Jump to content
Digizz

L&M Bluefin 80 Deg Lens?

Recommended Posts

The fantastically helpful guys at Fish Eye Productions (FEP - UK) have very kindly lent me a standard 80 deg lens to try out with my new Bluefin. I already have the UWA lens but wanted to see if I should get the 80 as well. I've just fitted it and will be diving in a pool with it today and tomorrow but had some initial questions:

 

  1. I was surprised that without macro flip, this lens still doesn't allow full zoom through - only going to around 75%, the same as the UWA - is this what you find too?
  2. With the flat port macro flip down, I do get 100% zoom through - although not checked the quality of the recorded images yet under water. Anyone use the standard macro with the 80 - what are the results and do you see much distortion etc (I guess there's a reason there's a specific 80 deg macro)?
  3. I don't have the new macro flip for the 80 to try - is it worth it?
  4. My concern with the 80 is that on zooming, you have to be very careful not to exceed the 75% zoom otherwise this would potentially ruin the shot as it goes out of focus. Anyone find that a problem or use the macro flip for this reason?
  5. The lens I'm borrowing is second hand and has a slight film like patchy coating on the outer glass surface. I tried removing it with Isopropol Alchohol but it didn't budge. Is this common with lenses - maybe it hasn't been kept clean - or is it something else? Will this affect the images?

Thanks,

 

 

 

Paul.

Edited by Digizz

Share this post


Link to post
Share on other sites
I was surprised that without macro flip, this lens still doesn't allow full zoom through - only going to around 75%, the same as the UWA - is this what you find too?

Yes. I have the Z1 which offers a numbered readout of the zoom 0-99 and I get to about 70 and then no more.

With the flat port macro flip down, I do get 100% zoom through - although not checked the quality of the recorded images yet under water. Anyone use the standard macro with the 80 - what are the results and do you see much distortion etc (I guess there's a reason there's a specific 80 deg macro)?

I was told this wouldn't work so I haven't tried it. I would expect distortion but by all means do some testing and let us know.

I don't have the new macro flip for the 80 to try - is it worth it?

Absolutely. Mine is in and out all the time when I'm close in on the reef. Say I've got something like shrimps which go out of focus before filling the screen enough, I just flip in the lens and I can get them much larger. Not as large as with flat port + flip macro of course.

My concern with the 80 is that on zooming, you have to be very careful not to exceed the 75% zoom otherwise this would potentially ruin the shot as it goes out of focus. Anyone find that a problem or use the macro flip for this reason?

I tend not to do much dynamic zooming during my shots. Not generally my style but also I find the slowest zoom speed to be too fast. So I generally zoom in until it goes out of focus. Then out until it's sharp, and get my tight shot. If it's not big enough in the frame then I flip the macro lens in and zoom in more. Then often I get my wide shot after and swap them in post (wide first). I don't think the FX1 has the zoom numbering so I guess it would be more difficult to judge when to stop zooming if you're into zooming during the shot.

The lens I'm borrowing is second hand and has a slight film like patchy coating on the outer glass surface. I tried removing it with Isopropol Alchohol but it didn't budge. Is this common with lenses - maybe it hasn't been kept clean - or is it something else? Will this affect the images?

This may well be water marking. Try a magic eraser (one of those white ones) on it.

 

Nick

Share this post


Link to post
Share on other sites

Paul,

Great questions and Nick, great feedback. Let me see if i can contribute any input in addion to Nick:

 

1. 80 zoom thorugh

-Yes...i get about 70 zoom through

 

2. Flip macro + flat port quality

-I get no observable distortion using the flat port and flip macro. I must stay the images it produces are stunningly crisp.

-I have tried the std flip with the 80. No good...not as much an issue of distortion as focus. Dif focal distance so you lose focus almost immediately

 

3. Is 80 flip worth it?

-Depends on how serious you are about your macro. I only use mine occasionally when i stumble on a macro subject i just had to shoot. For the most part when i film macro, i go for the best i can get (flat port and flip). Just need to decide your style. It is nice for zooming the eye of the octopus once you have finished he mating sequence:)

 

4. Issues with Zooming?

-What Nick said. I personally find dynamic zooming distracting. Generally I zoom in until focus is lost then back out to focus, hit record and get my close up. I sometimes follow this with a zoom out from the tight shot to wide. B/C there are no issues with full wide, i never have a focus issue during record. as a rule of thumb, i zoom with my fins for any wide/dynamic shots. I am a resolution junky and love m DOF. Zooming in a wide shots tends to degredate both.

 

5. Film on Lens

-This is watermarks for water droplets drying on the lens. This issue has been experienced by others as well. Make sure you fresh rinse and dry the lens immediately after leaving the water. B/c the lens is not coated, the risk of scratching is pretty low if you have a clean towel. Periodically use rubbing alcholol and the magic dry erase to clean it. That being said, the film you see can become permanent. I have this on my lens that I have been using for a year. You will not observe it in most shots. You will observe it however, when shooting direcly (or close angles) into the sun in shallow conditions. However, this is the most likely scenario to reveal imperfections in any lens. A bigger issue with direct shots into the sun is refraction that will reveal the reflection of actual z1/fx1 lens and barrel in your shot (they are reflecting on the interior surface of your lens.

 

hope this helps you out.

 

shawn

Share this post


Link to post
Share on other sites

Good feedback too Shawn. A couple of things I picked up on...

I am a resolution junky and love m DOF. Zooming in a wide shots tends to degredate both.

Not sure why you're relating resolution and DOF :lol: For me it's the opposite, I often want less depth of field. i.e. A blurry background or foreground for a more dramatic, "film-like" look and to concentrate the eye. Topside a good way to do this is to get further away from the subject and to zoom in. But obviously underwater that technique has the disadvantage of more milky water between cam and subject.

 

That being said, the film you see can become permanent. I have this on my lens that I have been using for a year.

This is worrying. What do L&M say about it? Is there nothing that can shift it? I have been trying to dry my lenses with a tea towel soon after washing them but have forgotten once or twice on the boat. So far I see no evidence of this watermarking but maybe this only happens with certain types of water?

 

Nick

Share this post


Link to post
Share on other sites

Thanks for the replies guys - hopefully will help others too eventually :lol:

 

 

 

I dived in the pool yesterday with the 80 (although only for 10 minutes) - was the wow of the other divers! They all wanted a play :)

 

 

 

Nick - I do have the Z1, so was relating my zoom through numbers to the zoom percentage - shame the camera doesn't have a 'shuttle shot' function that allows a max zoom level to be set - mind you, this only appears on my high end lenses that cost £10,000 or more!!!

 

 

 

TBH, I don't zoom very much during a take when filming professionally above water - maybe my techniques will be similar u/w? Difficult to know yet as I'm very early on in getting used to the camera/housing (filming HD is also new as my others cameras are all SD. HD is a very different beast).

 

 

 

Shawn - I printed out your list of balast examples but forgot to take it yesterday - will try today! I found in the fresh water pool that the 80 with two weights and battery pods (full) was too negative - so this will be less so in salt water of course - have you pool dived with that combo? I presume your examples were salt water based?

 

 

 

Thanks, Paul.

Share this post


Link to post
Share on other sites

Paul assuing you're using the 80 lens and the full length Sunray battery pods I would try just one weight halfway along the right rail. Even that is a little negative in salt water so will be too negative, if anything, in fresh water.

Share this post


Link to post
Share on other sites

Yeah guys. My balast is with shorter battery pods. Will need to adjust for full length. That being said, salt water makes a big difference and i find even different locations in the world (salinity variances) makes a difference.

 

I for one like my housing slightly (or a bit more) negative for increased stability...especially in surge and current.

 

Nick, spot on regarding why i relate the two. I find that blurry underwater and more milly look can come across as poor filming and not style. In clear water and good contrast...i like it. Unfortunately, that is hard to find in most places.

 

L&M is aware of the lens spotting. There really isn't anything you can do about it...so take care of it. However, my L&M uncoated lens produces nice clean images after a year of intensive use vs the degredation i experienced with my prior housings coated lens in one month. Trade-offs:)

Share this post


Link to post
Share on other sites

What actually is the lens spotting? Some sort of calcium or salt deposit or...?

 

I wonder if a regular application of Rain-off or similar might help resist it (as well as help droplets run off at the surface) :)

Share this post


Link to post
Share on other sites

We have heaps of calcium in the fresh water here so it's important to dry the ports and stuff after whashing or you will end up with real bad calcium spots.

 

On my old Hi8 housings there is real bad calcium spots that nothing will take off. We even tried Petrol & acid tone, but to this day it's still there. :)

 

The water is so bad here that we don't even wash out the outboard with it, you should see inside our kettle...

 

Dry those lenses after a fresh water dunk is the best.

Share this post


Link to post
Share on other sites
We have heaps of calcium in the fresh water here so it's important to dry the ports and stuff after whashing or you will end up with real bad calcium spots.

 

On my old Hi8 housings there is real bad calcium spots that nothing will take off. We even tried Petrol & acid tone, but to this day it's still there. :)

 

The water is so bad here that we don't even wash out the outboard with it, you should see inside our kettle...

 

Dry those lenses after a fresh water dunk is the best.

 

 

 

An acid such as plain old vinegar will dissolve calium carbonate - did you try soaking in vinegar? or maybe it's a different form of calcium or has actually bonded with the glass :)

Share this post


Link to post
Share on other sites

Ok...i'll give that a try...fingers crossed.

Share this post


Link to post
Share on other sites

Sponsors

Advertisements



×
×
  • Create New...