Subal 105vr Port + Nikon 5T

Well I finally got to try out Ryan Canon's suggestion to take my Nikon 5T and 6T diopters - with the black rings removed - and attach them to the front of my Nikon 105vr lens. As many of you know this dedicated Subal 105vr port doesn't have room for any screw on diopter (aaargh!!!). And if you have tried extension rings as I have the MF doesn't line up and often the lens is not supported right.

What a problem. (And yes I also have a Woody's Wet Diopter, but I do believe that the Nikon 5T did produce nicer photographs than my Woody's with the same 105vr lens)

So Ryan suggested something he said he learned from the Tacketts (it is in their book). Unscrew the black ring around the diopter and attach to the front of the lens with "blu tak". There isn't room to stack diopters using this method but you can easily get the 5T or 6T in there.

Drawbacks are you then can't use your diopters topside easily (it is hard to get those rings on and off), and I find the diopters harder to store properly.

But at least I can use them. This way in conjunction with a kenko 2X TC and I believe the 15mm & 35mm ex rings; or the kenko 1.4X TC with the 20mm ex ring and 5T or 6T attached in this way with blu tak - the MF of the Subal 105vr port can still be used which is beneficial in many instances.

Here's a quick pic after a dive with the 5T - all happily cradled with blu tak (probably a bit too much???) :

Nice solution, Carol. Or should that be thanks Ryan, or the Tacketts! Anyway, thanks Carol for sharing.

I don't use the standard Subal 105 VR port - so I can fit either the 5T or 500D (with step up ring) on the front of the 105mm.

Alex

Nice solution, Carol. Or should that be thanks Ryan, or the Tacketts! Anyway, thanks Carol for sharing.

 

I don't use the standard Subal 105 VR port - so I can fit either the 5T or 500D (with step up ring) on the front of the 105mm.

 

Alex

Yes, Alex I know this and I do think that your solution for the 105vr lens is better (and cheaper). The Subal dedicated 105vr port does have the MF but I don't think it is worth it. Still I have it so I'll mess with it....... ...

Cheerio, Carol

I would be a little concerned about image quality loss with a close-up lens that is held in place with glue rather than the precision of the regular threaded mount. I would be concerned that the close-up lens is not precisely centered. And if it is not, that images made with the combo might in fact lose so much sharpness that you would be better off shooting at 1:1 and using photoshop to crop the image and interpolate pixels to the size of the combo.

Have you shot test shots, perhaps on land initially, to see if there is any difference?

Fred

I would be a little concerned about image quality loss with a close-up lens that is held in place with glue rather than the precision of the regular threaded mount. I would be concerned that the close-up lens is not precisely centered. And if it is not, that images made with the combo might in fact lose so much sharpness that you would be better off shooting at 1:1 and using photoshop to crop the image and interpolate pixels to the size of the combo.

 

Have you shot test shots, perhaps on land initially, to see if there is any difference?

 

Fred

Fred,

No I haven't done any test shots on land. Perhaps the Tacketts have as they have stated in their book that if the diopter doesn't fit in the port - remove the black ring and attach with blu tak. Or perhaps Ryan Canon, who suggested it to me, has tested this. Or perhaps Alex has an idea on this.

It is a significant problem if you want to use a diopter with the 105vr lens if you purchased Subal's dedicated port...... With the 105vr lens and screwing on the Nikon 5T or 6T If you just use an additional 15mm ex ring the lens can easily be skewed off center and fail to operate (happened to me) and of course you lose manual focus (the whole idea behind the port). Also Ryan Canon told me he would be concerned using the Subal dedicated 105vr port with extension rings as without the MF knob lined up the lens is not held and supported in the port like it should be.

You know the Nikon 5T/6T are not precision made to go with the 105vr lens so I don't really know how much difference there is in actuality between attaching with blu tak and using the screw on option. I did notice it was difficult to tell (at least with the 5T) - with the black ring removed - exactly which side faces out as there is not a lot of noticeable curvature, at least with the 5T and I may have goofed up there possibly

Some of my shots suffered from some lack of sharpness but that is because I was experimenting with slow shutter speed and shallower DOF to produce nice bright and softer backgrounds (especially because Blue Heron Bridge doesn't typically have much in the way of nice background opportunities....... ); I also tried to use the shallow DOF (in conjunction to slower shutters where appropriate), to minimize particles that pass by in the tidal flow there and home in on specific parts of the creature. I failed sometimes, but I think it was due to using apertures less than 16 in conjunction with the 105vr and the 5T attached with blu tak. I don't really think the 105vr alone would have been that much sharper alone (without the diopter w/blu tak) given similar settings and then of course cropping an image/interpolation as you proposed softens it a bit also and of course you can't get quite as close to the subject u/w which is the reason for the diopter with the 105vr (as I think the average min subject distance with that lens is about 11" w/o diopter and that's a little far in less than perfect, close macro conditions). But I certainly could be wrong?

Also I'm a very conservative "sharpener" in Lightroom or PS and I should probably sharpen my images more - but I tend to err on too little sharpening. I use no in camera sharpening in my Nikon d200 so that might actually make more of a difference than if the diopter is attached with a black ring or blu tak if one is honing in on sharpness of the macro image?? Lots of variables?

Again possibly someone with more experience with the diopters and attaching them, the dedicated Subal 105vr port, etc has more data on the best way to go about it and if sharpness is lost because of a diopter attached with blu tak or if that is not a significant issue.

Thanks for the info, Carol

I think Fred raises a useful word of caution that attaching a dioptre with blu-tack instead of using the screw thread could lead to it being slightly off centre or not exactly parallel with the front element of the lens. With obvious issues to sharpness across the entire frame. Sharpness at the point of focus would be indistinguishable (unless the dioptre was really skew).

Doing a couple test shots before each dive (on land) of a subject parallel to the lens would reassure you that the dioptre was correctly aligned. Probably only worth it if you were planning to shoot subjects that filled the entire frame and you want to be completely sharp corner to corner (e.g. anemonefish eggs).

Alex

I don't see test shots being much help, because I'd expect most people would regularly remove the 5T - and it would be . Furthermore or never likely to move in transit on the blu-tack.

Thanks Alex and Fred so much for your expert input.

But this also brings up this point. Say I was trying to use the Nikon 5T in the Subal 105vr port - had to attach it w/blu tak, carefully of course - but the whole point of doing this is to get better quality than with the Woody's wet diopter (that I also have for the 105vr).

Seems though if you all are talking slight variable with the 5T diopter attached with blu tak affecting quality across the frame then it would seem to me that any attachable wet diopter (like the woody's or even the better quality macro-mate) really skews the focus towards the edges. A wet diopter, even a fixed or flip wet diopter, gets affected by volume of water/air trapped, pressure changes and lots of different factors - much more than attaching something inside the port with blu tak.

So I guess I'm saying is attaching the 5T with blu tak in the Subal 105vr port even worth doing vs say the Woody's? Of course the 6T should be worth it as the Woody's isn't comparable there.

I did notice though when I did attach the 5T (and I actually do think I had it facing the correct way), anyway I noticed when I first attached it the blu tak did make it skew differently, but with careful pressing I do believe I had it pretty "level". I don't know how much shall I call it "slant" you would need to affect an image underwater? But it was pretty unmovable after careful attachment so from side to side couldn't have been off by more than a fraction of millimeter - or off center by the same amount.

Fred does bring up a good point though too that I thought of. The black, screw on rings do hold the diopter slightly farther away from the lens so I don't know how this affects things - if it is noticeable or not.

You know if Subal has just given us a little more space in their 105vr port to use a screw on diopter (a common thing with the 105) then this post/effort would be unnecessary. (But then I'm learning a lot so that is a good end in itself).

Thanks Again Alex and Fred! Carol