23 replies to this topic

[james]

Check it out - an Aquatica housing for the Mamiya RZ-67:

http://cgi.ebay.com/...4&category=4703

Cheers
James

[craig]

I heard this rig weighs around 50 pounds ready to dive! Could that be possible? Check out that viewfinder!

[herbko]

What's a good tripod to go with this?

[tshepherd]

Uh, I don't think my wife would let me take all that luggage on one trip. Imagine that, one camera, no strobes, and you're already at or over your checked luggage maximum....

[craig]

Uh, I don't think my wife would let me take all that luggage on one trip. Imagine that, one camera, no strobes, and you're already at or over your checked luggage maximum....

You would look so good, though. Besides, what's the overweight charge, 25-50 bucks each way? A small price to pay for prestige!

[Alex_Mustard]

Medium format is certainly the hefty way to take pictures underwater. My Hasselblad rig weighs >10kg and for that reason gets left at home more than I'd like. Also depth of field issues mean that MF is not actually as good a tool for UW as 35mm or digi. IMO! But about a month ago I gave at talk at BSoUP showing my medium format shots and when the shots are up there on the screen looking fab - all the effort really seems worth it.
Alex
Page about my hasselblad

[james]

What, that puny blue thing?

Cheers
James

[Cybergoldfish]

Saw that - Cost effective yeah!

[tshepherd]

A small price to pay for prestige!

Just think of all the prestige I could get from that, it's got 5 Pelican cases!!

[Cybergoldfish]

You would look so good, though. Besides, what's the overweight charge, 25-50 bucks each way? A small price to pay for prestige!

In the real world it is $30.00 per Kilo!

[craig]

OK, a large price to pay for prestige. But the looks you will get...priceless!

Now, if you could get that thing to do 2:1 (35mm equiv), just think of the fun you'd have. Don't forget the really big strobes!

[Cybergoldfish]

OK, a large price to pay for prestige. But the looks you will get...priceless!

I get my thrills driving an X5 BMW

[yahsemtough]

Just one Bob?

[james]

Ya, I thought it got stolen???

J

[herbko]

OK, a large price to pay for prestige. But the looks you will get...priceless!

Now, if you could get that thing to do 2:1 (35mm equiv), just think of the fun you'd have. Don't forget the really big strobes!

I don't think the strobe's the hard part, you should be shooting the same F-stop as 35mm or you 'll loose resolution due to diffraction. The DOF will be microscopic. You're magnifying the subject 4x !

[craig]

Some of the lenses for this camera go beyond f/32. The amount of diffraction you can tolerate is proportional to the circle of confusion you accept. I don't know what that is for this camera but it's lenses go at least to f/45.

Let's say I had a subject 35mm wide that I wanted to fill the frame with. For 6x7 that would be 2:1 and for 35mm that would be 1:1. Assuming both cameras are shot at f/32, bellows effect makes the effective f-stop f/64 for 35mm and f/96 for 6x7. In reality, you may shoot the 6x7 at f/45 which makes the problem even worse (f/135). If you are using ISO 50 film you would need big strobes or narrow beams for 6x7 and that's only for 1:1 equivalent. A pair of 400's might do it.

I suspect the point is moot since achieving magnification like that is probably out of the realm of the camera. I'd be happy to hear if people do that, though, and how.

[herbko]

Some of the lenses for this camera go beyond f/32.  The amount of diffraction you can tolerate is proportional to the circle of confusion you accept.  I don't know what that is for this camera but it's lenses go at least to f/45.

Let's say I had a subject 35mm wide that I wanted to fill the frame with.  For 6x7 that would be 2:1 and for 35mm that would be 1:1.  Assuming both cameras are shot at f/32, bellows effect makes the effective f-stop f/64 for 35mm and f/96 for 6x7.  In reality, you may shoot the 6x7 at f/45 which makes the problem even worse (f/135).  If you are using ISO 50 film you would need big strobes or narrow beams for 6x7 and that's only for 1:1 equivalent.  A pair of 400's might do it.

I suspect the point is moot since achieving magnification like that is probably out of the realm of the camera.  I'd be happy to hear if people do that, though, and how.

You could. But what have you gained by going to a piece of film that's twice the width and at the same time double the blurring due to diffraction? For all your troubles, you end up with the same amounts of detail.

To be specific, if you were to blow up a pygmy seahourse to 1m in length. You get about the same thing at f/32 for a 35mm film and f/64 for a 70mm film.

[Cybergoldfish]

Ya, I thought it got stolen???

J

We have a spare!

[craig]

You could. But what have you gained by going to a piece of film that's twice the width and at the same time double the blurring due to diffraction? For all your troubles, you end up with the same amounts of detail.

To be specific, if you were to blow up a pygmy seahourse to 1m in length. You get about the same thing at f/32 for a 35mm film and f/64 for a 70mm film.

If the only reason for larger formats is larger viewing sizes then you're right. But if you shot 35mm at f/22 and 70mm at f/45 you have 4 times the surface area of film so your grain would be proportionately reduced and you would achieve 50% greater depth of field at a 35mm 1:1. Larger formats are capable of greater DOF but only if you choose equivalent apertures and accept that the total number of lines resolved will be the same. If you insist on resolving more detail then DOF will suffer. I suspect the lens designers put f/45 on the lenses for a reason.

If you shot f/32 vs. f/45 on the same example you'd have roughly the same DOF and superior overall resolution for the 70mm.

[Marc Furth]

That sounds lite compared to my DXC 125 video housing I made, 80 lbs. not including the camera and lights.
I once paid full fare on Chalks Airline to Bimini just for the housing.

Marc