New RF 14-35 f4L, anyone tried?

Good morning wet photographers,

I recently got a new Canon RF 14-35mm and wanted to use at 14mm underwater in my freedives (<10m)! Looks great!

So I will need to buy a dome, having the 6'' and 8'' options. The 6'' is cheaper and much easier to carry on a trip because it's small and I travel a lot.

Will I notice a difference in the image quality, especially in the corners of the photo? What's your experience? Tell us your review!

Thank you very much for your attention!

Fullframe at 14mm and a 6" dome will have really soft corners. 8" might still be problematic to be honest.

20 minutes ago, hyp said:

Fullframe at 14mm and a 6" dome will have really soft corners. 8" might still be problematic to be honest.

Thanks for your help, I don't know how to check this! 8'' will be a problem just to travel (and more expensive) but looks the way to go?

Really, you need the biggest dome possible for that setup, which goes against the grain for both free diving and travel. 

If you're shooting animals in the blue, not so much of an issue, but it will be poor for reefs etc. 

Only small option would maybe be the 8-15mm and 1.4x converter which may be decent behind a smaller dome

Mike

1 minute ago, pooley said:

Really, you need the biggest dome possible for that setup, which goes against the grain for both free diving and travel. 

If you're shooting animals in the blue, not so much of an issue, but it will be poor for reefs etc. 

Only small option would maybe be the 8-15mm and 1.4x converter which may be decent behind a smaller dome

Mike

You mean, it's poor for where corners are important, right? I thought 14 mm would be a dreamy lens for underwater maybe it was my bad!

Yep, there are some fantastic lenses that for some reason don’t work well underwater - Nikons 14-24 is the classic example.

Given the correct extension behind the port, your lens will likely be good in the centre but will really struggle if sharp corners are important in your shots


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Some people consider a 230mm dome marginal for a 14mm rectilinear lens and even in that dome are stopping down to f11-16 to get better corners.   If you are looking at rectilnear lenses then with a 6"dome something like an 18-20mm lens might have OK corners. 

Here is a sample of a 17mm lens behind a 170mm dome at f8:

https://uwaterphoto.com/?p=839

the 14mm will be significantly worse than this even stopped down.

If you want something really wide a fisheye lens like the 8-16 or a Sigma 15mm on adapters works well with smaller domes.

I just found this review https://www.uwphotographyguide.com/canon-rf-14-35-lens-review 

Quote

"This is because a dome port makes the corners in your image soft when you shoot a rectilinear lens. While this still happened with my 8 inch compact dome port (especially at 14-20mm), it's clear that the RF lens mount does keep the corners sharper than EF rectilinear lenses. Moreover, once you zoom in past 20mm, you hardly notice the corner softness. I was happy shooting reefscapes that I normally would have avoided with an EF lens."

Looks I really will have to go to 8'' instead of 6'' unfortunately.. I would love it more small and light to travel!

6 hours ago, stillviking said:

I just found this review https://www.uwphotographyguide.com/canon-rf-14-35-lens-review 

Looks I really will have to go to 8'' instead of 6'' unfortunately.. I would love it more small and light to travel!

You will notice that they are shooting at f14-18, that is probably the biggest factor in getting the corners sharper not counting the important fact that all of the reef shots are taken at 35mm where the corner softness won't be a problem.  The only shots at 14mm are a very soft whale and the seal where you can't see the corners.  Potentially a rather misleading review.

I don't agree with the premise that it's due to shorter RF flange distance.  This might produce sharper images on land, but it doesn't change how it interacts with a dome port.   Without sample images with corner detail taken at 14mm it's hard to say what is going on.

What an appalling, dishonest and misleading review! 

My guess is the lens doesn't work at 14mm or at realistic f stops, so they fudged it...to persuade people to buy one. All the optical advantages in the world will have no benefit if the lens doesn't work behind a dome. I agree the flange distance offers some optical advantages, but to claim that shooting a lens at f/18 in any way illustrates this is really stretching reality...

To return to the OP's question:

There is a ton of information here on Wetpixel about rectilinear wide angle lenses, but the crash course is:
1. To get sharp corners, you need a big dome. Even 8" is marginal.
2. Some rectilinear lenses do not work well behind any dome port.
3. The only way to know is to shoot the lens behind a dome port at realistic apertures.

Sadly, without someone testing it at realistic apertures and publishing the results, there is no way of knowing. Until then @ChrisRoss's advice about the 8-15mm and an adaptor is probably the best advise.

Thanks for your feedback!

For sure the f-stops used in this review are not realistic, however it was the only review I found until today, that's why I was looking if someone had tried it too.

I already have the RF 14-35 (my landscape lens). A dome + 8-15 mm is too much money for me now. Now I really don't know if I risk order the dome to use with 14-35 mm (and yes.. looks it need to be the 8'' at least for your feedbacks!).

I don't have an easy (or inexpensive) answer.

My suggestion would still be to buy, borrow or hire an 8-15mm. The risk you run with your 14-35mm is that you will invest in a big dome, and it does not work...in which case you have spent lot of money. The 8-15mm can be used with smaller cheaper domes.

To further pile on the bad news...big acrylic domes tend to be very buoyant. Given that you mention you are free diving, I think this will present a big problem. So this pushes you toward big glass domes...which are even more expensive. 

 

1 hour ago, adamhanlon said:

I don't have an easy (or inexpensive) answer.

My suggestion would still be to buy, borrow or hire an 8-15mm. The risk you run with your 14-35mm is that you will invest in a big dome, and it does not work...in which case you have spent lot of money. The 8-15mm can be used with smaller cheaper domes.

To further pile on the bad news...big acrylic domes tend to be very buoyant. Given that you mention you are free diving, I think this will present a big problem. So this pushes you toward big glass domes...which are even more expensive. 

 

You might be right the "buoyant" can turn in a big problem!

Some years ago I tried to use a Canon 7D + Sigma 10 mm Fisheye in a 4'' dome, it was very good to swim but had 2 problems: corners were VERY mushy and noise in high ISOs. Nowadays I also own a Canon 7D Mk2 backup camera, after read your tips, I was thinking if:

Canon 7D Mk2 + Sigma 10 mm Fisheye + 6'' dome (just had to buy the dome, 4'' was not a good experience in corners) would be a better setup than Canon R + RF 14-35 + 8'' dome (that I also would have to buy)?

Ofc these are "low cost" options for me now, the 8-15 must be the perfect match, but no money to invest.

1 hour ago, stillviking said:

Thanks for your feedback!

For sure the f-stops used in this review are not realistic, however it was the only review I found until today, that's why I was looking if someone had tried it too.

I already have the RF 14-35 (my landscape lens). A dome + 8-15 mm is too much money for me now. Now I really don't know if I risk order the dome to use with 14-35 mm (and yes.. looks it need to be the 8'' at least for your feedbacks!).

presumably you have the camera and housing already as you are only talking about a dome?  Do you have other ports or lenses you could use?

An 8" ikelite dome is not that expensive, though you'll also need the correct extension.  You could likely  use this lens in the 18-35mm range with reasonable corners with an 8" dome, because of the way dome port optics work as your angle of view reduces the corner problem reduces.  Exactly how far you would need to zoom in to get corners probably depends on your standards.  But this is only a guess. 

Also be aware the ikelite compact dome port is very shallow so will not place the lens entrance pupil correctly, you'll need the big dome to have a chance of achieving this.  The compact dome has worse corners than the the full size dome due to not placing the entrance pupil at the dome centre of curvature.

The 7d II could be an option as could using a sigma 15mm fisheye in a 6" dome with your full frame.

21 minutes ago, ChrisRoss said:

presumably you have the camera and housing already as you are only talking about a dome?  Do you have other ports or lenses you could use?

An 8" ikelite dome is not that expensive, though you'll also need the correct extension.  You could likely  use this lens in the 18-35mm range with reasonable corners with an 8" dome, because of the way dome port optics work as your angle of view reduces the corner problem reduces.  Exactly how far you would need to zoom in to get corners probably depends on your standards.  But this is only a guess. 

Also be aware the ikelite compact dome port is very shallow so will not place the lens entrance pupil correctly, you'll need the big dome to have a chance of achieving this.  The compact dome has worse corners than the the full size dome due to not placing the entrance pupil at the dome centre of curvature.

The 7d II could be an option as could using a sigma 15mm fisheye in a 6" dome with your full frame.

 

Yes, my current kit is:

Cameras: Canon R and Canon 7D Mark II (I was using as backup only),

Lens: Sigma 10 mm fisheye, RF 14-35 and 2 pancakes: 24 mm 2.8 and 40 mm 2.8 I use for portraits and street.

Ports: Dome 4'' and 1 flat for pancakes.

I tried before the dome 4'' with 7D + Sigma 10 mm but corners where really bad.

OK-well how about a Tokina 10-17mm fisheye (second hand so relatively inexpensive) with either your 4" or a 6" dome. These could be acrylic domes so no problems with buoyancy. There will be some optical compromise with the small dome, but I would try it out with the Tokina before buying the bigger dome as you may find that it works OK. 

You may need an extension ring for your housing. Tokinas typically need 10-20mm of extension, but check with your housing supplier. Terchically, you would need a zoom gear too, but mine just often gets put on 17mm and stays there! To be fair, the 10mm end is quite usable. 

I just found a new RF 14-35 underwater review with decent f-stops! Looks great:

https://www.ikelite.com/blogs/reviews/my-first-dive-with-the-canon-rf-14-35-f-4l

It looks horrible at f/8....

The corners are mush. He even admits it:

"At 14 mm even moderately-sized coral mounds appear to tower above the rest of the reef. Shot wide-open, the RF 14-35 is sharp at the image center and expectedly out of focus towards the edges"

To stress, what he describes as "out of focus" is due to depth of field issues. It is not an issue with focus. In this review, the (extreme) corner softness will be compounded by the fact that he is using it with an 8" port and his choice of very large apertures. It would be somewhat unrealistic to expect it to perform well with these two parameters.

To make an effective judgement, you want to be looking for results from it at f/11 and above with a large (230mm) dome. 

While not helpful in the short term, I have a 230 dome and housing on order to use with the 14-35.  I will post results when I get it underwater, which will be in a few weeks. I decided to give that setup a go as even if the 14mm is not great behind a dome, if it is solid from 16-35 on a full frame mirrorless it is a good choice for R series canon.  But I will report back here, if that is the case when I get it underwater.

So if you are not in a rush, I can provide the information you want.

14 minutes ago, ColdDarkDiver said:

While not helpful in the short term, I have a 230 dome and housing on order to use with the 14-35.  I will post results when I get it underwater, which will be in a few weeks. I decided to give that setup a go as even if the 14mm is not great behind a dome, if it is solid from 16-35 on a full frame mirrorless it is a good choice for R series canon.  But I will report back here, if that is the case when I get it underwater.

So if you are not in a rush, I can provide the information you want.

That would be awesome, thank you!!