FAQ FAQ  Forum Search   Events   Register Register  Login Login

Mirror lenses (2)

Page  <1 56789 11>
Author
anthills View Drop Down
Newbie
Newbie

Joined: 23 October 2022
Country: United States
Location: Virginia
Status: Offline
Posts: 12
Post Options Post Options   Quote anthills Quote  Post ReplyReply Direct Link To This Post 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 theyíre both faster than I usually manage to focus manually.)   Hooray! I wonder if thereís a Great Blue Heron at the local pond. Or perhaps some Red-Bellied Woodpeckers in the forest.
 



Back to Top
anthills View Drop Down
Newbie
Newbie

Joined: 23 October 2022
Country: United States
Location: Virginia
Status: Offline
Posts: 12
Post Options Post Options   Quote anthills Quote  Post ReplyReply Direct Link To This Post 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

Back to Top
woodrim View Drop Down
Senior Member
Senior Member

Joined: 19 October 2009
Country: United States
Location: Charleston, SC
Status: Offline
Posts: 1975
Post Options Post Options   Quote woodrim Quote  Post ReplyReply Direct Link To This Post 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.
Regards,

woodrim
Back to Top
darosa View Drop Down
Emeritus group
Emeritus group

Joined: 23 March 2007
Country: Netherlands
Location: Old Zealand
Status: Offline
Posts: 13981
Post Options Post Options   Quote darosa Quote  Post ReplyReply Direct Link To This Post Posted: 25 October 2022 at 23:07
Originally posted by anthills anthills wrote:



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.



Very strange indeed! The more so as the lens specification of other Vectis lenses is correct.

And: welcome to Dyxum!
Back to Top
darosa View Drop Down
Emeritus group
Emeritus group

Joined: 23 March 2007
Country: Netherlands
Location: Old Zealand
Status: Offline
Posts: 13981
Post Options Post Options   Quote darosa Quote  Post ReplyReply Direct Link To This Post Posted: 25 October 2022 at 23:11
Here are my first test shots with Vectis 400:

1 Trying to catch donuts


2 The cemetery gate


3 Golden memories


4 Break the chains, and walk in freedom!


all with a7riv + Minolta V Reflex Lens 400mm 1:8 (1997; Vectis, APS; LA-VE2)

All manual focus, just to be sure. Amazingly sharp!
Back to Top
mariuszlo View Drop Down
Senior Member
Senior Member

Joined: 17 December 2007
Country: United States
Location: Jersey City
Status: Offline
Posts: 3165
Post Options Post Options   Quote mariuszlo Quote  Post ReplyReply Direct Link To This Post Posted: 26 October 2022 at 00:59
Originally posted by darosa darosa wrote:


All manual focus, just to be sure. Amazingly sharp!


Better than Minolta Reflex 500mm?
Sony a7R4, a6400. E, A and MD lenses.
 



Back to Top
woodrim View Drop Down
Senior Member
Senior Member

Joined: 19 October 2009
Country: United States
Location: Charleston, SC
Status: Offline
Posts: 1975
Post Options Post Options   Quote woodrim Quote  Post ReplyReply Direct Link To This Post Posted: 26 October 2022 at 01:52
Originally posted by mariuszlo mariuszlo wrote:

Originally posted by darosa darosa wrote:


All manual focus, just to be sure. Amazingly sharp!


Better than Minolta Reflex 500mm?


Although better needs to be defined, in my opinion, yes. Very close to the 250mm except for the slight vignetting.
Regards,

woodrim
Back to Top
darosa View Drop Down
Emeritus group
Emeritus group

Joined: 23 March 2007
Country: Netherlands
Location: Old Zealand
Status: Offline
Posts: 13981
Post Options Post Options   Quote darosa Quote  Post ReplyReply Direct Link To This Post Posted: 26 October 2022 at 08:58
Originally posted by woodrim woodrim wrote:

Originally posted by mariuszlo mariuszlo wrote:

Originally posted by darosa darosa wrote:


All manual focus, just to be sure. Amazingly sharp!


Better than Minolta Reflex 500mm?


Although better needs to be defined, in my opinion, yes. Very close to the 250mm except for the slight vignetting.


+ 1
Back to Top
neilt3 View Drop Down
Senior Member
Senior Member

Joined: 13 September 2010
Country: United Kingdom
Location: Manchester.U.K
Status: Offline
Posts: 3186
Post Options Post Options   Quote neilt3 Quote  Post ReplyReply Direct Link To This Post Posted: 26 October 2022 at 10:09
Originally posted by anthills anthills wrote:

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.

.


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 .
see my photostream on flickr;
http://www.flickr.com/photos/neilt3/
C & C welcome.
Back to Top
anthills View Drop Down
Newbie
Newbie

Joined: 23 October 2022
Country: United States
Location: Virginia
Status: Offline
Posts: 12
Post Options Post Options   Quote anthills Quote  Post ReplyReply Direct Link To This Post Posted: 26 October 2022 at 12:18
Thereís a reset, which just resets some preferences to defaults, and initialize, which seems to be a thorough wipe. I did the latter.

Meanwhile Iíve done some more shooting. I have multiple copies of the Vectis 400 and Iím having sporadic performance issues with the LA-VE2. It seems better than prior to the reinitialize but still not great. Sometimes it stalls and wonít respond for a while; sometimes it hunts and gives up.

I also have one copy of the Vectis 400 that it wonít 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 ďF90 Ī0.0Ē 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 didnít 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 havenít 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 Iíd 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 Iíve 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.
Back to Top
neilt3 View Drop Down
Senior Member
Senior Member

Joined: 13 September 2010
Country: United Kingdom
Location: Manchester.U.K
Status: Offline
Posts: 3186
Post Options Post Options   Quote neilt3 Quote  Post ReplyReply Direct Link To This Post 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.
see my photostream on flickr;
http://www.flickr.com/photos/neilt3/
C & C welcome.
Back to Top
anthills View Drop Down
Newbie
Newbie

Joined: 23 October 2022
Country: United States
Location: Virginia
Status: Offline
Posts: 12
Post Options Post Options   Quote anthills Quote  Post ReplyReply Direct Link To This Post 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.
Back to Top
darosa View Drop Down
Emeritus group
Emeritus group

Joined: 23 March 2007
Country: Netherlands
Location: Old Zealand
Status: Offline
Posts: 13981
Post Options Post Options   Quote darosa Quote  Post ReplyReply Direct Link To This Post 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.
Back to Top
woodrim View Drop Down
Senior Member
Senior Member

Joined: 19 October 2009
Country: United States
Location: Charleston, SC
Status: Offline
Posts: 1975
Post Options Post Options   Quote woodrim Quote  Post ReplyReply Direct Link To This Post 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.



Regards,

woodrim
Back to Top
Dyxum main page >  Forum Home > Dyxum Photographs > Themed Views Page  <1 56789 11>

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.266 seconds.

Monitor calibration strip

Dyxum.com - Home of the alpha system photographer

In memory of Cameron Hill - brettania

Feel free to contact us if needed.