65 replies to this topic

[ronrosa]

That's good to know Wags. The Gates A1 wide angle lens while expensive at least sounds like it's doing the job pretty well. Apparently it also allows full zoom through which is a big plus.

Most of my dives are warm tropical clear waters, so maybe the low light limitations won't affect me as much as others.

I'm still going to wait until the fall. I can't see Sony letting their lineup stay unchanged.

[Drew]

Wags
A wide angle lens does not increase lux sensitivity. If anything it decreases light going to the sensor. The many elements of glass light has to go through (and thus absorbed) knock off any increased light the bigger surface area of the WA converter. I would delve into optic physics but I've forgotten enough to not try.
What you are seeing is actually the reverse, that the macro lens is absorbing more light than the wide port. Lack of a good coating (glass reflects 8% light back but good coatings only less than 1%). Hence the perceived benefit of a wider port.
The best way to see this is to set the camera in manual fixed shutter speed and aperture in lower light (less than 200lux) , then change lens.
The lux rating of the camera is fixed at whatever it is at because maximum light is at the camera front lens. The perceived increase in light comes from the wider FOV bringing in more subjects with light.
Hope this clears it up before everyone rushes out to buy the biggest and baddest WA converter there is.

Well we do get hit with swell that stirs everthing thing up so it's no problem in getting dirty conditions. We will take them under the Exmouth Navy Pier and test out as well, dark and dirty down there.

I have watched materail shot with the Z1 and A1 in gates housings and you had to really look to see the difference, although it was on a DVD so low quality. The Z1 had the 120 lens on while the A1 had the 110 lens on. It was also shot in blue water so maybe good light getting down there.

Another reason while the A1 might not be as good in low light due to the narrow FOV compared to the Z and FX. Just allot les light getting in their so a good wide angle will help it out heaps.

Here is something...I just dived yesterday on the Navy Pier with the Phenom with the New Macro Dome Port on and shot full wide. It works fine but after a bit I came up and put the 94 degree lens on and went back down. There is a huge difference in image quality/look with the 94 degree lens on, but it's good to know I have a backup port for an emergency.

<{POST_SNAPBACK}>

[DeanB]

Yeah sorry Mr Twist...

I 'have' sold the 950 to a friend, but I still have it at home...Long story

I will check out a comparison as soon as I'm able. Thing is it will make no difference as I've splashed out on the A1 anyway.

Dive safe

DeanB

[ronrosa]

.....Hope this clears it up before everyone rushes out to buy the biggest and baddest WA converter there is.

Hey Dru, that sounds like a good description of the Gates fathoms lens.

I found your post from Dema.



Man that lens is huge.

[Drew]

Ron
I suggest 4 sets of arm curls, 3 sets of incline jerks of 30lbs each for 4 times a week on top of your present regimen.
And it's not that big... but it's quite heavy.

[biminitwist]

No worries DeanB and not to give you the wrong idea I'm not an A1 hater. When its got the right conditions it blows my 900 away. I just want people picking one over the other to hear some of the things I've noted but hadn't heard much about. Given a week with ScubaDru he could probably show me settings to compensate for a lot of what I'm having trouble with (if my head didn't explode from informational capacity overload). Wags, if your playing under the pier try panning from a lighted area to a darker one and watch it grain out. This is much more pronounced below 100 feet. Even with the focal distance set and subjects clear and crisp when it clouds over say you see subjects now appear slightly blurred.... I'm looking forward to hearing your results (and ways to correct). Thanks. John

[ronrosa]

Ron
I suggest 4 sets of arm curls, 3 sets of incline jerks of 30lbs each for 4 times a week on top of your present regimen.
And it's not that big... but it's quite heavy.

<{POST_SNAPBACK}>

Well I already do plenty of 12oz beer curls on a regular basis.

Unless it's a trick camera angle, that thing looks 6" long, 6" in diameter and in desperate need of a buoyancy coller.

[Drew]

Given a week with ScubaDru he could probably show me settings to compensate for a lot of what I'm having trouble with (if my head didn't explode from informational capacity overload).

<{POST_SNAPBACK}>

Errr sorry, I don't help with compensation of anything.

Well I already do plenty of 12oz beer curls on a regular basis. 
Unless it's a trick camera angle, that thing looks 6" long, 6" in diameter and in desperate need of a buoyancy coller.

<{POST_SNAPBACK}>

Ask ShawnH. He played with it for 4 days in a river. Mind you he's a bit of a arm curl guy anyhow.

[ronrosa]

Just heard from Gates that the lens comes with a buoyancy collar/tube.

[shawnh]

I used the medium wide lens in the river. It was heavy but reasonable. The housing with lens however was very negatively bouyant. With the ultra wide (weitwinkel), you will be very negative and very nose heavy. The lens did a nice job for me but i was shooting shallow and over-unders. I would be interested to see how this effects low light. One concern with the length of the lens (vs a nice dome sitting close to the camera sensor) is that at depth i would expect more of a tunnel effect, more chance for vignetting as the iris opens up, an more light fall off). I think others have already experienced this issue.

[NickJ]

So - been editing my 30 yr wedding anniversary trip video from Tuscany. Ah - the romance, the wine, the food, the sun, and oh yes the Sony A1 shots inside churches and restaurants.

I uploaded all 3 hrs of the trip video to my G5 prior to edit and was playing back for review on my wide screen HD TV, skipping from clip to clip through FCP.

The high res stuff outside and in the sun is mind bogglingly beautiful in HD - the detail, the colours - but get inside a building or take some shots in the evening and there it is - flat textures, heavy grain, loss of tone, and muddy colours!

Sorry guys but the low light capabilities of the A1, well ... suck, and that's a critical issue for u/w. I was seduced by the form factor, and not the performance - there weren't a lot of write ups around when I invested....

I am now seriously considering the gym workouts (I'll be lighter of course in the wallet) and going for an FX1 and a tried and tested housing. Only three choices I see really - Gates, Phenom, and LMI. The FX1/Z1 is being used professionally by many commercial shooters now, and I believe the support will be there from Sony for a while to come.

I don't believe there will be field-tested housings available for any of the new cameras for a good while, but we have seen a lot of postings here on the pros and cons of the available brand name housings for the FX1. The vendors themselves have made improvements based on feedback from here and other sources.

I really wish there was a smaller viable alternative, and I won't be carrying any housing in a back pack through any airport, (well anyhow it seems this combo won't fit neatly into a clear plastic zip-lock for carry on!) but these are the conclusions I'm coming to now ....

[MikeVeitch]

Wow NIck.. congrats on 30!

Can i call you dad? hahahaha

[NickJ]

Thanks Mike - the only concession Heather asked for on this particular vacation was 'no diving'! I shouldn't complain as she's dived with me for all those 30 years and never compained once! I must say it was a novelty for me too not geting up at 6am to check camera gear and dive profiles.

BTW - you can call me whatever you want if you go halves with me on a new videocam and housing

[wagsy]

Wags
A wide angle lens does not increase lux sensitivity. If anything it decreases light going to the sensor. The many elements of glass light has to go through (and thus absorbed) knock off any increased light the bigger surface area of the WA converter. I would delve into optic physics but I've forgotten enough to not try.

<{POST_SNAPBACK}>

Drew
Yes I would agree that is does not increase the lux sensitvity but I would of thought if would bring in more light to the sensor as it's has more of a larger footprint of the scene/light comming into it therefore more light hitting the sensor?.

Nick there you are..congrats on 30 years...I'm about to start my day one in November Wonder if I will get to 10,950 days like you guys have

[MikeVeitch]

[pmooney]

Wags,

I know you have mentioned the big day before , I remember the venue - on the beach @ rotto....... what's the date & location of the stag party ??

[NickJ]

Hey Wags, about time you made an honest woman out of that lovely lady. Well done for finally making the leap! (reminds me of that famous speech: Today we stand on the edge of a great precipice; but tomorrow is a great leap forward...!)

You'll find that 10,950 days (is it really that!!?) goes really quickly when you are both happily planning together, working on buying new camera equipment etc ...

[Drew]

Drew
Yes I would agree that is does not increase the lux sensitvity but I would of thought if would bring in more light to the sensor as it's has more of a larger footprint of the scene/light comming into it therefore more light hitting the sensor?.

Actually no. The amount of light increase with the larger glass area is negated by the number of glass elements in a WA lens, all absorbing a % of the incoming light. Furthermore, the size of the CCD is the major limit factor. If the size of the lens were all that mattered then technically the Canon XL series would be king of low light but it's not. A lot of it has to do with pixel density of the sensor, the more pixels per micron, the less sensitive to light the sensor is.

The phenomena of observed increase in light when using a UWA lens is actually the picture have increased brighter objects in the frame vs the built in lens. Thus it seems like the picture is brighter but at best there's no drop off as modern lens makers have coated the glass to reduce reflection.
The best way to demostrate this is to have the camera in full wide and manual. Then set the shutter speed, aperture , gain to a fixed amount exposing correctly of course. Then put on a WA lens and make sure you change the FOV to match the picture without the lens. You should see a darker picture.

PS 30 years is approximately 10957.2 days

[wagsy]

Drew.... that all makes sense with the extra glass taking away the strength of the incoming light to the sensor but lets say.....

A normal 70 degree FOV has a light value of say 70.
You put a wide angle on and zoom in to the same FOV and the light strength value drops to say 50 thats getting to the sensor due to all the extra glass it has to travel through.

You zoom out to new 110 FOV with the wide lens on and your light value goes to 80+ due to the extra light the lens is bringing in now even though you are loosing the stength of the light that getting to the sensor it's still higher than without it.

I just got me TRV900 out and locked it all off and pointed it to a dark area of the room while placing the WA infront of it to compare...it indeed, although only a tiny bit give a slightly brighter image with the WA on.

Next by having a wige angle on it spreads the particles in the water further apart from each other thus allowing more light rays to hit the camera and not get reflected by them.

Thats how my brain is thinking thats all. but it could be all wrong... but I will leave it at that now.....have to pack the car up....

I know I did not count the leap years

Stag party.....have not even got one orgainised yet....

[DeanB]

Hey Nick,

I'm off to Tuscany a week Friday and I'm taking the A1. I'll let you know how I get on. Although I'll be diving (well trained lady) it will be for only one day(well trained man)

Then I'm coming to Singapore ..Lock up your daughters/beer/wallets/housings/ contracts...

If sony brings out upgrades for the A1/Z1 you should not really need to much of a field test as with the 150 / 170 they will be, well, just better....I'd wait a while longer.

Dive safe

DeanB

P.s I'm off down to 35metres with the a1 in a quarry with no lights..hmm ? I wonder how it will work