Rivkin

I like what I see but i am away from books. Does look like early Muromaci Bizen and i personally would be a bit more comfortable with 1440. Signature is well done

There are plenty of activities, but the only way there is such a significant difference for a blade seen from above with light on a side and seen at an angle is if nie is below certain size... or there is a huge polishing issue. The latter should not be the case here, so nie size is small.

Very strong jigane, but if one don't see hamon on top-down photos of eirakudo it means its nioi with maybe ko nie.

Thank you very much, that probably it!

I read "ko" followed maybe by tsugu?? Any help would be greatly appreciated. Its an interesting blade I picked up and I will try to post more photos later...

I appreciate the vote of confidence, but I see the same - there are some issues, though shintetsu like this is probably not a great problem here - it does look like a typical sue Bizen in suguha.

With such boshi I would say Tametsugu appears as quite possible outcome.

With such strong nie Naminohira excluded. This is most likely Uda. I would say Yamato Shizu or Shikkake are distant, but possible. Timewise I would lean towards early Muromachi. There is also possibility its early Kaga Fujishima, which is basically other way to interpret Uda features.

It has some Soshu to it, but Yamato also feels very strong here. Uda is a possibility. Tametsugu is optimistic outcome.

The magnification/resolution is unfortunately not there. What is seen is that hada is masame dominated, hamon is ko nie to nie deki, suguha with a bit of gunome, midare. Definitely koto, but without high res pictures its hard to say something more specific. Nakago sustained significant damage which will scare a lot of people to think its saiha, but the work does not lean this way. It can be Naminohira. Or Yamato shikkake. Finally, Uda is definitely worth consideration. The most optimistic outcome is Yamato Shizu. Period can be later... High resolution would be nice, also boshi [!]. If hamon widens towards yokote its a common Muromachi trait. In general it feels like the photos are good enough to identify, they've just been downsized until not much is seen...

I think you are right. I scanned the sword descriptions pdfs I stored away and got roughly the ratio 12:1:3.5... With a caveat that my pdfs are obviously not representative and if anything they probably over-represent Kunzan and potentially Kanzan. If I take Tanobe-sensei's sayagaki at 3000 that would be 600-1,000 for Kunzan and 25-36,000 for Kanzan.

Hard to estimate because its a non-random selection which tends to cluster around upper TH and Juyo, but one can estimate the ratio between three using just Juyo swords and then guess the number of sayagaki for one of them getting all three. My pure guesstimate would be about 1,200 for Kanzan, 100 for Kunzan and 300 for Tanobe sensei.

Any proven DYI recipes for getting rid of stupid kimpun mei without damaging old and nice patina or its polisher only task?

They never really matched Kongo jigane. O-Sa went Rai first, then Sa went Soshu with very fine jigane and hamon which is sort of choji or suguha nioi with very strong belts of nie. In Muromachi after Oei it mostly reverted to weird provincial Yamato.

Edo period, lots of acid.

I have to admit this one is a bit of a head scratcher. Jigane seems great, but the hamon ... is it mostly nioi and ko nie with strong nie only in couple of places? nioi-guchi which is bright and wide in some places and nearly gone in others? The price... because of Date association? All top Soshu have gained considerably compared to 20 years ago, and the spread between collector to collector and high end retail also increased. But... Anyways, I seriously considered this gentleman: https://www.aoijapan.com/katana-mumei-attributed-to-sa-sadayoshinbthk-tokubetsu-hozon-token/ Personal preference, I would probably like it more than "Go".

I don't think its LED per se, its the size and relative brightness and directiness of light source. As some know, I use very long (seconds) shutter times and "paint" in real life the blade with light, sometimes with different light sources. If you want something generic I would use very wide LED lightstick and hold close to blade's surface. That sort of works for all. For some Soshu to bring up nioi-guchi and nie I use on the contrary portable LED flashlight. It brings up detail much better. What's the blade? Naminohira?

My thinking why its not shinshinto: unless you are dealing with Kiyomaro level, shinshinto cannot do matsukawa-hada or any high contrast jigane without completely tanking the hamon. Its barely visible, either pure nioi or some weird nie which never sparkles. Here we see high contrast jigane but hamon comes up as having also about the same level of contrast. There are exceptions and in hands its possible to say, but also the holes are punched very naturally, with the correct profile and everything. Kamakura: unless you believe in Masamune who started to do hitatsura level activities in late Kamakura, this style of Soshu work is no earlier than 1330. At least "Sadamune", but if its pre Muromachi ts probably northern (jigane) and later. I am more inclined to see here Muromachi work. Either Uda, probably earlier, or Shimada and later. In both cases its likely to be quite good. Though unfortunately not greatly valuable financially.

I am in between Shimada and Uda Kunifusa. Nice piece though.

Very many polishers believe they do. Reasons provided vary - "water trapped inside steel during polishing", "micro-erosion of weaker particles which still held out during polish". Some polishers will request a specific oiling schedule, a few older polishers would recommend continuous uchiko application.

From little that is seen I would say there is equally little reason for Shintogo optimism. But it appears to be an interesting and quality, possibly Soshu tanto from Muromachi (?). Long kaeri? Shimada, Nobukuni etc... but there is a chance its something better. In which case its likely be something northern.

Real. I even ordered AI to issue papers. It messed up the measurements, but that's AI. Still young. Messes up Juyo papers even worse .

Fuyuhiro, late Muromachi.

Very sorry to hear that. My condolences.

The first generation Kunishige is a bit of arcane art, as for a time Hasebe was thought to have began working much earlier than 1350s that we usually see. Whether its true or not is debatable. If its not, there is not much difference between Kunishige and Kuninobu, which is how I would approach it personally. Its a good blade, the nie is a bit harsh rather than cloudy and the hada is a little bit indistinctive, but then the fact that mumei was attributed to specific name is good. Its not "really" ubu... It does not feel like a strong Juyo candidate but as it is, its probably a decent blade. There are very many katana attributed to Hasebe, but signed ones must be exceptionally rare (not with my books). Also katana tend to be all around the place in terms of work itself, more so than ko waki.