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Ikelite 8" Dome

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:blink:

 

I find it funny that even Ike will admit that they find no evidence that you will get better performance behind an 8" dome over the 6" even after they tested it, but because people for some reason believe different, they are offering an 8" for an obvious mark up.

 

Hey, I already admited that I'm intested in this new dome. But at least I'm honest about why I want it. A: It will house 2 of my lenses B: It looks cool C: over unders

 

Has nothing to do with which will provide a better image.

 

Quote from Ikelite:

"Advantage of the larger radius dome port is over/under photos. We see no proof it provides sharper images with very wide angle lenses as some people contend, but we have had enough requests to warrant making it available."

 

I'd love to see someone prove this otherwise.

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You want examples of me cleaning my domes? 

 

LOL... I agree with Kasey's comments about dome maintenence. I've used three Sea & Sea NX Fisheye Dome Ports in the past 2 years, all of them replaced when the inside was scratched. None of these scratches would have occured if I was using a glass dome... I'm really curious to know how many ports someone like Jim Watt goes through in a year.

 

The diopter attacking port issues you speak about were caused by an incorrect recomendation on a port chart that has been revised. There is a certain value judgement that occurs. In this case, Ike was dealing wiht an 18-55mm lens that costs less than $100, making a perfect port placement pretty much irrelevant due its narrow field of view and less than L optics.

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I understand the logic, but as an observer it makes a statement to the precision of Ike's port system. If an extension system were in use even a $100 lens would justify an extension. Perhaps it is unfair to judge the system by a single mismatch. It was so obviously incorrect to me, and frustrating trying to explain to a neophyte that what Ike recommended could not be correct! Aside from this I have very limited experience with the Ike system beyond seeing pictures on this and other websites.

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Julian, you are correct, the center of the radius of curvature of the #5503.15 port is not at the entrance pupil of the lens as I had stated earlier. Nor can it be for any port I can imagine.

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Hi Folks,

 

I have pool tested the 8" dome with the Canon 20D and 10-22mm lens. I have comparison photos of a test "chart" taken with the standard Ikelite port and the 8" port. I'll post these in a review soon.

 

Cheers

James

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Julian, you are correct,  the center of the radius of curvature of the #5503.15 port is not at the entrance pupil of the lens as I had stated earlier. Nor can it be for any port I can imagine.

 

It is possible with the proper neck length/extension on the port, and some ports are set up just this way; simplified discussion available here.

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I find myself constantly repairing scratches in plastic domes and they're always the kind that are unlikely to ever occur in a glass dome. It drives me crazy. It's true that plastic can be repaired in a way that glass cannot, it's just a shame that you'll always need to. I'm looking forward to not having to do that with my glass domes. Wish I could convert my friends as well.

 

Glass also passes more light than plastic. Whether it's "scientifically provable" that it makes a difference to your eye is beside the point. It's certainly "scientifically provable" to the measurement machine. I'd rather not have a bevy of scratches softening my images so I like glass.

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I have pool tested the 8" dome with the Canon 20D and 10-22mm lens.  I have comparison photos of a test "chart" taken with the standard Ikelite port and the 8" port.  I'll post these in a review soon.

Can't wait to see that James - I'm sure it will be very informative.

 

Any sneek previews? :blink:

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Glass also passes more light than plastic.  Whether it's "scientifically provable" that it makes a difference to your eye is beside the point.  It's certainly "scientifically provable" to the measurement machine.

This sounds oddly familiar to the claims on PC Gaming forums that 129 frames per second in a video card is way better than 120 fps.

 

How often are you guys actually getting scratches on your ports. I just got home from work and checked all my ports for scratches, and found none. I didn't think I had any, but by the tone of this thread, I thought for certain I would have some.

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<snip>How often are you guys actually getting scratches on your ports.  I just got home from work and checked all my ports for scratches, and found none.  I didn't think I had any, but by the tone of this thread, I thought for certain I would have some.

I'd think a lot depends on your attitude. I don't pamper my camera gear by any means; they are tools, not objects d' art. A good description for all my bodies and lenses would be "press corps ugly".

 

Still, I've always treated optical surfaces with respect, and even my oldest 15+ year old Aquatica dome is without blems. This is after a pretty hard life, and it's not been resurfaced.

 

I've noticed I am a minority in that I get into the water with the dome beanie in place, and only take it off when at the worksite, then, replace the beanie before getting out of the water. I believe there is more damage potential on the boat than in the water.

 

To the point, I've actually only replaced a dome once. This was for a gouge that would have totaled a glass dome just as easily.

 

All the best, James

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I get scratches on plastic domes all the time and so do my friends. I've had to fix plenty of them, not just mine. Perhaps you should look closer.

 

As to the difference in the amount of light passed and whether it is relevant, look it up. Perhaps you won't mind if your lens elements are made of plastic as well.

 

I find it curious that anyone would concern themselves with the optical quality of anything yet dismiss the optical quality of other elements in the system. Perhaps you don't care about the performance of your camera or lens either. I do and I care about the performance of the dome and the material it's made out of. It makes no sense not to.

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Kasey, please. Problem in your post #28 had nothing to do with the "precision of Ike's port system." This was simply addition of a plus diopter that was thicker than anticipated.

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Our ports are acrylic, not polycarbonate for the confused experts. I polled several National Geo photographers about material choice and was surprised to find glass is not always preferred. One comment was "I'm not a big fan of glass domes

since they are heavy and get streaking that never disappears." We chose to attach Aquatica domes because of their stellar reputation. What would you pay for glass. I have a source, but believe complete dome would be at least six hundred dollars.

 

E-mail me at <ike@ikelite.com> if you want to avoid cluttering the forum..............

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Our ports are acrylic, not polycarbonate
I was already wondering if PC is some english short term for "Acrylglas" (what it's called in german). So PC=polycarbonat.

 

Julian, you are correct,  the center of the radius of curvature of the #5503.15 port is not at the entrance pupil of the lens as I had stated earlier.

Peter,

 

OK, thanks a lot for the info. I was already a bit confused as I've never used an Ikelite dome with a fisheye but reffered to some board data.

 

Nor can it be for any port I can imagine.

Yes, there are some 180° domes. I've an older Seacam fisheye dome and the newer one is also a true hemnisphere.

9.jpg

 

But smaller than the SuperDome which is basically for wideangles but also used for fisheyes often. I think Nexus offers a 180° dome but more focused on split level work than taking it underwater:

nexfep.jpg

 

But as stated before most manufactures put them behind a smaller curvature because they still often perform better than wideangles behind it.

 

Julian

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You can get away with crop-sensor cameras, full-frame WA lenses, and diopters. But I find that slapping a diopter on a wide angle lens connected to a full-frame camera is disaster. So I shoot with a big dome and do not use a diopter.

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I was already wondering if PC is some english short term for "Acrylglas" (what it's called in german). So PC=polycarbonat.

 

Marjo used the term PC and it stuck for the duration of the discussion. I don't pretend to be an expert in materials engineering, I just prefer glass to acrylic after maintaining both.

 

In regards to light transmission - hold your glass dome up to the sky and look thru, then do the same with an acrylic. It doesn't take a light meter to see the difference! Looks like 1/3 stop or more. Not so significant for digital, but shooting velvia I'll take all the light I can get!

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yes, I've picked up PC as well assuming it's the material Ikelite Dome's are made of.

 

agreed, yes, I prefer the contrast and clearness of glass as well. Even with digital :-) I consider this as image quality as well and the theoretical refraction index advantage of acrylic doesn't outperform the other items.

 

Julian

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Hi Julian,

 

I you want to buy Ikelite stuff import it directly from the states. I did it and saved big times without any hazzles. What Werner Voelker and ProSub are doing is absolutly ripoff! Both need to be avoided by any means!!!

 

I recommend Ryan or bhphoto.

 

Best regards

 

Chris

 

But the Ikelite 200% German price philosophy and the absence of a bigger dome for fisheye (split) work weakened my interest and I kept using my film camera with the Seacam port system a little longer.

 

Julian

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If I house up my camera and take it out in the back yard.

 

Set the exposure in manual mode and take 2 pictures.

 

One with a Acrylic port, and one with NO port attached and set to the same exposure, how many people here claim they will be able to take the pepsi challenge?

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If I house up my camera and take it out in the back yard.

 

Set the exposure in manual mode and take 2 pictures.

 

One with a Acrylic port, and one with NO port attached and set to the same exposure, how many people here claim they will be able to take the pepsi challenge?

 

Great Idea!!! Be sure to use a pro quality lens or prime!

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Christian,

 

thanks for the information. If I would have chosen Ikelite I would have tried B&H.

I guess warranty is covered when you send it in to the USA? Ike? Could you please confirm?

 

ProSub is ridiculous. Nothing in stock, could give me absolutely no product information. I asked how I could confirm that an intended setup works. They said they don’t know and I have to try it out. But if the combination doesn’t work/fit, they told me right away “We won’t take back any of the accessories in general, you have to keep it even if it doesn’t workâ€.

 

In my opinion they do nothing more than moving closed shipping boxes. But they increase the price to over 200%. The few times I had called them I always had the feeling of disturbing someone. And an 10D housing only price of 2500 US Dollars was not my taste.

 

A German dealer told me that ProSub has had some kind of exclusive contract for Ikelite distribution in Germany – but the contract would end very soon. I don’t know if the rip-off will continue?

 

Julian

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Great Idea!!!  Be sure to use a pro quality lens or prime!

 

one wide open for drop off demonstration please. and another one stopped down to see possible dust/reflections, etc. :blink:

 

Kasey, don't forget someone taking a pic when cleaning your glass. :)

 

Julian

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I understand the logic, but as an observer it makes a statement to the precision of Ike's port system.
??? :blink: ??? You were the one who recommended I go with Ike instead of that other brand... Hopefully you like what you recommend :)

 

Anyhow, I am happy I did go with that recommendation, because I have been very happy with Ike's gear. I have not had problems with scratching, besides the already discussed, in which case Ike shone with his brilliant service, replaced the port and changed the recommendation on their site. I do not think this incident is any reflection on precision of Ikelite gear. I have heard of other brands having problems with xyz. I do not know of how those brands react on complaints besides what I have read on this board in other threads. What i DID learn from this incident was how Ike responds to events, which is promtly, openly, and with outmost concern and diligence.

 

Granted, I only dove with this system about 160 dives (about one year), and the system has only been on one "rough" overseas trip, but my shoredives are not "gentle" either, climbing on rocks and rolling in the surf happens... I have not had problems with foggig or "swirling", and I certainly have no problem with cleaning the port of keeping it clean and clear. The only little thing I would change if I could would be to get a bigger viewfinder, but I wouldn't be ready to pay another 1k for it.

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Ps. Kasey, I'll take a pic of you cleaning your glass this weekend, and thereafter I can take a picture of you cleaning MY Poly...sorry.. Acrylics, and then we can make a scientific study :blink:

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