Sony 20 mm - 70 mm f4.0 G for UW?

I can see nothing unconventional or even contentious in the following statement. I read that he is simply stating that he wants to see how the lens works in "real world" conditions before making a decision. It also stated as an opinion, so cannot be seen as "unconventional," "dismissive" or in any way "diminishing." He is simply disagreeing with you, not stating that you are wrong....

1 hour ago, Interceptor121 said:

As to how well the new Sony 20-70mm lens may work for certain shooters I'll wait for Phil's zoom gear testing plus manufacturer's advice and real world shooting versus calculated measurements.

1 hour ago, Interceptor121 said:

Perhaps going forward I should just keep my considerations to myself as otherwise there is a risk that this is not even welcome simply because someone can't understand the logic and neither I want things to become a lecture and spend to much time explaining myself

Kind of sums up the issue. I am truly sorry that you feel the Wetpixel community is unable to "understand" your logic. If this is the way you feel, perhaps your insights might be better shared in a venue that can do so. 

Your decision.

On 3/8/2023 at 1:55 AM, Interceptor121 said:

Images do not look good at all

I think your extension is way too long the 230 port has a field of view of 140 degrees while the lens has 94 degree using vignetting as a criteria is not going to help

#1-THIS RESPONSE IS LIKELY BASED ON AN ASSUMPTION AS 121 HAD NO IDEA WHAT HOUSING BRAND, PORT BRAND OR EXTENSION BRAND I WAS USING. SO I WOULD ADD MAKING ASSUMPTIONS TO ADAM'S LIST.  

You can try a shorter one in a bathtub without even going to the pool and see if it is preserving or not the field of view
With this system you would have saved yourself two trips to the pool

#2-MANSPLAYING (A TERM GENERALLY USE WHEN A MAN IS TAKING TO A WOMEN) 121 HAS MANSPLAINED TO ME THAT I CAN AVOID GOING TWICE TO THE POOL BY TESTING MY EQUIPMENT IN A BATHTUB AS IF HE KNOWS ME.

FIRST I HAVEN'T USED A BATHTUB SINCE I WAS A CHILD AND SECOND I HAVE A POOL IN MY BACKYARD ABOUT 30 FEET FROM MY OFFICE. TODAY THE WATER TEMPERATURE IS 82 DEGREES FAHRENHEIT AND THE AIR TEMP IS 86 DEGREES. SECOND I THOROUGHLY ENJOY MY POOL AND USE IT SEVERAL DAYS A WEEK. I CAN ALSO WALK TO THE INTRACOASTAL  WATERWAY FROM MY HOUSE OR DRIVE TO THE BLUE HERON BRIDGE IN ABOUT FIVE MINUTES FOR TESTING SO WHY WOULD I WANT TO WASTE WATER FILLING A BATHTUB.     

There is more without this you will now go back with 60mm and conclude that works because it doesn’t vignette but that is incorrect too and your angle of view will be reduced

#3 121 HAS ALSO ASSUMED A CONCLUSION FOR ME ABOUT WHAT I THINK WILL OR WON'T WORK WITH THIS LENS.

You can keep doing the same things for any number if years you want but ultimately this is physics
Even in physics you do observation but the purpose of theory and model is to reduce them to the minimum so you don’t have to go back to the drawing board every time

#4 IT APPEARS IN THIS STATEMENT THAT 121 AGAIN ASSUMES THAT I AM NOT AWARE THAT PHYSICS ARE INVOLVED IN THIS PROCESS.

Of course is your prerogative to use your own time as you wish as well as define your own level of quality you are satisfied

#5 THANK YOU 121  FOR ACKNOWLEDGING THAT I AM ALLOWED TO USE MY TIME ANYWAY I LIKE.

 
For clarity once you know the lens design you need trigonometry which is year 11 in UK 10th grade in US
This is not advanced science

#6 121 IS CORRECT THIS IS NOT ADVANCED SCIENCE AND THE POSSIBILITIES ARE LIMITED TO WHAT PORT YOU CHOSE FOR THIS LENS AND A CHOICE OF EXTENSIONS THAT AT BEST ARE IN 5MM INCREMENTS. NOT THAT ITS ANYONES BUSINESS BUT I NEVER LIKED MATH DURING MY SCHOOL YEARS AND NEVER WENT BEYOND ALGEBRA MUCH TO THE CHAGRIN OF MY PARENTS WHO WERE BOTH ENGINEERS MY THREE SISTERS AND I ALL HATTED MATH. THIS IS WHY I DON'T HAVE ANY INTENTION TO USE TRIGONOMETRY AND WHY IT GIVES ME A MIGRAINE. I APPLAD THOSE WHO FIND TRIGONOMETRY INTERESTING BUT I AM NOT ONE OF THEM AND HAVE GOTTON ON FIND WITHOUT USING IT AS A TESTING RESOURCE.     


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Since most of the comments in question were in my posts I would just like followup with a response since my friend David Haas and Adam have gotten involved in one way or another. In this thread and another I did not post in Adam pointed out that 121's remarks were overly aggressive, argumentative, dogmatic and hectoring. To me they make several unfounded assumptions and and give the impression 121 knows me in some way which could not be further from the truth. 

First I will go back to my original comments meant for the original poster who was interested to know it anyone had used this lens. My response was yes I am in the process of testing the lens with a 230mm port and 70mm of extension. I also described what I thought the advantages of the 20-70 over the more common 24-70 and 28-70 loses could be. Above in all caps are my responses to 121 some of which are the subject of Adam's post above..

@Interceptor121 thanks for the reference to photonstophotos -- I have only had a chance to browse it for a few minutes, and it seems to be a treasure trove. Appreciate it.

Apropos to the debate here, I haven't too much insightful to add - having been in the education field for a long time, I am finding that many humans respond better to an approach that we call the experiential learning model. Here the idea is to first "just do it" (a quick and rough prototype), and then, when the design fails (and it does, haha), analyse the failure, look up the theory, make a model, solve it and use the solution to drive the next iteration.. I feel like I could see shades of this approach (as contrasted to the purely liberal approach used in most of our universities today) in this discussion. Just my two cents,

Kind regards

Ajay 

9 hours ago, Phil Rudin said:

 

Since most of the comments in question were in my posts I would just like followup with a response since my friend David Haas and Adam have gotten involved in one way or another. In this thread and another I did not post in Adam pointed out that 121's remarks were overly aggressive, argumentative, dogmatic and hectoring. To me they make several unfounded assumptions and and give the impression 121 knows me in some way which could not be further from the truth. 

First I will go back to my original comments meant for the original poster who was interested to know it anyone had used this lens. My response was yes I am in the process of testing the lens with a 230mm port and 70mm of extension. I also described what I thought the advantages of the 20-70 over the more common 24-70 and 28-70 loses could be. Above in all caps are my responses to 121 some of which are the subject of Adam's post above..

 

 

Re maths, exactly, some people prefer to relate to problems from a theoretical perspective other like to test things in a practical manner.    Both approaches are fine and each to their own preference.  In the end it will need to be tested anyway.  I have found vendors deviate from the theoretical positioning for some lenses and my understanding is that at least some vendors are setup with macro sliders where they can test the lens to come up with the final positioning.  

If someone is prepared to take the time to try out these new lenses and share the results we should all be thankful no matter which approach they take to get there.  Ideally in this forum we can all can learn from both approaches by considering the views of everyone without any form of finger pointing

[mention=34353]Interceptor121[/mention] thanks for the reference to photonstophotos -- I have only had a chance to browse it for a few minutes, and it seems to be a treasure trove. Appreciate it.

Apropos to the debate here, I haven't too much insightful to add - having been in the education field for a long time, I am finding that many humans respond better to an approach that we call the experiential learning model. Here the idea is to first "just do it" (a quick and rough prototype), and then, when the design fails (and it does, haha), analyse the failure, look up the theory, make a model, solve it and use the solution to drive the next iteration.. I feel like I could see shades of this approach (as contrasted to the purely liberal approach used in most of our universities today) in this discussion. Just my two cents,
Kind regards
Ajay 

Marelux has now updated the port chart for Sony lenses and added the Sony FE 20-70mm F/4 with zoom gear #51109. With the 230mm port they have recommended a 60 extension and a 50 extension with the 180mm dome port. I have now tried both and I really like the 180mm port for my local diving. Marelux has sent me a 15mm extension which arrive next week so I may try 5mm over/under just for fun.

Nauticam updated the Sony chart on 3/14 and while the 20-70 has not been added they have added the WACP-1 with the new Sony FE PZ 16-35mm F/4. This allows a zoom from 28-35 for a converted FOV from 130-109 for those who think the  28-60, 28-70 and 28mm F/2 don't have good enough IQ. The combination requires the N120 10mm/10mm II extension. Prior Sony 16-35 lenses only worked with the expensive and heavy WACP-II.

22 minutes ago, Phil Rudin said:

Marelux has now updated the port chart for Sony lenses and added the Sony FE 20-70mm F/4 with zoom gear #51109. With the 230mm port they have recommended a 60 extension and a 50 extension with the 180mm dome port. I have now tried both and I really like the 180mm port for my local diving. Marelux has sent me a 15mm extension which arrive next week so I may try 5mm over/under just for fun.

Nauticam updated the Sony chart on 3/14 and while the 20-70 has not been added they have added the WACP-1 with the new Sony FE PZ 16-35mm F/4. This allows a zoom from 28-35 for a converted FOV from 130-109 for those who think the  28-60, 28-70 and 28mm F/2 don't have good enough IQ. The combination requires the N120 10mm/10mm II extension. Prior Sony 16-35 lenses only worked with the expensive and heavy WACP-II.

those recommendations make no sense.

the 230 port is almost an hemisphere while the 180mm port has an angle of view that is reduced the port is 83mm tall requiring always 2 cm more compared to the 230mm port

It looks like they are continuing to use vignetting as a criteria so of the two the 180mm port extension is the one that is nearer what is required. The 230 port should be 20mm shorter and 60mm is possibly way too long 30mm would be a better option if you had that port

Of course manufacturers know better except when they don't!

First of all I am just the messenger and secondly while I am sure you used advanced trigonometry to calculate the 30mm extension for the 230mm dome the lens approaching the 70mm end hits the back of the port glass. It seems to me that would be a bad thing so you may want to recalculate.    

1 hour ago, Phil Rudin said:

First of all I am just the messenger and secondly while I am sure you used advanced trigonometry to calculate the 30mm extension for the 230mm dome the lens approaching the 70mm end hits the back of the port glass. It seems to me that would be a bad thing so you may want to recalculate.    

180mm port depth 83 mm 230mm port depth 112 mm

83+50=133

112+30=142

I do not see how the lens would hit the 230 port before it hits the 180mm port

Besides both need the 35.5mm N100 to N120 port so add 35.5 and 25mm the port is recessed in the housing you get

133+35+25=193

142+35+25=202

Both dimensions are far away from the lenght of the lens fully extended

The 230 port is always deeper and physics normally works well and the reason why the 230 port needs to be longer is because the radius is 1cm longer however if this was 60 cm the combination would go to a whopping 232mm which is not required and will induce pincushion distortion

Edit I am now looking at the marelux port chart there is no 35mm port adapter in the port chart and the extensions look all over the place in some cases the two ports take the same extension in others one is longer than the other and then viceversa. Ouch!

Once again it does not appear that you bothered to read my post or even be in the ballpark because I was talking about the Marelux port chart not the Nauticam port chart. Nauticam posted new updates on 3/14 and they have not listed the Sony 20-70mm F/4.

If you are unaware Nauticam and Marelux are not the same company and they don't use the same extension lengths. 

Just now, Phil Rudin said:

Once again it does not appear that you bothered to read my post or even be in the ballpark because I was talking about the Marelux port chart not the Nauticam port chart. Nauticam posted new updates on 3/14 and they have not listed the Sony 20-70mm F/4.

If you are unaware Nauticam and Marelux are not the same company and they don't use the same extension lengths. 

I am now looking at the marelux port chart there is no 35mm port adapter in the port chart and the extensions look all over the place in some cases the two ports take the same extension in others one is longer than the other and then viceversa. 

The product look pretty much copies of Nauticam designs the dimensions are identical

I would not trust that port chart for any practical use it is inconsistent all over

30 minutes ago, Interceptor121 said:

I am now looking at the marelux port chart there is no 35mm port adapter in the port chart and the extensions look all over the place in some cases the two ports take the same extension in others one is longer than the other and then viceversa. 

The product look pretty much copies of Nauticam designs the dimensions are identical

I would not trust that port chart for any practical use it is inconsistent all over

So in am guessing that you just can't admit that you are wrong in making the assumption that I was not talking about Nauticam even though Marelux is the first word in my post and decided to instead attack Marelux products. I will not make the assumption that you have even held or seen a Marelux housing or that you any idea which Marelux housing I may have been talking about.

And just for others future reference Marelux only has one port mounting size (5 inch) for all of their current housings, further they use a bayonet port mount so a more like comparison would be housings like Aquatica, Isotta, Sea & Sea and so on. Further if you had looked closely at the Marelux port chart you would see they don't need a 35.5mm adapter because they are not moving between N100 and N120 sizes like Nauticam. You might have also noticed that the recommended Marelux flat macro port for the Sony 28-60 is a 32mm port while it is 45mm for Nauticam. Since I have actually use several Marelux and Nauticam housings I can say without reservation that they are both quality products with several differences as would be expected. 

You may also want to look at the Nauticam port charts for Sony and you will see that some lenses use the same port extension for two or three different port sizes so these recommendations are not uncommon or exclusive to Marelux.  

6 minutes ago, Phil Rudin said:

So in am guessing that you just can't admit that you are wrong in making the assumption that I was not talking about Nauticam even though Marelux is the first word in my post and decided to instead attack Marelux products. I will not make the assumption that you have even held or seen a Marelux housing or that you any idea which Marelux housing I may have been talking about.

And just for others future reference Marelux only has one port mounting size (5 inch) for all of their current housings, further they use a bayonet port mount so a more like comparison would be housings like Aquatica, Isotta, Sea & Sea and so on. Further if you had looked closely at the Marelux port chart you would see they don't need a 35.5mm adapter because they are not moving between N100 and N120 sizes like Nauticam. You might have also noticed that the recommended Marelux flat macro port for the Sony 28-60 is a 32mm port while it is 45mm for Nauticam. Since I have actually use several Marelux and Nauticam housings I can say without reservation that they are both quality products with several differences as would be expected. 

You may also want to look at the Nauticam port charts for Sony and you will see that some lenses use the same port extension for two or three different port sizes so these recommendations are not uncommon or exclusive to Marelux.  

It does not matter what port system you use. You cannot have the same lens having one time a longer extension for one dome and another lens shorter it does not make any sense. Your comment about the port chart difference between the nauticaj and this one simply means the camera is more recessed indicating less precision in the manufacturing process. If Nauticam is 25mm in this one is 38mm in.

Few examples of Marelux port chart

Sigma 24-70mm lens 180mm dome 80mm extension 230mm 70mm extension

Sony 27-70 lens 180mm dome 50mm extension 230mm dome 60mm extension

Sony 24-105mm 180mm dome 70mm extension 230mm dome 70mm extension

What would be the logic to make sense of those recommendations? The ports are physically the same and based on construction either one needs longer or shorter (equal is unlikely) cannot go around like this

It just shows that there is lack of rigour here besides most of those lenses have design details available so it is relatively easy to rectify if you know how to. If someone has any logic argument to make sense of the above example I look forward to an explanation

I believe a fundamental issue with rectilinear lenses especially not too wide is that the extensions 'suggested;' are many times totally off while for fisheye lens the rule go forward until it vignettes works much better. Those few example that work well are mostly out of coincidence not choice.

For the  Sony FE 24-105mm F/4 G it does not appear that Nauticam has support for this lens but Aquatica does and it uses extension 48459 with both 8 inch and 9.5 inch glass ports, Isotta has support for 24-105 they recommend a 90mm extension for the 6 inch, 6.5 inch, 8 inch and 9 inch ports and Marelux recommends the 70mm extension for both 180 and 230mm ports. 

For the Sigma 24-70mmF/2.8  DG DN Marelux recommends the 60mm extension for both 180 and 230 ports. 

For the Sigma 24-70 F/2.8 ART lens Marelux recommends the 80mm extension for both 180 and 230mm ports, (I am sure that it is quite possible that for the 230 port that Marelux simply made a mistake on the single (70mm) extension because if you look below at the combination of the 40mm extension with knob and the 40mm extension that adds up to 80mm unless my math is wrong). For the Sigma 24-70 ART Nauticam recommends the 55mm extension for the 8.5 inch, 180mm and 230mm ports. Nauticam has added the asterisk to the 230mm dome as being the best but not all can afford that port.

As far as your Sony 27-70mm lens, I would not want to accuse you of making another mistake so I will wait for that lens to be released I am sure you have some inside information that we don't.

I doubt seriously that we will see extensions in 1mm increments even though they may best possession a given port for best optimal use of a given lens. Until then people have been using these combinations and producing exceptional photos for decades.    

3 hours ago, Phil Rudin said:

For the  Sony FE 24-105mm F/4 G it does not appear that Nauticam has support for this lens but Aquatica does and it uses extension 48459 with both 8 inch and 9.5 inch glass ports, Isotta has support for 24-105 they recommend a 90mm extension for the 6 inch, 6.5 inch, 8 inch and 9 inch ports and Marelux recommends the 70mm extension for both 180 and 230mm ports. 

For the Sigma 24-70mmF/2.8  DG DN Marelux recommends the 60mm extension for both 180 and 230 ports. 

For the Sigma 24-70 F/2.8 ART lens Marelux recommends the 80mm extension for both 180 and 230mm ports, (I am sure that it is quite possible that for the 230 port that Marelux simply made a mistake on the single (70mm) extension because if you look below at the combination of the 40mm extension with knob and the 40mm extension that adds up to 80mm unless my math is wrong). For the Sigma 24-70 ART Nauticam recommends the 55mm extension for the 8.5 inch, 180mm and 230mm ports. Nauticam has added the asterisk to the 230mm dome as being the best but not all can afford that port.

As far as your Sony 27-70mm lens, I would not want to accuse you of making another mistake so I will wait for that lens to be released I am sure you have some inside information that we don't.

I doubt seriously that we will see extensions in 1mm increments even though they may best possession a given port for best optimal use of a given lens. Until then people have been using these combinations and producing exceptional photos for decades.    

it was a type 20-70 but again it makes no sense that port chart period

I don't need to bore you guys you are happy with what you have fine so be it

On 3/13/2023 at 1:34 PM, adamhanlon said:

For what it is worth, my experience is that lens performance behind dome ports is serendipitous rather than by design. I have not been able to discern from specifications whether a lens will work well or not, and have found that in-water testing is the only way to actually find out how lenses perform and to figure out extension lengths. In part, wide angle lens designers tend not to prioritise close focus performance.

I've tried asking lens manufacturers for data such as the positions of Principal Points and such like useful information which would help in theoretic computations, since these may be useful in approximating requirements. Unfortunately such requests seem to disappear into a blackhole meaning that lenses would need to be tested to determine the data required. All of which makes me think that often in-water testing is just as easy as trying to check and work things out any other way ......

31 minutes ago, Paul Kay said:

I've tried asking lens manufacturers for data such as the positions of Principal Points and such like useful information which would help in theoretic computations, since these may be useful in approximating requirements. Unfortunately such requests seem to disappear into a blackhole meaning that lenses would need to be tested to determine the data required. All of which makes me think that often in-water testing is just as easy as trying to check and work things out any other way ......

Patents exist as well as people that know how to present them

https://photonstophotos.net/GeneralTopics/Lenses/OpticalBench/OpticalBench.htm

Underwater manufacturers follow the same trial and error approach

When I asked Nauticam what they did they told me they use in water macro slide

In addition you can find the no parallax point of a lens using a tripod 3 posts and a slide mount

1 hour ago, Interceptor121 said:

Patents exist as well as people that know how to present them .....

I have a friend who is an optical designer. He uses software which can generate an enormous amount of data including predicted MTF graphs. But to do so he needs information. If you are going to waste lots of time using trial and error methods to provide such information you might as well simply use an in water macro slide in the first place. As you suggest. Its not rocket science.

I have a friend who is an optical designer. He uses software which can generate an enormous amount of data including predicted MTF graphs. But to do so he needs information. If you are going to waste lots of time using trial and error methods to provide such information you might as well simply use an in water macro slide in the first place. As you suggest. Its not rocket science:rolleyes:.

You are talking about two opposite

Someone that is trying too much to simulate stuff

And someone else who has nothing better than using a tool designed for macro to test domes whose only benefit is not to go in the water

It is clear that the results are suboptimal when I said they use a macro slide (for wide angle) doesn’t mean I think they are doing the right thing the opposite

Clearly when there is a competence gap it is difficult to appraise the difference between astrophysics and trigonometry so all sounds alien

But this is not astrophysics or quantum mechanics and many topside photographers have worked out how to overcome the lack of documentation it takes 20’ to work out. Panorama photographer do this since ever

If you know how to

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23 hours ago, Interceptor121 said:

You are talking about two opposite ......... If you know how to

 

I'm sorry but your post makes no snese to me. Perhaps someone else would like to explain it?