BastianK wrote:
In case we see significant improvements we can start our hunt for the lousiest (= shortest) adapter
I also think 2m maximum focus distance might work for me.
No problem unscrewing the filter for work at infinity.
PS: I think we might see the Minolta Close Up No.0 prices skyrocket...
The ill-effect of the induced field curvature is never an issue at infinity for me as I step the lens down to at least f/6.3 but at close distances and wider apertures, I see it in some of my images. Usually when the subject is at 1 to 2 meters distance. The Minolta close up filter is made of high quality glass and if it fixes this, it would be great. I'm not sure what's the average price for it, I bought mine for $10 at Keh.
Fred Miranda wrote:
The ill-effect of the induced field curvature is never an issue at infinity for me as I step the lens down to at least f/6.3 but at close distances and wider apertures, I see it in some of my images. Usually from 1 to 2 meters. The Minolta close up filter is made of high quality glass and if it fixes this, it would be great.
I second all of that.
Just so some are aware, I have tried a 2m B52 Proxar by Zeiss on the 35mm Distagon ZM, and did not notice much of any sharpness improvements in the corners compared to it off.
Nothing like the massive boost I saw with the 18, 25 and 28mm ZM lenses.
I did not test field curvature though, so this may be something it does address still.
Fred and I, we both care way more for influence the field curvature has on the bokeh.
Phillip had best results on his Ultron 35mm 1.7 with the weak 0.4m Tokina lens.
But as the ZM 35mm 1.4 is a floating elements / rear focus lens things may be more complicated here.
With 5 different filters though, maybe one will give decent improvements.
Fred Miranda wrote:
An adapter that may work is the Hawks because it has infinity adjustment. I don't own it anymore but I remember I could adjust it to pass infinity.
BastianK wrote:
Thanks for pointing that one out to me!
Ordered one dirt cheap (probably cheaper than sending it from Andorra -> Germany) from eBay to add to my review staple.
Phillip also offered to send me his Tokina close up lens he used for the Ultron.
I did not yet manage to get the Minolta 72mm 0.43 dptr, on ebay it is only availabe in a set with the 100-500mm 8.0 lens for 400$ (which I am obviously not interested in) :-/...Show more →
You got serious about this!
We need to make sure the glass is achromatic, otherwise CA will be an issue.
For example Tokina offers +0.5 and +0.4. Only the +0.4 is achromatic. (Seems to be the one you got)
It seems that the weaker the diopter, the larger the filter thread.
I'm hoping the Minolta will work well at +0.9 (49mm) for our needs. If it works up to 2m and fixes the FC, it will be on my lens most of the time unless I'm shooting landscapes.
Fred Miranda wrote:
You got serious about this!
Yeah that whacky boken isn't making me really happy...
At certain distances the Loxia 35mm 2.0 shows better bokeh towards the borders.
We need to make sure the glass is achromatic, otherwise CA will be an issue.
The Zeiss Ikon is very old as it seems, but was the only 2m one I could find with a normal filter thread.
The newer Zeiss Proxar lenses in fact also offter T* coating, but they are expensive and have a Hasselblad bayonet, hard to adapt.
It seems that the weaker the diopter, the larger the filter thread.
One could say for everyone but us the weaker close up lenses are of less interest ^^
I'm hoping the Minolta will work well at +0.9 (49mm) for our needs. If it works up to 2m and fixes the FC, it will be on my lens most of the time unless I'm shooting landscapes.
I hope that, too. If not the Leica Elpro4 or the Nikon No.0 may be a good compromise of size and effect. At least I hope so.
DavidBM wrote:
Yep better to take an adapter to a machine shop and get it shortened a bit, or try it yourself with a cheap one. If it really works with no other costs then I'd think it worthwhile to get a decent adapter ground down and look for a weak closeup with great coatings to use this lens (this and the ZM distagon are both lenses I haven't thought worth getting for the price because of curvature issues on the A7 series, and funky mid to close distance bokeh on the distagon, wonderful though they both are in many ways)
This would be really easy to do with an LTM-E adapter. Then use an LTM-M adapter. At least for testing.
My two LTM adapters are very simple, with a ring in the center with M39 threads on the inner surface. It should be relatively straightforward to shave it down a bit to shorten it, even without access to a machine shop or specialized metalworking tools.
I think you mistake how LTM to M adapters work. I will just say: the other way round.
The ZM 35mm 1.4 only comes in M mount, there is no adapter to mount it on LTM.
arduluth wrote:
This would be really easy to do with an LTM-E adapter. Then use an LTM-M adapter. At least for testing.
My two LTM adapters are very simple, with a ring in the center with M39 threads on the inner surface. It should be relatively straightforward to shave it down a bit to shorten it, even without access to a machine shop or specialized metalworking tools.
Leica screw to M adapters are (or should be) precisely 1mm thick, so not much scope for thinning down signicantly! Most of my Leica M and Nikon adapters both to Sony and now Fuji have been too short, but only slightly so the lens focuses past infinity, shims inserted to correct this sloppy workmanship have been between 0.085 and 0.2 mm. If this sort of amount is what your after, then it shouldn't be too difficult to find.
gyoung143 wrote:
Leica screw to M adapters are (or should be) precisely 1mm thick, so not much scope for thinning down signicantly! Most of my Leica M and Nikon adapters both to Sony and now Fuji have been too short, but only slightly so the lens focuses past infinity, shims inserted to correct this sloppy workmanship have been between 0.085 and 0.2 mm. If this sort of amount is what your after, then it shouldn't be too difficult to find.
Gerry
Sorry, I wasn't clear - the LTM-M adapter isn't changed, but the inner ring of the LTM-E adapter would be very easily shortened by up to a few millimeters.
I had gotten some various grades of sand paper and used my calliper to lap down the surface of a cheap adapter I got off eBay. To get the ZM Biogons to a level where they would reach infinity, I had to lap down approx 0.5mm
arduluth wrote:
Sorry, I wasn't clear - the LTM-M adapter isn't changed, but the inner ring of the LTM-E adapter would be very easily shortened by up to a few millimeters.
Some LTM->E Adapters would be easy to shorten, yes, but this would only work for LTM lenses, not M.
arduluth wrote:
Hence the LTM-M adapter...
In the whole equation, there is no LTM!
Lens has M-mount.
There is no M->LTM adapter possible.
You need an M->E adapter.
BastianK wrote:
In the whole equation, there is no LTM!
Lens has M-mount.
There is no M->LTM adapter possible.
You need an M->E adapter.
Bahhh, it's the other way around - you can adapt LTM lenses to M, but not the other way around. My bad! Shame, because it'd be so easy to make that LTM ring shorter vs a modifying a bayonet mount.
arduluth wrote:
it'd be so easy to make that LTM ring shorter vs a modifying a bayonet mount.
True
I already received today:
Tokina 72mm / 2.5m / 0.4 dptr
Minolta No. 0 49mm / 1.07m / 0.94 dptr
So the weakest and strongest of my list.
I am not ready to post results yet (got home at 6pm where it was already very dark)
but in terms of yielding a flat field (yes, Bokeh is improved) the Minolta No.0 seems to be the way to go.
Keep in mind though: I only investigated the situation at ~1.2 m distance so far,
which is also pretty much the maximum focus distance with the Minolta filter attached :/
You also notice a change in field of view, I will examine how much exactly, but I think we are talking 2-3mm more here.
I already received today:
Tokina 72mm / 2.5m / 0.4 dptr
Minolta No. 0 49mm / 1.07m / 0.94 dptr
So the weakest and strongest of my list.
I am not ready to post results yet (got home at 6pm where it was already very dark)
but in terms of yielding a flat field (yes, Bokeh is improved) the Minolta No.0 seems to be the way to go.
Keep in mind though: I only investigated the situation at ~1.2 m distance so far,
which is also pretty much the maximum focus distance with the Minolta filter attached :/
You also notice a change in field of view, I will examine how much exactly, but I think we are talking 2-3mm more here....Show more →
That's great news Bastian.
It would be great to have some before/after comparisons with the Minolta filter whenever you can.
If you post the full files or 1:1 crops we can examine if there changes in center/edges resolution, color cast and bokeh.
Too bad it's only 1.2m...but perhaps that can be improved using a modded adapter or the Hawks with infinity tweak.
Fred Miranda wrote:
It would be great to have some before/after comparisons with the Minolta filter whenever you can.
If you post the full files or 1:1 crops we can examine if there changes in center/edges resolution, color cast and bokeh.
I will run systematic tests as soon as all 5 filters have arrived.
Otherwise I would have to do the same work again and again...
