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caspert79
Joined: 31 Oct 2010
Posts: 3221
Location: The Netherlands
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 Posted: Mon Jun 24, 2024 1:39 pm Post subject: Minolta MD 24-50/4: is this normal? |
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caspert79 wrote:
Just received this lens from Ebay but noticed something strange.
With the aperture set @ f/4, the aperture looks a little bit closed down @ the 24mm setting.
When zooming to 50mm @ f/4, the aperture is fully open. I don't see an obvious change in exposure on my camera body when I do this.
Is it possible, that the aperture is slightly closed at the 24mm setting, when the aperture ring is @ f/4? Or is there something wrong?
Here's the lens @ f/4, first @ 24mm setting, and then @ 50mm:
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Doc Sharptail
Joined: 23 Nov 2020
Posts: 1213
Location: Winnipeg Canada
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| Posted: Mon Jun 24, 2024 2:42 pm Post subject: |
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Doc Sharptail wrote:
I don't think there's anything wrong there. I have a couple of zooms that do the same thing, to keep the light intensity equal through-out the zoom range. I can't find any differences in what exposure my smarter camera recommends, either.
I think it's one or two of the Tamron's that do that for me.
-D.S.
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D-810, F2, FTN.
35mm f2 O.C. nikkor
50 f2 H nikkor, 50 f 1.4 AI-s, 135 f3.5 Q,
50 f2 K nikkor 2x, 28-85mm f3.5-4.5 A/I-s, 35-105 3.5-4.5 A/I-s, 200mm f4 Micro A/I, partial list.
"Ain't no half-way" -S.R.V.
"Oh Yeah... Alright" -Paul Simon |
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caspert79
Joined: 31 Oct 2010
Posts: 3221
Location: The Netherlands
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| Posted: Mon Jun 24, 2024 2:44 pm Post subject: |
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caspert79 wrote:
| Doc Sharptail wrote: |
I don't think there's anything wrong there. I have a couple of zooms that do the same thing, to keep the light intensity equal through-out the zoom range. I can't find any differences in what exposure my smarter camera recommends, either.
I think it's one or two of the Tamron's that do that for me.
-D.S. |
Thanks for clarifying. |
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michelb
Joined: 24 Dec 2015
Posts: 67
Location: Montréal area,Québec, Canada
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| Posted: Mon Jun 24, 2024 2:55 pm Post subject: |
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michelb wrote:
My MD-III copy does the same as yours.
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Michel B
Interested in Minolta SLR's since 1971 |
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caspert79
Joined: 31 Oct 2010
Posts: 3221
Location: The Netherlands
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| Posted: Mon Jun 24, 2024 3:04 pm Post subject: |
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caspert79 wrote:
| michelb wrote: |
| My MD-III copy does the same as yours. |
Thanks, that’s reassuring! |
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D1N0
Joined: 07 Aug 2012
Posts: 2536
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| Posted: Mon Jun 24, 2024 3:07 pm Post subject: |
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D1N0 wrote:
That is a hack to keep a constant aperture. I have several wide zooms that to that. They are actually 28/3.5-4 lenses but IQ would probably be sub standard when not closed down a bit.
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visualopsins
Joined: 05 Mar 2009
Posts: 11058
Location: California
Expire: 2025-04-11
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| Posted: Mon Jun 24, 2024 3:11 pm Post subject: |
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visualopsins wrote:
A clever albeit mechanically complicated way to get more sharpness at the wide end? Also maybe constant aperture selling point instead of saying a f/3.5-f/4 zoom?
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Cameras: Sony ILCE-7RM2, Spotmatics II, F, and ESII, Nikon P4
Lenses:
M42 Asahi Optical Co., Takumar 1:4 f=35mm, 1:2 f=58mm (Sonnar), 1:2.4 f=58mm (Heliar), 1:2.2 f=55mm (Gaussian), 1:2.8 f=105mm (Model I), 1:2.8/105 (Model II), 1:5.6/200, Tele-Takumar 1:5.6/200, 1:6.3/300, Macro-Takumar 1:4/50, Auto-Takumar 1:2.3 f=35, 1:1.8 f=55mm, 1:2.2 f=55mm, Super-TAKUMAR 1:3.5/28 (fat), 1:2/35 (Fat), 1:1.4/50 (8-element), Super-Multi-Coated Fisheye-TAKUMAR 1:4/17, Super-Multi-Coated TAKUMAR 1:4.5/20, 1:3.5/24, 1:3.5/28, 1:2/35, 1:3.5/35, 1:1.8/85, 1:1.9/85 1:2.8/105, 1:3.5/135, 1:2.5/135 (II), 1:4/150, 1:4/200, 1:4/300, 1:4.5/500, Super-Multi-Coated Macro-TAKUMAR 1:4/50, 1:4/100, Super-Multi-Coated Bellows-TAKUMAR 1:4/100, SMC TAKUMAR 1:1.4/50, 1:1.8/55
M42 Carl Zeiss Jena Flektogon 2.4/35
Contax Carl Zeiss Vario-Sonnar T* 28-70mm F3.5-4.5
Pentax K-mount SMC PENTAX-A ZOOM 1:3.5 35~105mm, SMC PENTAX ZOOM 1:4 45~125mm
Nikon Micro-NIKKOR-P-C Auto 1:3.5 f=55mm, NIKKOR-P Auto 105mm f/2.5 Pre-AI (Sonnar), Micro-NIKKOR 105mm 1:4 AI, NIKKOR AI-S 35-135mm f/3,5-4,5
Tamron SP 17mm f/3.5 (51B), Tamron SP 17mm f/3.5 (151B), SP 500mm f/8 (55BB), SP 70-210mm f/3.5 (19AH)
Vivitar 100mm 1:2.8 MC 1:1 Macro Telephoto (Kiron)
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Dejan
Joined: 05 Jan 2021
Posts: 151
Location: Belgrade, Serbia
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| Posted: Mon Jun 24, 2024 5:58 pm Post subject: |
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Dejan wrote:
| D1N0 wrote: |
| That is a hack to keep a constant aperture. I have several wide zooms that to that. They are actually 28/3.5-4 lenses but IQ would probably be sub standard when not closed down a bit. |
That is the case with 35-70mm F3.5 lens. Some even modify it to perform as F2.8 lens at 35mm, and it does perform worse that way, but I'm guessing that they did this more to avoid having a variable aperture; making the lens more "pro" or whatever. |
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kiddo
Joined: 29 Jun 2018
Posts: 1273
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| Posted: Tue Jun 25, 2024 11:16 pm Post subject: |
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kiddo wrote:
| Dejan wrote: |
| D1N0 wrote: |
| That is a hack to keep a constant aperture. I have several wide zooms that to that. They are actually 28/3.5-4 lenses but IQ would probably be sub standard when not closed down a bit. |
That is the case with 35-70mm F3.5 lens. Some even modify it to perform as F2.8 lens at 35mm, and it does perform worse that way, but I'm guessing that they did this more to avoid having a variable aperture; making the lens more "pro" or whatever. |
I was gonna do it for both macro and not macro 35-70mm Minolta 3.5, but if it only affects the wider aperture on 35mm FL, it's not really worth it I guess |
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