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lorriman
Joined: 16 May 2008
Posts: 34
Location: UK
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 Posted: Thu Jul 01, 2010 3:45 pm Post subject: Tamron 90/2.5 52BB - help for ghosting test with Canon 450D |
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lorriman wrote:
I just fleabayed the Tamron 90/2.5 55BB and then shortly after discovered to my horror that it has a blue sensor reflection ghost at f8 and smaller due to primitive coatings (and reduced contrast otherwise). It arrives soon. This is a real issue for me as I intended to use it for snapping negatives with my brother's 450D DSLR and I need that f8 aperture (or smaller). I had thought that the coatings were adequate but didn't read far enough and in any case the reports are confused since actual test pics are only from the 52B (an earlier lens).
However I've also learned that this problem may be insignificant if the DSLR sensor is CMOS rather than CCD as they don't reflect as much.
Would someone with this lens and a 450D be able to test this for me? I can't get hold of my brother's camera soon enough but must get a usable lens ASAP. I would rather avoid a second purchase. I might try a kiron next time.
It would also be very interesting to see the same test with the predeccessor 52B (single B) which supposedly has worse coatings. CMOS sensors may make a whole lot of MF lenses viable. |
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lorriman
Joined: 16 May 2008
Posts: 34
Location: UK
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| Posted: Thu Jul 01, 2010 3:48 pm Post subject: |
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lorriman wrote:
Actually another lens that might be interesting is the Tamron 90/2.8 72B. Supposedly the coatings are again an improvement. But maybe not enough? And if they are perhaps they are even enough to cope with CCD? |
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Nesster
Joined: 24 Apr 2008
Posts: 5883
Location: NJ, USA
Expire: 2014-02-20
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| Posted: Thu Jul 01, 2010 3:52 pm Post subject: |
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Nesster wrote:
I think the cause is a flat rear element.
I have noted the blue glare, but only in specific situations - e.g. shooting camera photos against a bright white background. In most normal situations this isn't really a visible problem, at least in my experience.
I use a Pentax K100D
I'm confused about your intended use "snapping negatives" - does this mean you intend to use this for film dup work?
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lorriman
Joined: 16 May 2008
Posts: 34
Location: UK
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| Posted: Thu Jul 01, 2010 4:10 pm Post subject: |
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lorriman wrote:
| Nesster wrote: |
I think the cause is a flat rear element.
I have noted the blue glare, but only in specific situations - e.g. shooting camera photos against a bright white background. In most normal situations this isn't really a visible problem, at least in my experience.
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Yes I have seen these reports. A lot of my negatives have plenty of 'bright' bits as many of my pics involve significant dark parts, and this I believe will manifest the problem (along with a smaller aperture which is what I require).
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I use a Pentax K100D
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ccd?
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I'm confused about your intended use "snapping negatives" - does this mean you intend to use this for film dup work? |
Exactly. This is my hi-rez alternative to scanning. Currently I use a p&s (fuji F30 - renowned for resolution and ISO) for this purpose with its 5cm macro and it is fairy good, but I can't blow up beyond 7x6 without noticeable artifacts. |
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Nesster
Joined: 24 Apr 2008
Posts: 5883
Location: NJ, USA
Expire: 2014-02-20
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| Posted: Thu Jul 01, 2010 5:17 pm Post subject: |
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Nesster wrote:
I don't think you'll get into trouble with negative film - the brightest spots will be the shadows which all are orange masked.
An alternative path to consider is to get a slide duplication set - bellows, slide holder, and a 50mm or so lens. This gives you good precision and adjustability.
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lorriman
Joined: 16 May 2008
Posts: 34
Location: UK
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| Posted: Thu Jul 01, 2010 5:23 pm Post subject: |
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lorriman wrote:
| Nesster wrote: |
I don't think you'll get into trouble with negative film - the brightest spots will be the shadows which all are orange masked.
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Unfortunately to avoid noise reduction affecting the lighter areas one has to expose for maximum brightness and so I would expect this problem to manifest despite the orange mask.
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An alternative path to consider is to get a slide duplication set - bellows, slide holder, and a 50mm or so lens. This gives you good precision and adjustability. |
I have tried this but my experiments seemed to indicate I really need a proper macro lens if I am to get a decent lift in resolution and avoid flat-field problems. I'm rigging up a wooden device to give me the adjustability and precision (and dark box).
Thanks for the suggestions anyway. |
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visualopsins
Joined: 05 Mar 2009
Posts: 10543
Location: California
Expire: 2025-04-11
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| Posted: Thu Jul 01, 2010 5:31 pm Post subject: |
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visualopsins wrote:
| Nesster wrote: |
| I think the cause is a flat rear element. ... |
+1 both 52B and 52BB (I have both) produce central "bright spot" on images due to reflections between shiny flat rear element and shiny sensor, worse in some lighting situations than others. Film is much less reflective than are sensors.
90mm lens on crop camera for copying (entire 24x36mm) slides?
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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 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 (51BB), 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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lorriman
Joined: 16 May 2008
Posts: 34
Location: UK
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| Posted: Thu Jul 01, 2010 6:02 pm Post subject: |
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lorriman wrote:
| siriusdogstar wrote: |
| Nesster wrote: |
| I think the cause is a flat rear element. ... |
+1 both 52B and 52BB (I have both) produce central "bright spot" on images due to reflections between shiny flat rear element and shiny sensor, worse in some lighting situations than others. Film is much less reflective than are sensors.
90mm lens on crop camera for copying (entire 24x36mm) slides? |
Ordinary negs, actually. On a crop camera I believe I'll get the whole frame at 1:2. Am I wrong? |
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lorriman
Joined: 16 May 2008
Posts: 34
Location: UK
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| Posted: Thu Jul 01, 2010 8:14 pm Post subject: |
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lorriman wrote:
| siriusdogstar wrote: |
+1 both 52B and 52BB (I have both) produce central "bright spot" on images due to reflections between shiny flat rear element and shiny sensor, worse in some lighting situations than others. Film is much less reflective than are sensors.
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Sirius, what camera does this happen on? not the 450D by chance? |
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martinsmith99
Joined: 31 Aug 2008
Posts: 6943
Location: S Glos, UK
Expire: 2013-11-18
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| Posted: Thu Jul 01, 2010 8:22 pm Post subject: |
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martinsmith99 wrote:
I have yet to experience this on my Tamron 90 on either a 40D or 5D so I wouldn't worry just yet.
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ManualFocus-G
Joined: 29 Dec 2008
Posts: 6624
Location: United Kingdom
Expire: 2014-11-24
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| Posted: Thu Jul 01, 2010 8:31 pm Post subject: |
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ManualFocus-G wrote:
I experienced this with my 30D, 40D and 5D. Mostly when there was a bright light source behind the scene however. Point it at a lightbulb and you'll see it 
It was a very sharp lens, but I sold it once I acquired the Makro-Planar 
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Shooter of choice: Fujifilm X-T20 with M42, PB and C/Y lenses
See my Flickr photos at http://www.flickr.com/photos/manualfocus-g |
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lorriman
Joined: 16 May 2008
Posts: 34
Location: UK
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| Posted: Thu Jul 01, 2010 9:56 pm Post subject: |
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lorriman wrote:
Does anyone know if the 72B has this problem?
Does it also have a flat rear lens? |
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visualopsins
Joined: 05 Mar 2009
Posts: 10543
Location: California
Expire: 2025-04-11
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| Posted: Thu Jul 01, 2010 10:07 pm Post subject: |
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visualopsins wrote:
Canon XT (350D) and 5D1.
Iirc, there's no problem when 52B or 52BB 2.5/90 used with Tamron TCs, 1.4x and/or 2x. I haven't tried with the 1:1 extension tube; seems like that would be okay too, at least much better.
_________________
☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮ like attracts like! ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮
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 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 (51BB), 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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lorriman
Joined: 16 May 2008
Posts: 34
Location: UK
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| Posted: Thu Jul 01, 2010 11:07 pm Post subject: |
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lorriman wrote:
| siriusdogstar wrote: |
Canon XT (350D) and 5D1.
Iirc, there's no problem when 52B or 52BB 2.5/90 used with Tamron TCs, 1.4x and/or 2x. I haven't tried with the 1:1 extension tube; seems like that would be okay too, at least much better. |
Presumably only if you want it at 1:1 however. I need it at 1:2.
I assume that the extenders would not change the macro multiplier, so that might be a solution. Something of a pain though. I don't have one and I don;t really want the loss of resolution: this great plan of mine was supposed to maximise rez at lowest cost.
It's all going horribly wrong, unless the 450D has remarkable CMOS anti-reflection properties. |
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dnas
Joined: 14 Nov 2008
Posts: 488
Location: Japan
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| Posted: Fri Jul 02, 2010 3:16 am Post subject: |
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dnas wrote:
Here's what it looks like, for those who don't know(not taken on a 450D)
F8
F16
F32
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hinnerker
Joined: 17 Aug 2009
Posts: 929
Location: Germany near Kiel
Expire: 2015-08-09
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| Posted: Fri Jul 02, 2010 4:41 am Post subject: |
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hinnerker wrote:
Some months ago i did the same... on 5D...
This is a novoflex bellows with slide duplicator and a Noflexar 60mm/f4
It gives me 1:1 copys of the slide. The lightsource was a flashlight behind the
slidetray
To find out, what focal lenght works best for you, take a zoom instead of a 90mm...
IMHO 90mm should not work on the 450D. The Cropfactor 1.6 needs a wider angle of the lens. Maybe 35 or 40mm to get 1:1 Copies.
But if you want crop a part of the slide take a Noflexar 105mm for that bellows
Sometimes you can find that cheap on evilbay..
Cheers
Henry
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... and an EOS 5D MKII
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