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Mark Twain

Member Since 06 Dec 2013
Offline Last Active Today, 02:22 PM

Posts I've Made

In Topic: Macro with the A7R II & Sony FE 90mm macro

Yesterday, 11:53 AM

Hi phil,


could you provide more information about how you took the pictures? Aperture and method of focusing (af/mf and continuous af or single shot?)? The lens seems to be tack sharp, although in some pictures focus seems a bit misplaced to me (fore example in the first picture the focus is slightly before the eye).


You mentioned the availability of a fisheye lens. As there is already the SEL057FEC which converts the FE 28/2 into a fisheye lens, have you ever considered using this combination (assuming that a port is available)? I highly doubt that there will be a native (in the sense that it is not an adpater solution) any time soon as the SEL057FEC is available.



In Topic: Sony a65 Mod with Sigma 10-20mm f/3.5 EX DC HSM LENS

27 October 2015 - 04:17 AM

Could you please post a picture of how you modified the lens?


Interesting work, I considered buying a rectilinear ultra-wideangle lens once but ended up buying the Sigma 10/2.8 diagonal fisheye.

In Topic: Diving in Croatia

27 September 2015 - 02:22 AM

Thank you!


Unfortunately the max sync speed of the A65 is 1/160 - a pure software limitation, as its big brother (the A77) which has the same sensor and processor is capable of doing 1/250. I think the key to better sharpness is more stability.


As you said it is nowhere near the Caribbean or Red Sea or many other spots, but when you live in Central Europe it is easy to get there by car for three or four days and gives you some nice diving. I've been at Trogir Diving Center and most diving spots are whin this region.

In Topic: Diving in Croatia

24 September 2015 - 09:44 AM

Focus could be sharper on all three but especially the purple flabellina.  If you are using autofocus, try switching to a single focus point as small as possible. Aiming to get the rhinopores in focus is often a goal (though your images work regardless and would be worse if you followed that advice).  


What camera / lens are you using, with what settings?


Thanks :)


#1: 1/60, F7.1, ISO 500

#2: 1/160, F11, ISO 100

#3: 1/160, F20, ISO 400

#4: 1/160, F16, ISO 400

#5: 1/160, F22, ISO 100

#6: 1/160, F11, ISO 100

#7: 1/160, F8, ISO 100

#8: 1/160, F11, ISO 100


I think most of the blur comes from shake. Most of my macros of the nudibranches were not useable at all because I could not find anything sharp - which is then caused by shake imho. Furthermore I had troubles because of very negative buoyancy so I'm thinking about getting some floating elements for my arms or macro port.


The wideangles were taken with a Sigma 10/2.8 fisheye and the macros with a Tamron 60/2.8 (which is a really sharp lens) mounted on a Sony A65 inside an Ikelite housing.


As I find it easier to pre-focus manually and then move the housing to focus on my desired object when doing macro I am not using auto-focus (af also hunts a lot when doing macros near 1:1 and there is no focus limiter).


But I'm not 100% sure why so many of the nudis are not sharp. I think it is because of camera shake or wrong focus or a combination of both. Sharpness should be reasonable good even at F22.

In Topic: Any experience with the Sony A72 or A7r2?

15 September 2015 - 02:16 AM

As I own a Sony A7 but do not use it for underwater (I have already invested in a Sony A65 inside an Ikelite housing and can't afford switching in the coming years I'm afraid) I am following information about lens/port availability and general functionality regarding underwater usage very frequent.


I was always quite happy with battery life when using my A7. I noticed that when using the 16-35/4 it drained faster due to IS; when using old Minolta MD/MC lenses battery life was very good, even compared to A-mount cameras which have a larger battery. So I think using a full frame E-mount camera with sensor stabilization and optical stabilizer (e.g. Sony A7ii or A7Rii with 16-35/4) will drain your battery very fast. This means that you have to change your battery after every dive which is always a very unpleasant thing to do (at least for me) and increases the risk of flooding your housing.


I hope Sony will improve the battery life by either reducing energy consumption or providing bigger batteries (which will increase weight) or same-sized batteries with increased mAh.


But I noticed on the images of the first post in this thread that there seems to be some space left beside the camera body inside the housing. So I am wondering if it would be possible to use a battery dummy which is connected to an external battery? This requires an external battery which fits in the housing (and provides more power than a standard battery obviously) and the possibility to run a cable from the battery slot to the external battery.