup kind of goes to hell wider than 16mm for vignetting (hardware in frame) problems. Step up to the outriggered systems like the SW150 II / Wonderpana / NiSi 180 and your list of wide lenses increases -- but that comes with other headaches (size/cost of everything goes up).

- A


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## amorse (May 30, 2018)

ahsanford said:


> I've never used it for astro, but 16mm @ f/2.8 has some ridiculous vignetting (over 4 stops) and the coma testing I've seen is not best in class. That said, I don't shoot astro and defer to those that do.



Thanks for this - this is what I was afraid of. Although in all fairness, the Rokinon I'm currently using doesn't look to be that much better in terms of vignetting so I wonder if this would really be the biggest issue!


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## ahsanford (May 30, 2018)

amorse said:


> ahsanford said:
> 
> 
> > I've never used it for astro, but 16mm @ f/2.8 has some ridiculous vignetting (over 4 stops) and the coma testing I've seen is not best in class. That said, I don't shoot astro and defer to those that do.
> ...



There are so many threads here of folks lamenting why a coma-free, vignetting controlled 16mm f/1.4 lens isn't available for astro that it cracks me up.

[ultra-fast] + [ultra-wide] + [coma-free] + [reasonable vignetting] lenses don't really exist, but each time a new UWA lens comes out, people get their hopes up. I hope folks get the great astro lens of their dreams, but nailing those four parameters above simultaneously is a very tall order.

- A


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## ethanz (May 30, 2018)

This may be a dumb question, but why not use the 16-35f4 for astro? Also yes, getting rid of the 70-200f2.8 in favor of the f4 is good. So much lighter and still a good quality lens if you don't need 2.8.


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## NancyP (May 30, 2018)

Many people like the Tamron / Ricoh-Pentax 15-30 f/2.8 for astro-landscape.

Why not 16-35 f/4? photons. You want as many as you can get! f/4 is disappointing in single-shot astro-landscape photography. If your camera is stationary, the stars cross pixels with the Earth's rotation, so you are limited in intensity per pixel. Usually people want lots of photons on the same pixel for getting the round star image, not a few photons per pixel from a linear star image (short star trail). If your camera rotates to keep the star stationary on its pixel, your terrestrial landscape is blurred. Many people composite their astro-landscape photos: one exposure optimal for terrestrial landscape, then start the rotating mount on its way and collect many 15 second to 1 minute exposures, and average those exposures taken on the rotating mount.

This gives more detail than most sites:

http://www.clarkvision.com/articles/characteristics-of-best-cameras-and-lenses-for-nightscape-astro-photography/


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## ahsanford (May 30, 2018)

ethanz said:


> This may be a dumb question, but why not use the 16-35f4 for astro? Also yes, getting rid of the 70-200f2.8 in favor of the f4 is good. So much lighter and still a good quality lens if you don't need 2.8.



Not a dumb question. Short answer is that astro tends to live at the widest aperture possible -- these folks need f/2.8 (or faster).

The nice wide astro landscapes you might have seen before require an instrument that can soak up as much light as possible, and the usually require high ISO + wide aperture + a capped ceiling on how long you can leave the shutter open without the stars appearing to move in the picture. That last bit is critical: you can't just use a slower lens and leave the shutter open 2x as long, so it changes your normal exposure triangle options.

And using f/4 instead of f/2.8 means an instrument that is bringing in 1/2 the light of the other. So, sure, you can shoot astro with an f/4 lens, but you'll need to either double your ISO (already really high!) or underexpose and have to push the shot in post (something I've never had great success with).

No pun intended, but it would appear the term 'the lens is brighter' (for a faster max aperture) is quite literal in the case of astro. 

- A


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## Don Haines (May 31, 2018)

There are a lot of sigma art lenses at F1.4...... I kind of like the 20mm......


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## NorbR (May 31, 2018)

amorse said:


> Anyone have any thoughts on whether the vignetting issue is overblown?


In my opinion, yes it is overblown. 

Vignetting is the main flaw of the 16-35L III, for sure. But it's on par with many other wide lenses. The (original) Samyang 14/2.8, universally praised as a great ultra-wide astro lens, has the same levels of vignetting (if anything, slightly higher levels):
https://www.the-digital-picture.com/Reviews/Lens-Vignetting-Test-Results.aspx?FLI=0&API=0&FLIComp=0&APIComp=0&Lens=1073&Camera=979&LensComp=1059

Zeiss lenses, also often recommended, the 15/2.8 in particular, also come with similar levels of vignetting (the 21/2.8, the only one I've used, is slightly better):
https://www.the-digital-picture.com/Reviews/Lens-Vignetting-Test-Results.aspx?FLI=0&API=0&FLIComp=0&APIComp=0&Lens=1073&Camera=979&LensComp=794

In the end, it's like ahsanford said, the perfect wide astrophoto lens has not been invented yet. You have to pick your poison. For the 16-35L III it's vignetting. For the Tamron it's the inability to use filters. For the Sigmas it's usually coma. Choose the one that bothers you the least, and roll with it. But in terms of vignetting, anything you can do with the Samyang, you can do just as well with the Canon.


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## amorse (May 31, 2018)

ahsanford said:


> [ultra-fast] + [ultra-wide] + [coma-free] + [reasonable vignetting] lenses don't really exist, but each time a new UWA lens comes out, people get their hopes up.



Definitely. For me, the one need which really seems to sink the desire is the regular filter thread. If I didn't need that I could likely get away with the Sigma 14-24 or the Tamron 15-30.


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## amorse (May 31, 2018)

Don Haines said:


> There are a lot of sigma art lenses at F1.4...... I kind of like the 20mm......



Oh definitely! If I wasn't at all worried about weight/price/size I'd probably be looking at the Sigma 14 f/1.8 - loads of great options out there. To be fair though, even if I did replace the Rokinon 14/2.8 and the 16-35 f/4 with just the 16-35 f/2.8L III, I'd still only be saving myself 375g of packed weight (and spending a fair bit of money in the process).


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## amorse (May 31, 2018)

NorbR said:


> amorse said:
> 
> 
> > Anyone have any thoughts on whether the vignetting issue is overblown?
> ...



Thanks for the input - I think maybe I'll rent the 16-35 and give it a swing. You're absolutely right that there doesn't appear to be any home run options out there with my criteria, but if the vignetting is comparable between the Rokinon and the Canon, then the Canon could be a reasonable compromise.


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## 20Dave (May 31, 2018)

Perhaps more hassle than you want to deal with, but most astro-imaging software has the ability to correct for vignetting if you take what is called a "flat frame" (basically a photo of a uniformly illuminated field) and calibrating your real image with the flat frame. Maybe you can do that with Photoshop as well, but I've never tried it. There are many astro-imaging software apps out there, all over the place in terms of cost and feature set. 

A good one to start with if you are interested that's not too expensive is Nebulosity from Stark Labs. It can likely control your camera to take the images and then process the images as well. I used to use it when I was taking astro photos with my 20D back in the day. I have since moved on to a dedicated astro camera and PixInsight as the processing software, but that is getting way more complicated than you are looking for.


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## Don Haines (May 31, 2018)

amorse said:


> Don Haines said:
> 
> 
> > There are a lot of sigma art lenses at F1.4...... I kind of like the 20mm......
> ...




This is with the Sigma 20mm from a canoe trip last fall..... Shooting at F1.4 lets me keep the shutter speed fast enough to avoid star trails and still keep a reasonable ISO....


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## Ah-Keong (May 31, 2018)

Have you considered Sigma 14mm f/1,4 Art?


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## amorse (May 31, 2018)

Don Haines said:


> amorse said:
> 
> 
> > Don Haines said:
> ...



Beautiful photo. No doubt the 20mm can do a wonderful job of astro, but I'm not sure it could replace both my 14mm 2.8 and my 16-35 f/4 while still taking the LEE 100mm filter system which is my principle objective in an effort to reduce kit weight for long hikes. Last year I did a number of multi-day hikes which became just punishing and I made peace with the fact that I need to reduce my pack weight.


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## amorse (May 31, 2018)

Ah-Keong said:


> Have you considered Sigma 14mm f/1,4 Art?


I have - it looks to be a very capable lens for astro (and I'll admit it is very tempting), but my objective is to reduce my lens kit by one lens and reduce total weight so that I can hike further. It seems like the only way I can do this while still using filters is to aim for the 16-35 f/2.8L III which would let me drop my 16-35 f/4 and the Rokinon 14 f/2.8. All the other options out there are either too slow, or don't have a filter thread it seems.


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## ahsanford (May 31, 2018)

The OP said it had to support the Lee 100 system, so it's gotta have filter threads and a removable hood. 

So the following lenses are all a no-go:

Sigma 14 / 20 / 14-24 / 12-24
Canon 11-24 / 14 / TS 17
Most of (all of?) the RokiBowYang 14 primes
Tamron 15-30
Zeiss 15mm (old version: has threads but the hood is fixed)
Tokina 16-28 
Irix 11

And the following lenses are still on the table (presuming longer than 24mm is out, 24-70/105s removed):

Canon 16/17- zooms / 20 / 24 1.4 / 24 2.8 IS / TS 24
Canon TS 24
Zeiss Milvus 15* / 18 / 21 (MF may be a non-starter for your other uses for this lens)
Irix 15* (MF again)
Sigma 24 / 24-35
Samyang 24 1.4 / TS 24 (MF again)

*not sure they sell a Lee ring in the 95mm diameter that is 'WA' style, worth verifying they do before you buy or you may vignette really hard on those lenses.

I'm sure I've missed a few (please chime in!), but that's more or less the list to work with. I don't shoot astro, but for the jack of all trades wide lens you are talking about, the 16-35 f/2.8L III is clearly the pick of the litter: f/2.8 for astro, sharp as a katana, sealed for your outdoor adventures, and it has AF you can rely on (in fairness, I think Sigma's AF is A-OK here at these FLs). Downsides: weight, cost and vignetting for astro.

But there are other options on that list you can sift through if AF, f/2.8 or the need to zoom is not a must.

- A


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## basketballfreak6 (Jun 25, 2018)

amorse if you're willing to part with the cash, Nisi make filter holders for lenses with bulbous front elements, allowing you to use 2 square slot in filters + CPL, but they're of the 150mm variety which is obviously more expensive and bigger, but as someone that came from using Lee and Singh Ray filters in the past i can vouch for the quality of Nisi filters, it's my preferred brand now over the other 2 more expensive options

on that note i am using the sigma 14 art for mw landscape and it is a phenomenal lens, sharp across the frame wide open (until you get to the very corners where a bit of field curvature kicks in i think anyway), there're definitely some coma and astigmatism again in the corners but to me it's quite mild and are of no practical concern (YMMV, of course), distortion is extremely well controlled, vignetting doesn't seem too bad and it's a pretty liberating feeling to be able to shoot that wide and that fast


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## BillB (Jun 25, 2018)

In response to the OP's question 3, the 16-35 F2.8 III and the 24-70 F2.8 II are both very good lenses, but they are both heavy and there is a lot of overlap. So, one question might be how important is it to close the gap between 35 and 70, figuring in the possibility of zooming with your feet, stitching and cropping.


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## Frodo (Jun 25, 2018)

BillB said:


> In response to the OP's question 3, the 16-35 F2.8 III and the 24-70 F2.8 II are both very good lenses, but they are both heavy and there is a lot of overlap. So, one question might be how important is it to close the gap between 35 and 70, figuring in the possibility of zooming with your feet, stitching and cropping.



Or the overlap between 14 and 24?
I remain happy with my Samyang 14/2.8, especially because of the lack of coma and its pretty sharp wide open. Photoshop corrections remove distortion and vignetting (with a little extra noise).
Looking at your shooting stats and your current kit, I'd take the 14/2.8 and 24-105/4 hiking. I do. This covers most things for modest weight.
This option is probably the lightest weight. And the cheapest!


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