Mirror lenses (2) |
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anthills
Newbie Joined: 23 October 2022 Country: United States Location: Virginia Status: Offline Posts: 12 |
Post Options Quote Reply Posted: 24 October 2022 at 16:20 | ||
Both of my MonsterAdapter adapters are behaving better after Settings -> Reset -> Initialize. I have no idea what the problem was; I never found any focus-related settings that seemed to be changed from defaults. But something surely was.
Now both the Vectis 400 on the MonsterAdapter LA-VE2, and the Minolta 500 on the Sony LA-EA4 with MonsterAdapter circuit board and sans translucent mirror, are focusing with reasonable speed and accuracy. I have Focus Area set to Center, and they are working well in both AF-C and AF-S focus mode. (Neither is as fast or accurate as a modern lens, but they’re both faster than I usually manage to focus manually.) Hooray! I wonder if there’s a Great Blue Heron at the local pond. Or perhaps some Red-Bellied Woodpeckers in the forest. |
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anthills
Newbie Joined: 23 October 2022 Country: United States Location: Virginia Status: Offline Posts: 12 |
Post Options Quote Reply Posted: 24 October 2022 at 18:44 | ||
I had a nice walk with the Vectis 400. I took along the Minolta 500 as well but didn't use it this time. No herons, but a lovely red-tailed hawk, and a crow with fall foliage donuts in the background. I haven't figured out how to post images here yet, so no image to share for now.
The LA-VE2 adapter puts some information into the EXIF, but for some odd reason, some of it is inconsistent. The focal length is recorded in a multiple places, as is the f-stop (400mm, 405mm, f8, f8.3). In some programs, the lens is listed as "Sony 400-4mm f8.3" for example. I did some archaeology and found that in the photo processing programs I use, the Sony::LensSpec is given priority over the usual EXIF::LensInfo, and that's where that odd-looking zoom specification with 4mm comes from. It's apparently similar to EXIF::LensInfo, according to the exiftool documentation, but it isn't really specified. Apparently you can set a flag in it to denote a reflex lens, and perhaps you can specify Minolta as the maker instead of Sony. I'll fiddle with it more later and see what I find out, but for right now, I saved a preset in MetaImage, my favorite graphical front-end for exiftool, to overwrite the values as follows. This is only something I do with JPGs, I don't dare mess with raw files since I corrupted some. Exif Lens Info: 400 400 8 8 Exif F Number: 8 Exif Lens Make: Minolta Exif Lens Model: Minolta Vectis 400/8 [this is free-text] Exif Focal Length: 400 Exif Focal Length in 35mm Format: 400 Sony Lens Spec: 00 400 0 8 0 00 |
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woodrim
Senior Member Joined: 19 October 2009 Country: United States Location: Charleston, SC Status: Offline Posts: 1975 |
Post Options Quote Reply Posted: 24 October 2022 at 22:26 | ||
Welcome, anthills, I'm glad to hear that you have solved the AF problem. I'm also happy to see you here at Dyxum. I think you have a lot to offer and much to gain from the very talented and knowledgeable people here.
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Regards,
woodrim |
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darosa
Emeritus group Joined: 23 March 2007 Country: Netherlands Location: Old Zealand Status: Offline Posts: 14173 |
Post Options Quote Reply Posted: 25 October 2022 at 23:07 | ||
Very strange indeed! The more so as the lens specification of other Vectis lenses is correct. And: welcome to Dyxum! |
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darosa
Emeritus group Joined: 23 March 2007 Country: Netherlands Location: Old Zealand Status: Offline Posts: 14173 |
Post Options Quote Reply Posted: 25 October 2022 at 23:11 | ||
mariuszlo
Senior Member Joined: 17 December 2007 Country: United States Location: Jersey City Status: Offline Posts: 3809 |
Post Options Quote Reply Posted: 26 October 2022 at 00:59 | ||
Better than Minolta Reflex 500mm? |
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Sony a7R4, a6400. E, A and MD lenses.
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woodrim
Senior Member Joined: 19 October 2009 Country: United States Location: Charleston, SC Status: Offline Posts: 1975 |
Post Options Quote Reply Posted: 26 October 2022 at 01:52 | ||
Although better needs to be defined, in my opinion, yes. Very close to the 250mm except for the slight vignetting. |
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Regards,
woodrim |
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darosa
Emeritus group Joined: 23 March 2007 Country: Netherlands Location: Old Zealand Status: Offline Posts: 14173 |
Post Options Quote Reply Posted: 26 October 2022 at 08:58 | ||
+ 1 |
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neilt3
Senior Member Joined: 13 September 2010 Country: United Kingdom Location: Manchester.U.K Status: Offline Posts: 3519 |
Post Options Quote Reply Posted: 26 October 2022 at 10:09 | ||
That might solve the issues I'm having with mine in the a7Riv. When you do the reset , does it clear all the settings on the camera back to factory default ? ie what the custom key settings for etc . |
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anthills
Newbie Joined: 23 October 2022 Country: United States Location: Virginia Status: Offline Posts: 12 |
Post Options Quote Reply Posted: 26 October 2022 at 12:18 | ||
There’s a reset, which just resets some preferences to defaults, and initialize, which seems to be a thorough wipe. I did the latter.
Meanwhile I’ve done some more shooting. I have multiple copies of the Vectis 400 and I’m having sporadic performance issues with the LA-VE2. It seems better than prior to the reinitialize but still not great. Sometimes it stalls and won’t respond for a while; sometimes it hunts and gives up. I also have one copy of the Vectis 400 that it won’t operate; the camera screen shows an image briefly as the camera turns on, but then the display washes out to white, and along the bottom, it blinks “F90 ±0.0” as if an F/90 lens is attached. The camera will then not release the shutter in any mode, even M. This copy of the lens has no damage or problems that I can see, e.g. the contacts look fine. I have a Vectis S-1 camera and it operates this copy of the lens without problems. In fact, testing the lens on the Vectis S-1 camera gave me some perspective on AF performance relative to the LA-VE2 adapter: the old camera is actually better at focusing the lens than the LA-VE2 is. It frequently hunts but never fails to respond and always locks onto focus after hunting. I tried contrast-detect autofocus on my Sony a7r3 with the LA-VE2. That didn’t work at all! Phase-detect is the only thing that is working for me. I have tried Center and Flexible Spot. On some of my other cameras I can shrink the focus zone to a single point dead-center, but I haven’t figured out how to do that on this Sony; is it possible? All I can seem to do is shrink it to a zone that seems to be a grid of about 4x4 or 5x5 focus-detection points. As far as optical quality of the lenses, I have done some quasi-objective testing under somewhat controlled conditions. I have one copy of the Vectis 400 that is exceptionally sharp and contrasty despite actually having some light dust and even a barely visible fringe of haze around the perimeter of the primary mirror. My other copies that look cleaner and more pristine are very close, optically. One of them was ghastly-bad until I noticed that there was a UV protection filter installed between the front of the lens and the short screw-on hood, which I’d previously failed to notice. Removing that made a huge difference. These lenses are very revealing of anything messing with their optics. Away from the bench, I have gotten exceptionally sharp and contrasty photos from the Vectis 400 in real-world usage. If you have a good copy, as far as I am concerned it demonstrates that mirror lenses are not inherently limited to subpar performance, even on high-resolution modern sensors. And from what I’ve seen, copy variance is low; I think these were built to a very high standard. I have a lot of mirror lenses and finding good copies of most of them has involved a lottery, but not so with the latter-day Minoltas. |
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neilt3
Senior Member Joined: 13 September 2010 Country: United Kingdom Location: Manchester.U.K Status: Offline Posts: 3519 |
Post Options Quote Reply Posted: 26 October 2022 at 13:14 | ||
Thanks . I'll try the reset when I get home .
I've three of the Minolta 400mm's plus the Minolta 500mm reflex . But apart from the 400mm misbehaving ( I've not tried the two spares ) the 17mm is a bit erratic and the 25-150mm really isn't happy ! I'll try the reset first , then I'll try my extra copies. Used on the original adapter from 2015 , ally lenses were giving sharp results manually focused on the NEX 7. |
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anthills
Newbie Joined: 23 October 2022 Country: United States Location: Virginia Status: Offline Posts: 12 |
Post Options Quote Reply Posted: 26 October 2022 at 14:10 | ||
I found an answer to my question about shrinking the focus spot. When I use the Fn menu to select the Focus Area, when scrolled to Flexible Spot, I can use the right/left arrows to choose L, M, or S. The S spot is pretty close to the "single point" I was looking for. It's rainy out right now so I will have to test the Vectis 400 later and see if using a very small focus area helps with the LA-VE2.
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darosa
Emeritus group Joined: 23 March 2007 Country: Netherlands Location: Old Zealand Status: Offline Posts: 14173 |
Post Options Quote Reply Posted: 26 October 2022 at 15:15 | ||
My 25-150 is very unhappy too, it has the F90-washed-out-white-display syndrome. Just ordered another one, new old stock in box; hope that's happy to see some action at last. They're still cheap.
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woodrim
Senior Member Joined: 19 October 2009 Country: United States Location: Charleston, SC Status: Offline Posts: 1975 |
Post Options Quote Reply Posted: 26 October 2022 at 16:02 | ||
Hmmm, I don't recall having that problem but had only done a brief test of the lens after receiving it. I'll give it another try.
I suggest you share with the Monster people all these issues you find. I expect that the adapters will have updates to the firmware like the LA-EA4 conversion did. It may also be possible to learn from them what AF settings they used for their testing. I suspect a great deal of the difficulty is related to those settings. When I was testing my prototype LA-VE2, I made changes to my AF settings after having trouble. At this time I don't recall exactly what I did and I don't know much about using AF anyway. I also had two friends try the adapter on their A7rIV cameras; one worked well and the other had challenges. It was settings related. |
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Regards,
woodrim |
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