Jump to content


divegypsy

Member Since 07 Sep 2003
Offline Last Active Yesterday, 04:24 PM
*****

#385196 Nikon 8-15mm in the house!

Posted by divegypsy on 20 June 2017 - 04:10 PM

I saw exactly the same vignetting, caused by the lens shade, when I shot topside pictures.  More extreme vignetting with the camera set to the full FX picture and less when I had my D800 set to the DX crop mode.  If you have an FX camera, like the D800 or D810, you can get the same picture area as Adam did by simply setting the camera to the DX mode.  

 

If you use the D800 or D810 in the DX mode you have a camera that shoots images very similar to the D500. I think it is about 16 Megapixels and has auto-focus spots covering nearly the whole image area. What the D500 offers is faster and possibly more accurate auto-focus, a faster frame rate which is of little use if you are shooting with strobes, and the larger image buffer which again is of little use if you need to wait for strobes to recycle. If Nikon's successor to the D810, D820?, appears with the rumored 46 Mp sensor (an upsized D500 sensor) the D500 will offer very little advantage, except size and weight and price, over the D820 when the D820 is used in the DX mode.  And it will offer more than double the Mp in the FX mode for higher image quality.




#385176 Nikon 8-15mm in the house!

Posted by divegypsy on 20 June 2017 - 04:17 AM

I received my Nikon 8-15mm lens about a week ago and have had it in the water once since then.  Because I shoot with a Nikon D800, my interest in this lens is as a close-focusing full frame fisheye lens.  I have very little interest in circular fisheye images.

 

I initially did a few topside shots comparing this lens to my Sigma 15mm f2.8.  My initial impression is that in dim light, the Sigma may pinpoint the focus in the center of the image a little better than does the Nikon lens. Probably due to the fact that the Sigma focuses at f2.8 vs f4.5 on the Nikon lens when set to the 15mm full frame.  But on those same test shots, the sharpness near the edges of the images were consistently better with the Nikon lens.

 

Underwater I have used both the Sigma 15mm and now the Nikon 8-15 behind the Seacam Wideport which has a radius of curvature of about 75mm, meaning that if you had that port as a full hemisphere, the diameter would be about 150mm or about 6 inches. I also own the Seacam 4" fisheye macro port, but pretty much stopped using it because you needed to cut off much of the lens shade on the Sigma 15mm when using this combination and therefore do not have it with me on my current trip.  I feel that cutting back on the Sigma lens shade resulted in too much image degrading flare.

 

With the wideport, I could use the Sigma 15mm with the manufacturer's full shade in place and although I did get slight vignetting at the corners of the image, I feel the image quality was better enough to use the lens this way.  With the Sigma 15mm, I use the wideport directly attached to my Subal housing body.

 

I switched to the Subal housing body for my D800's because I felt Subal gave me a much more complete set of controls to the D800 body functions than did the Seacam housing body and with the help of a good machine shop I was able to modify the port mount on my Subal housings to take my Seacam ports rather than buy a new set of ports.

 

Because the Nikon 8-15mm lens @ 15mm is physically longer than the Sigma 15mm, I am able to shoot the Nikon 8-15mm lens, with its Nikon lens shade mounted, without any vignetting when using the Seacam wideport in combination with a Seacam 20mm extension tube. With a 25mm extension tube, there may be a very slight amount at vignetting, but still far less than with the Sigma 15mm.

 

Below is one of the shots from my only dive so far with the Nikon 8-15mm lens. It shows a pair of small octopuses mating underneath the Edithburgh jetty in South Australia.  The image was shot late in the afternoon at 1/250th at f16 using ISO 3200 on my Nikon D800.

 

_F8C8929.jpg

 

When anyone does tests to determine the nodal point of the 8-15mm lens, or any other lens, they should be aware that the nodal point of the lens lens can change with both the zoom setting and the focus point of the lens.  I found quite large differences when I did a series of tests on Nikon's 24-70mm f2.8 several years ago. Using the manufacturer's given nodal point is also likely to be at least slightly inaccurate for underwater use because the manufacturer's nodal points are given for lenses focused at infinity rather than at the close distances the lens is likely to focus at when used behind a dome port. 




#367402 Free Diving at Kri Eco in Raja Ampat

Posted by divegypsy on 23 November 2015 - 04:12 PM

Because of a medical problem, an eye infection, I have decided to leave the Kri Eco Resort in Raja Ampat two weeks early.  KriEco has a "no refunds" policy so they will not refund any of the money I paid for these days.  But they have no rule that says I cannot GIVE my remaining two weeks to someone else.  Those days run from 25 November to 8 December with departure on 9 December.  The dates are not changeable.  You will have a single room and the unlimited diving package which includes all diving except the more distant destinations.  

 
You will have to buy your own air ticket to Sorong from where ever you are.  And may have to pay for your boat transfers to and from Kri Eco. I think their normal transfer days from Sorong are on Wednesday and Sunday mornings. If you can make it to Sorong by tomorrow morning, Wednesday, 25 November, you would have two full weeks at Kri Eco.  If you make it there for the Sunday, 29 December transfer you would have ten days.
 
The daily rate for my stay was about €250 per day and I would like to see someone get some benefit from this.
 
I will have to supply Kri Eco with the name and transfer date of whoever takes my place, so please email me to let me know if you are interested and on what schedule you might make it to Sorong.  My email address is fbavendam(at)hotmail(dot)com.
 
Fred 



#367401 Use my days at Kri Eco in Raja Ampat

Posted by divegypsy on 23 November 2015 - 04:07 PM

Because of a medical problem, an eye infection, I have decided to leave the Kri Eco Resort in Raja Ampat two weeks early.  KriEco has a "no refunds" policy so they will not refund any of the money I paid for these days.  But there is no rule that says I cannot GIVE my remaining two weeks to someone else.  Those days run from 25 November to 8 December with departure on 9 December.  The dates are not changeable.  You will have a single room and the unlimited diving package which includes all diving except the more distant destinations.  

 

You will have to buy your own air ticket to Sorong from where ever you are.  And may have to pay for your boat transfers to and from Kri Eco. I think their normal transfer days from Sorong are on Wednesday and Sunday mornings. If you can make it to Sorong by tomorrow morning, 25 November, you would have two full weeks at Kri Eco.  If you make it there for the Sunday, 29 December transfer you would have ten days.

 

The daily rate for my stay was about €250 per day and I would like to see someone get some benefit from this.

 

I will have to supply Kri Eco with the name and transfer date of whoever takes my place, so please email me to let me know if you are interested and on what schedule  you might make it to Sorong.  My email address is fbavendam@hotmail.com.

 

Fred




#365908 Nikon AF Micro-Nikkor 200mm f/4 D IF-ED Lens

Posted by divegypsy on 05 October 2015 - 04:12 PM

Tom.  If you come through Florida on your way to the Caribbean and I'm home, I'd be happy to let you try my 200mm Micro-nikkor in a pool to see if you might like it enough to buy one.  To me, worrying about resale possibility or resale value is far less important than whether a lens will allow you to get pictures that you couldn't have gotten before and whether those images will please you.  I would also think that since anyone who shoots underwater would need to remove the tripod collar, WetPixel would provide you with numerous potential resale customers if you did decide to sell it.

 

Elmer.  Yes, technically a fixed focal length macro lens, like a 60mm or 105mm Micro-nikkor, should be sharper than the 70-180mm.  But many pictures that I've shot with the 70-180mm have been published in magazines like National Geographic, Smithsonian and National Wildlife. And I've made numerous prints up to 16" x 24" and larger that look quite good shot that were taken with the 70-180. Even Thom Hogan rates the 70-180mm as a top quality Nikon lens. Are you using any zooms underwater? Wouldn't you be happier with fixed focal length lenses instead of those zooms?

 

What are you actually doing with your pictures that requires the small technical difference that you see? Is that difference something you only see when you hunt for it on your monitor at 100% or 200% magnification?  Will you be able to see that difference in the waters of the Rhine this fall?  

 

I feel the versatility you gain with the 70-180's 2.5:1 zoom ratio, especially with respect to the shots you don't miss being able to take because whichever fixed focal macro lens you happen to have on the camera for that dive isn't the right lens for a particular subject, far outweighs any minor technical differences between the lenses. I'd rather get a slightly less technically perfect shot than no shot at all.

 

If you haven't already sold your 70-180mm, I have several friends who might be interested in buying it.

 

Fred




#347104 Nauticam 45 viewfinder wobble?

Posted by divegypsy on 01 May 2014 - 05:55 AM

My Nauticam viewfinder also "wobble" slightly when the viewfinders are on the housing above the water.  But when underwater the water pressure, and also the negative internal pressure of my vacuum seal leak detector, seem to hold the viewfinder in place better.  Nauticam uses an o-ring to hold the viewfinder in the housing.  And has two o-rings on the viewfinder "tube".  I believe it is these o-rings that are the cause of the viewfinder wobble.  I've been down to depths of about 200' repeatedly with the Nauticam viewfinder on my Subal ND800, via an adapter, and never had a drop of water get in the housing.

 

Fred




#343079 Vacuum Leak Test Update

Posted by divegypsy on 09 February 2014 - 02:03 AM

If the conditions are very humid and you think you might have condensation problems in your housing, all you have to do is "flush" out the housing with air from your scuba tank just before you close it.  Hold the two housing halves almost together and then blow air into the housing with an air blower that attaches to you LP hose.  Then close the housing quickly and use your vacuum device.

 

Fred




#339106 Nikon AF Micro-Nikkor 200mm f/4 D IF-ED Lens

Posted by divegypsy on 06 November 2013 - 01:49 PM

Used alone, the 200mm Micro-nikkor focuses down to only 1:1, the same as most other true macro lenses offered by Nikon, Canon, Sigma, and other lens manufacturers.  But compared to a Nikon 105mm, the 200mm would require almost twice the working distance, the water between the front of the housing port and the subject.  And too often this extra water distance would result in a less sharp image.  The advantage of using this lens with T6 close-up lens is that the water distance is reduced to a workable 8-18" while the maximum magnification is increased to 1.8x life-size, a very significant increase over the1.0x of the lens alone.  And does this while maintaining a maximum aperture of about f4 to f5.3 for focusing accuracy and viewfinder brightness.

 

Fred




#335692 TTL Anonymous

Posted by divegypsy on 12 August 2013 - 12:19 AM

So sorry Ted, my shooting style is such that I wait for a shot that really appeals to me rather than just shooting a lot of things. If the number of shots taken is how to measure success, I'm a failure. Sorry if you find these flat and unappealing as you did with my shots posted to illustrate the versatility of the 70-180 Micro-nikkor zoom for Valeria.

 

The purpose of my post here in strobes and lighting three days ago was primarily to say that I thought Ikelite's claim of more flashes and faster recycles with the new Lithium ion battery packs appeared to be true.  I'll attach a few of my new Komodo shots, all taken with TTL, which show some of the results of what was my first underwater experience with the lithium powerpacks and with the D800 in my new Subal housings.  

 

Nothing unusual here, just the usual Komodo suspects.  But I'll keep in mind the old photo cliche, "If your friends don't like your pictures - find new friends!" 

 

Fred

Attached Images

  • Mantas.jpg
  • Lionfish.jpg
  • Fusiliers & surgeonfish.jpg
  • Surgeonfish school.jpg
  • Sponge, crinoids & sun.jpg



#335111 Macro 60 or 105mm on a D800 + (maybe) TC 14-EII or TC-20EIII

Posted by divegypsy on 31 July 2013 - 10:30 PM

Tim, You are absolutely right. The flexibility of a zoom lens like the 70-180 is indeed a curse. In the old days, when all I had was either a 60mm or 105mm, and I didn't get the shot, I could always say, "but I had the wrong lens on my camera." Or, "The critter just wouldn't let me get any closer." Or, "The vis was so mediocre I couldn't back up far enough to get the whole thing in the picture." But these days magazine photo editors don't accept such excuses. And when you come back with those excuses instead of the "shot", they find someone else to send to places like Palau or Raja Ampat for them. Someone who they know will get the "shot", even if it means shooting with a 70-180mm. Someone who can deal choosing both a good shooting angle AND a good framing. At the same time! Oh, the curse of trying to make your living as a fish-paparazzi in a time of such optical richness! Fred




#328726 Tokina 16-28 f2.8

Posted by divegypsy on 27 March 2013 - 06:30 PM

I just looked up the photozone test report.  This is one paragraph from their "VERDICT" of the lens.    http://www.photozone...-tokina162828ff

 

"Unfortunately there may be a hair spoiling the (optical) soup here - quality control. As mentioned we purchased three lens samples for testing, two in Nikon and on in Canon mount, and all three showed some centering issues. The initial Nikon variant was so poor that we had to cancel the testing procedure. The second sample, used for this review, was better, but still suffered from slight decentering at the long end."

 

Fred




#313313 Nikon announces the D800

Posted by divegypsy on 21 July 2012 - 07:56 PM

Hello Alexis,

I've bought several D800's but don't have a housing yet. Shot with the D700 underwater on my most recent trip - Bali and South Australia. One of the reasons I may switch to the D800 for underwater use is to cut down on the gear I would have travel with if I continue to shoot underwater with the D700 and topside with the D800. The two cameras use different batteries, which means different battery chargers. And back-up's for those chargers and back-up camera bodies of each type. I also prefer shooting with only one kind of camera body so that when I reach for a particular control button on the camera it is always the same place.

You should also keep in mind that how much difference you would see between the D700 and D800 depends a lot on what you want to do with the pictures. The higher dynamic range of the D800 will be most apparent and advantageous when shooting subjects with high contrast, such as having the sun in the picture. The higher resolution is likely to be visible only if you make very large prints of the full frame or make fairly large prints from a small portion of the whole image area. The theoretical maximum resolution increase, 1.67x, will only be realized if you shoot with top quality lenses at their optimum apertures, which in many cases may not give you the depth-of-field you want or need for the picture.

If you already own a D700, but not a D800, you will probably be able to save a very large amount of money on your underwater kit by buying a used housing for your D700 vs having to buy a new housing and a D800.

Fred