Nikon 35mm adapter which works! NO focussing screen.

[red5]

Re-packaged my opteka lenses by unscrewing the retaining rings, and carefully layed thing strips of insulation tape around the inside of the holder. This was to keep the lenses central and prevent them moving about when tightening the retaining ring.

Have been beavering away at trying to balance this thing out and got something I was happy with. Went and filmed some bits and pieces at my parents on Sunday taking it in turn with each camera. Got back and found that in some of the stuff I shot through the adapter there was a softening of the image down the right hand side, while the center and left both look fine. Very disappointed. Got back and found that the one remaining taped joint (still awaiting the last metal filter adapter ring from china) was slightly lop-sided. Decided to glue the joint with epoxy and made a perfectly straight tube. Alas, now I am unable to get a crisp focus on the left hand 20 percent of the screen. If you rotate the whole adapter 180 degrees, keeping the camera where it was, I still get a slightly blurry left hand side. Sigh. Tried many times and with both HV20s, but after hearing mention of the HV20's sensor being off center on several places online I realised that the remaining misalignment may not be something I cant compensate for.

Messed around on monday and found some position where I could get left, right and centre to achieve better focus by splitting the adapter in two and leaving one piece at a slight angle to the other. But this may be exagerating the uneven bokeh issue I had seen. Not sure if the optics would still work the same when upside down. I have now decided it is just not worth carrying on for something which:
1) Adds some chromatic abherration.
2) Has uneven bokeh near the extreme left/right for objects just slightly out of focus (though I have seen the HV20 also do this sometimes)
3) Which is impractical to use, particularly if trying to compensate for an off center sensor.
4) Although seems to offer some shallower DOF with telephoto lenses, given the above issues I don't think its worth the effort

So at this point I am throwing in the towel. I shall publish my final design in a few days and some pictures showing equivalent HV20 vs Nikon lenses shots. This is in the hope that if someone ever wants to try it for themselves and take the design further they may at least save some time. Sorry guys, but I really had high hopes for this at the start and Ive put in a lot of time and effort to get it to this stage. I may be a little harsh in my assessment above, as some of the things mentioned may not be noticable except in certain circumstances. Have a look at the pictures when I put them on (probably the weekend) and you decide.

I will use my canon as nature intended for now but may buy a cheap secondhand AF101 or maybe the Blackmagic cinema camera when it goes on sale in a few months

[red5]

I know I said I'd given up, but it seems I haven't. I think I have managed to correct the misalignment and can get crisp focus on both sides of the screen, and the middle using the adapter. I need to do more tests. Went and filmed outside just before it went dark and the results were encouraging. Rather than post last weeks disappointing efforts I will re-do. All I did was glue another 43-55 step up adapter to the one already there but so the adapter is shifted laterally a few millimeters towards the tape mechanism.

I received a cool little screen this week, 7 inch 1024x600 with a focus assist. 150 pounds from hong kong (ebay) and it has highlighted that effects caused by the sensor being misaligned are visible with the existing HV20 optics. Simply point the camera down and along a carpet. As you manually change focus, from one end of the range to the other you can see the focal areas pass from one side of the screen to the other.

[1]

red5, I just wanted to let you know that I respect your persistence immensely.

You might not get anywhere, but your journey sure is exciting, and I'm sure I'm not alone when I say:

Go red5!

[red5]

Thank you. That means a lot
I've been too busy today to get any further.

[Janke]

One question: Do you have to zoom in the HV cam very far in order to avoid vignetting?

[red5]

Yes, its about halfway. If you watch the graphics for the zoom its in the middle position (4 of 7). f stop reports to be f/2.2 when the photo button is depressed. Ive tried other configurations using three lenses which got the zoom way wide (f/2.0) but there were some CA/bokeh problems creeping in with that. I guess it might be worth trying some of those again with the lens tube offset sideways like it is. I'm also a bit restricted in that I'm awaiting some 57-55 step down rings from china, which are due any day now. This will give me a bit more flexibility in what I can try as currently the only coupling which I can attach to the opteka in the middle of the tube is glued to a #3 macro tube. And properly glued.

I'm setting it up the camera to get some comparison shots now.

[red5]

Please forgive the schoolboy errors below, I haven't messed with the camera for a while, hence
1) Forgot to calibrate the white balance. nikon lens has a yellow tinge unlike my room lights are daylight bulbs(6500k)
2) not enough light. These daylight bulbs also happen to be ENERGY SAVING ! You can see the gain was up due to the pixel errors amongst the fine text
3) Positioning. Didnt match the zoom of the HV20 precisely to what had been shot with the Nikon, so I had to reframe/crop afterwards. I moved the tripod 8 inches forward for the hv20 shots so the lens was firing from the same position as the adapter was. Unfortunately, when compensating for the droop of the lens I wound the tripod up a touch not down like it should have been. Didnt realise what I had done till it was too late.

frontrighthv20.jpgfrontright100mm.jpg

[red5]

rearlefthv20.jpgrearleft100mm.jpg

[red5]

Cereal packets on far left and far right were both 2.7m from the lens, the bottle and disks 2.3m and the candlestick 1.65meters. Bad chromatic abherration on the museli box on the Nikon shot

admittedly the hv20 look crisp and clean and the Nikon a bit grubby.. Like to see the difference with some decent lighting and remember the WB next time

Now, hows this for strangeness. See below how the Nikon has both disks and bottle in focus at the same time, whereas HV20 cant do this, its one or the other, though halfway inbetween didnt look too bad. In the HV20 shot with the bottle in focus (right) , the Yorkshire gold tea box is in focus too. This is what I was on about with the sensor being misaligned.

picture order: Nikon , HV20 left focus HV20 right focus.


mid100mm.jpgmidlefthv20.jpgmidrighthv20.jpg

[Janke]

Sorry to say, but the difference in DOF seems so small, that I wouldn't bother with the adapter at all... aberrations, soft focus and strange coma in the corners is about all you get...

All this just to get the image upside down on tape...

Interesting experiments, though! Thanks for sharing.

[red5]

And finally, redone some nikon shots with a better WB. I didnt want to leave you with those grubby pics. But it still has all the things you mention Janke.

At 3 different focus depths background, mid and foreground...

nikonbetterwb_00.jpgnikonbetterwb_01.jpgnikonbetterwb_02.jpg


Did anyone find the focussing wierdness on the HV20 of interest?

[red5]

Sorry to say, but the difference in DOF seems so small, that I wouldn't bother with the adapter at all... aberrations, soft focus and strange coma in the corners is about all you get...

All this just to get the image upside down on tape...

Interesting experiments, though! Thanks for sharing.

Used the Nanoflash with its FLIP and FLOP on. My screen is mounted upside down too. Which meant I was viewing the HV20 shots upside down. Probably why I wound the tripod the wrong way.

(added later) The slight smearing effect in the corners can be removed by zooming in further. Depends if you want as much of the frame as possible or crisper corners.

[red5]

Todays setup was

HV20
43-55 step up ring glued slightly offset to
43-55 step up ring
opteka 55mm 10x HD MACRO lens assembly
55-57 step up ring
#3 macro tube (nikon)
57-55 step down filter ring (a makeshift equivalent)
Opteka 55mm 10x ... (which has been opened and had the lens reversed)
55-57 step up ring
#3 macro tube
#3 macro tube
macro tube nikon front flange
lens (Nikkor AIS 100mm f/2.8)


You can use 2 x #2 macro tubes to make a #3, 2x #1 to make a #2 etc.

[cgbier]

at a time which I confess I may not have been entirely sober

While this has oftentimes been the starting point of many an interesting project, I'm still not sure what you try to achieve. Your setup reeks more of some high power macro than anything else.

(don't get me wrong - I'm too sober ATM).

[Janke]

Did anyone find the focussing wierdness on the HV20 of interest?

Not really, because it probably is different in my own HV - manufacturing tolerances...

[red5]

Not really, because it probably is different in my own HV - manufacturing tolerances...

I have two hv20's here and during my earlier experiments I couldnt get a flat plane all in focus in either (admittedly through my adapter) but both showing the same type of problem. I suspect the cause is the same.

If anyone would like to give it a go, all you need to try is a tape measure and a tripod. I'd be interested to hear if you get the same. Far objects in a plane 2.7m from lens and two near objects on the left and right of frame at 2.3m. Ive moved things since but I'd say if you have the two near objects with about a foot gap between and zoom in so they are on the edges of shot, you may get a similar effect. Can you hunt around with the manual focus until only the left or right object is in focus????

[red5]

I'd hoped for some more enthusiasm. I accept your criticisms. I apologise if the early claims never being met got peoples backs up. Its not the best solution, and certainly not as good as I thought it was when I started this thread. But I'm sure its more usable in the lighting conditions in which these shots were take in than my static adapter with a focussing screen ever was. Don't get me wrong, there are many people out there making stunning films with DOF adapters, but I wasnt happy with mine, and it wasnt cheap either.

There are limitations with my design, which I have explored and shared here, but surely there are better solutions out there yet to be tried. Im hoping this exercise will encourage someone out there to do better, to gain useful information from what I have tried and try something different. All I wanted was to focus the the output of a 35mm lens onto the HV20s tiny sensor. How hard can that be? For all we know there may be a single lens solution yet to be discovered. But unless people get off their sofas and try, we will never know. Ignore the negativity you may be picking up from this thread. Ignore it I say, get out there, find some other lenses, take apart some broken binoculars, experiment, and post your results here. I for one will enjoy reading them. If one man can get this far, think what we might we achieve with 10 ?

[cgbier]

Your perseverance surely is adorable, and it is a very interesting project. However, it comes a bunch of years too late. 35mm adaptors, and their workarounds, got killed of by useable vDSLR. Many folks have already moved on, and, most likely won't look back.

Disclaimer: This post was not meant to be negative.

[red5]

Your perseverance surely is adorable, and it is a very interesting project. However, it comes a bunch of years too late. 35mm adaptors, and their workarounds, got killed of by useable vDSLR. Many folks have already moved on, and, most likely won't look back.

Disclaimer: This post was not meant to be negative.

You are most certainly correct.

[drapeama]

35mm adaptors, and their workarounds, got killed of by useable vDSLR. Many folks have already moved on, and, most likely won't look back.

I'll stand in the minimal % of the stats then!

[red5]

Have some better lighting available now. Juggling the rings around I think I have found the extremes of what this sort of setup can achieve.

DEEP END: These have a better single plane focus that any of the shots I've posted and a deeper DOF than in the HV20 shots. Once they've loaded keep skipping between pics 1 and 2 (deep) then try between 3 and 4 (shallow) for a good comparison

100mmbright_01.jpg100mmbright_02.jpg


SHALLOW END: These have the shallowest DOF I have produced so far. The focus isn't bad too, but we have lost some of the Field Of View zooming in past the black rings. How the writing on the boxes changes when the candlestick is in focus is the big difference

100mmbrightshallower_00.jpg100mmbrightshallower_01.jpg


The changes that made this happen were the distance between the two optekas (bigger for deep DOF, small for shallow DOF). Its the same lens, the same distance from the subjects, give or take an inch or so. Not sure how the zoom settings compare.

[red5]

The next step should be to try some of my other lenses out and see if any work well with the same shallow setup. I'm hoping there might be some combination with less CA. Theres a lot to try but I'm very short on free time over the next few days.

[red5]

As before, lenses below 100mm, not much different to HV20 in DOF. I did made single lens version which matched the shallow results above, losing a similar amount of field of view. The CA problem never really went away.

But I guess the final nail in the coffin for my experiments is that I have taken delivery of a Panasonic AF101. I can still see a good future for my HV20s, as for run and gun type shooting its portability and deep DOF is also a great plus. I'm thinking a happy combo of the Panny and the Canon might be very useful.

Did anyone ever test their camera for the left/right focus problems I had ?

[Janke]

Did anyone ever test their camera for the left/right focus problems I had ?

Since you asked, I did it just now, and found a minute difference in the "best focus distance" between left & right, but nowhere near as large as yours.

[zagnut]

2) Can't wait to watch them. I'm personally one of the few supporters left in the world of the DOF adapters.

You and I both drapes. And while I don't have a DOF adapter, I've always wanted one but haven't had the time, nor the monies, to mess about with one. This is quite intriguing and I'll have to read it all tomorrow when I'm a little more sober. lol.