a6xxx Salted Line. Meikon. Lens compatibility

[Hector1959]

Reading the Meikon's website I do not really understand some remarks about lens compatibility. I mean particularly the mentions to "autofocus only" or "no manual focus". It would appear to be clear but I am little confused.
For example let's take the 4" Dry Dome Port:
Being the Samyang a manual focus lens I am prone to understand the the remark "No manual focus" refers to the fact that housing has no capacity to focus the lens manually. But then, you see lens Sony E 20mm and Sony E16mm both of which have autofocus that are "remarked" as "autofocus only" and "No manual focus" respectively.
Aditionnally while Sony E 20mm F2.8 marked as "autofocus only" is later marked "No manual focus" when combined with the Fisheye Converter VCL-ECF2 or the Ultra Wide Converter VLC-ECU2.

Any explainations?

Regards

 

[Barmaglot]

The zoom/focus knob is built into the housing, not the ports. The housing ships with two gears which fit onto lenses and engage a cog on the housing - one for Sony 16-50mm lens, and the other for Sony 10-18mm lens. The Sony 16-50mm lens has a single ring which is used to control zoom or focus, depending on the camera settings. The Sony 10-18mm has two rings - one for manual (non-power) zoom, and the other for electronic focus - the supplied gear fits onto the zoom ring, so there is no access to the focus ring inside the housing. All other lenses rely on automatic operation, although in some cases, it is possible to make something work - for example, I have a 7Artisans 7.5mm f/2.8 fisheye lens, which has no electronics whatsoever, but I was able to pad its focus ring with double-sided tape sufficiently to fit the zoom gear from 16-50mm lens and control focus this way, although I still have to pre-set the aperture before sealing the housing. I don't have either 16mm or 20mm lenses to test with, but if you desire manual focus in that scenario, it might be possible to make something work with the 16-50mm gear - or maybe not, depending on how things line up. In any case, aperture in electronic lenses is controlled via a camera body dial, and autofocus is generally very quick and accurate.
In other words, a 16mm or 20mm lens, with or without a fisheye or ultrawide adapter, will autofocus normally, but without custom modifications you will not be able to override autofocus with manual focus.

 

[Hector1959]

Barmaglot,
Thanks for your reply but that's not exactly what I am trying to clarify. It has to be with the phrasing used.
I know there are only 2 zoom / focus gears available. 16_50 and 10_18.
Additionally lens with AF are supposed to be focused vía camera In fact I am not looking for manual focus but being able to use the AF in a6300.
My point is why the make the same
remark "no manual focus" for Samyang 8 and Sony 16 while Samyang is manual lens and Sony Autofocus. Or why 20 mm is marked "Autofocus only" and lateral as "no manual focus" when combined with converters
It is confusing
Regards

 

[Barmaglot]

It's mostly the wording. With manual-only lenses, "no manual focus" means that you must pre-focus the lens before sealing the housing, while with electronic AF lenses, "no manual focus" means that you must rely on autofocus and can't override it in MF/DMF camera modes.

 

[Hector1959]

Thanks. And what is the difference to mark AF lenses as "autofocus only" in some cases and as "no manual focus" in others? Does it means that some AF lenses may not be autofocused from camera controls?
And, why the same lens marked as "autofocus only" becomes "no manual focus" when combine with a fisheye/wide angle convertor?
Regards

 

[Barmaglot]

There is no difference.
A6xxx cameras have five focusing modes, selected via Fn menu:

1. AF-S: single-shot autofocus; the camera focuses on what it recognizes as the subject and locks that focal distance.
2. AF-C: continuous autofocus; the camera tracks what it recognizes as the subject as it moves toward and away from the camera.
3. AF-A: automatic selection; the camera switches between AF-S and AF-C modes according to its internal algorithm.
4. DMF: Direct Manual Focus; the camera focuses as in AF-S, but then you can use the focus ring on the lens to adjust the focus manually.
5. MF: Manual Focus; the camera makes no attempt to autofocus, instead you set the focus distance by using the focus ring on the lens. Note that you can't remap focus control from the lens ring to any of the body dials or buttons. Unlike, say, Olympus cameras with power zoom lenses, you can't remap zoom to body buttons either.

The 16-50mm lens has only a single ring, so in AF-S, AF-C and AF-A modes, that ring will function as zoom only. In MF mode, that ring will stop zooming and start focusing; you can still zoom using a rocker on the side of the lens, but inside the housing, that rocker is inaccessible. In DMF mode, that ring will function as zoom until you engage focus (half-press shutter, or back button) at which point it will switch to focusing until focus is disengaged.
With any other lens (SEL1018, SEL16F28, SEL20F28, SEL30M35, SEL50M28, SEL90M28G, what have you), unless you do hardware mods in order to access the focus ring on the lens, you will only be able to use AF-A, AF-S and AF-C modes - MF will be useless, as you won't be able to spin the focus ring. DMF may be semi-useful for macro - you can have it lock initial focus, then engage magnification (blow up a small area of the image to cover the entire screen, so that you can more easily spot imperfections) and rock the camera back and forth to fine-tune the distance.

 

[Hector1959]

Barmaglot,
You've been very helpful and your posts have help me understand better the Meikon's wording.
I' am reseaching to decide what lens to buy and therefore which Seafrogs dome to buy.
Sony 10-18mm seems a very good option (better optics and zooming capability) but it is costly. With this lens I will have to by the 6" dome. So, I was thinking of 16mm + Fisheye converter in a 4" dome. Would it be a good choice?

Meikon's wording confuses me.
Of course, except the 16-50mm no other lens would have manual focus capabilitity inside the housing but Sony E 16 mm (and 20 mm) is AF and should allow Autofocus via camera controls. However Meikon uses a different wording for each of these lenses. 16 mm: NO MANUAL FOCUS ; 20 mm: AUTOFOCUS ONLY. That's what breaks my head.
And in both cases, when combined with a converter the remark is NO MANUAL FOCUS

Do you have any experience or have heard about the use of the Sony 16mm (or 20mm) combined with a Fisheye or Ultra wide Converter in the 4" dome?
I am not really clear about what to expect if I buy this lens.

regards

 

[Barmaglot]

Do you have any experience or have heard about the use of the Sony 16mm (or 20mm) combined with a Fisheye or Ultra wide Converter in the 4" dome?

Sergei Markov has posted some samples using A7 II (in APS-C crop mode) + SEL16F28 + VCL-ECF with Meikon housing and 4" dome here, but they are heavily downscaled. The 16mm lens is notoriously soft in the corners, but I don't have one to provide a personal impression. To be fair, the corners on SEL1018 behind a 6" dome aren't all that hot either - I got an 8" dome on Meikon's last Black Friday sale; will try it out on my next trip and compare with the 6" one. Still, the 180 degree field of view on a fisheye lens is very wide - too wide in many situations, where you have a skittish subject that doesn't appreciate being poked with a camera dome. Conversely, the 10-18mm zoom range is quite useful - while 10mm rectilinear is not as wide as a fisheye, the longer end is useful far more frequently than the ability to go wider; in fact, I would've loved to have a 10-24mm zoom range rather than 10-18mm, but it is what it is. It is similar for full-frame shooters, where the 16-35mm lens is considered more useful than 12-24mm (FOV of 10-18mm on APS-C is equivalent to 15-27mm on full-frame).

 

[Hector1959]

Good references.
One friend of mine love wider and wider and has tried to influence me over fisheye for WA (as for smaller and smaller in macro). I'll have to think about it.
I remember to have read one post of yours where you said that fisheye shots were not everyday's and that had left me thinking.
Thans you again.
Regards