If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Macro wide open - ??
On Fri, 01 Jun 2018 07:48:35 -0700, Whisky-dave
wrote in : On Friday, 1 June 2018 14:59:18 UTC+1, Paul Carmichael wrote: I'm sure this has been done to death before, but here goes... Why does my macro lens (Tamron SP90) open up to 2.5? Does it ? as it seems to state f2.8 on the web. It could be that the firmware of the camera has access to the lense T value in its database. PC uses a fairly modern EOS 6D mark II, IIRC. There is according to DxO Mark two different Tammies 90SP one T/3.0 and the other, newer T/3.3. The latter would be more like 2.5 rather than 2.8 if the former is used for reference... HTH! https://www.dxomark.com/lenses/brand...-between-1987- and-2018/mount_type-Canon_EF/focal-from-90-to-90/launch_price-from-0- to-13000-usd#hideAdvancedOptions=false&viewMode=list&yDataT ype=global -- teleportation kills |
#2
|
|||
|
|||
Macro wide open - ??
In article , android
wrote: Why does my macro lens (Tamron SP90) open up to 2.5? Does it ? as it seems to state f2.8 on the web. It could be that the firmware of the camera has access to the lense T value in its database. PC uses a fairly modern EOS 6D mark II, IIRC. There is according to DxO Mark two different Tammies 90SP one T/3.0 and the other, newer T/3.3. The latter would be more like 2.5 rather than 2.8 if the former is used for reference... HTH! or it could actually be f/2.5 http://www.adaptall-2.com/lenses/52B.html |
#3
|
|||
|
|||
Macro wide open - ??
|
#4
|
|||
|
|||
Macro wide open - ??
In article , android
wrote: Why does my macro lens (Tamron SP90) open up to 2.5? Does it ? as it seems to state f2.8 on the web. It could be that the firmware of the camera has access to the lense T value in its database. PC uses a fairly modern EOS 6D mark II, IIRC. There is according to DxO Mark two different Tammies 90SP one T/3.0 and the other, newer T/3.3. The latter would be more like 2.5 rather than 2.8 if the former is used for reference... HTH! or it could actually be f/2.5 http://www.adaptall-2.com/lenses/52B.html Sure. But that would not be reported from lense to camera. he didn't say it was reported to the camera. he only asked why it opens up to f/2.5, which is for a shallow depth of field and/or low light, like any other lens. |
#5
|
|||
|
|||
Macro wide open - ??
|
#6
|
|||
|
|||
Macro wide open - ??
In article , Paul Carmichael
wrote: or it could actually be f/2.5 http://www.adaptall-2.com/lenses/52B.html Sure. But that would not be reported from lense to camera. he didn't say it was reported to the camera. he only asked why it opens up to f/2.5, which is for a shallow depth of field and/or low light, like any other lens. Is low light ever an issue with macro photography? not usually, but that doesn't mean never. or, a fast shutter speed is desired, which would require a wide aperture (or crank the iso, but that adds noise). As for shallow depth of field, that's exactly what I'm saying. Wide open it won't get past a fly's eyeballs. So that's it then, some people like to take photos of fly's eyeballs. Seems a bit of a waste of glass to me. flies aren't the only macro subject. it could be something flat, like a postage stamp, where shallow dof doesn't matter much. |
#8
|
|||
|
|||
Macro wide open - ??
On Sat, 02 Jun 2018 10:01:22 +0200, Paul Carmichael
wrote in : On 01/06/18 19:09, android wrote: On Fri, 01 Jun 2018 18:33:36 +0200, Paul Carmichael wrote in : On 01/06/18 17:39, android wrote: On Fri, 01 Jun 2018 11:30:25 -0400, nospam wrote in lid: In article , android wrote: Why does my macro lens (Tamron SP90) open up to 2.5? Does it ? as it seems to state f2.8 on the web. It could be that the firmware of the camera has access to the lense T value in its database. PC uses a fairly modern EOS 6D mark II, IIRC. There is according to DxO Mark two different Tammies 90SP one T/3.0 and the other, newer T/3.3. The latter would be more like 2.5 rather than 2.8 if the former is used for reference... HTH! or it could actually be f/2.5 http://www.adaptall-2.com/lenses/52B.html Sure. But that would not be reported from lense to camera. I chipped the adaptall. So yes, it is. Then you would need to program the chip to report that that you want it to report... Well obviously. And knowing that the lens is 2.5-22, that's what I programmed it as. You were kind enough to post a link to a picture with the full exif, and it does not seem to be programmed at all: Make - Canon X-Resolution - 240 dpi Y-Resolution - 240 dpi Software - Adobe Photoshop Lightroom 6.14 (Windows) Date and Time (Modified) - 2018:06:02 11:57:16 Artist - PAUL CARMICHAEL Copyright - Paul Carmichael ISO Speed - 400 Sensitivity Type - Recommended Exposure Index Recommended Exposure Index - 400 Exif Version - 0230 Date and Time (Original) - 2018:06:01 14:07:22 Date and Time (Digitized) - 2018:06:01 14:07:22 Exposure Bias - 0 EV Max Aperture Value - 2.5 Metering Mode - Spot Sub Sec Time Original - 45 Sub Sec Time Digitized - 45 Color Space - sRGB Focal Plane X-Resolution - 1736.671661 Focal Plane Y-Resolution - 1736.671661 Focal Plane Resolution Unit - cm Custom Rendered - Normal Exposure Mode - Manual White Balance - Auto Scene Capture Type - Standard Lens Info - 1-65535mm f/? Lens Model - 1-65535mm Lens Serial Number - 0000000000 Compression - JPEG (old-style) Thumbnail Offset - 924 Thumbnail Length - 9204 Displayed Units X - inches Displayed Units Y - inches Photoshop Thumbnail - (Binary data 9204 bytes, use -b option to extract) IPTCDigest - da8e5702bcc8319be00c7ea61cbf483c Coded Character Set - UTF8 Application Record Version - 4 Date Created - 2018:06:01 Time Created - 14:07:22 Digital Creation Date - 2018:06:01 Digital Creation Time - 14:07:22 By-line - PAUL CARMICHAEL Copyright Notice - Paul Carmichael Viewing Cond Illuminant - 19.6445 20.3718 16.8089 Viewing Cond Surround - 3.92889 4.07439 3.36179 Viewing Conditions Illuminant Type - D50 Measurement Observer - CIE 1931 Measurement Backing - 0 0 0 Measurement Geometry - Unknown (0) Measurement Flare - 0.999% Measurement Illuminant - D65 XMPToolkit - Adobe XMP Core 5.6-c128 79.159124, 2016/03/18-14:01:55 Creator Tool - Adobe Photoshop Lightroom 6.14 (Windows) Metadata Date - 2018:06:02 11:57:16+02:00 Format - image/jpeg Creator - PAUL CARMICHAEL Rights - Paul Carmichael Lens ID - 27 Image Number - 0 Flash Compensation - 0 Firmware - 1.0.3 Document ID - xmp.did:05a22f79-0fc0-2346-9f19-9bc9f898e189 Original Document ID - 4F1C3E75149E495551660044089B79B5 Instance ID - xmp.iid:05a22f79-0fc0-2346-9f19-9bc9f898e189 History Action - derived History Parameters - converted from image/x-canon-cr2 to image/jpeg, saved to new location History Instance ID - xmp.iid:05a22f79-0fc0-2346-9f19-9bc9f898e189 History When - 2018:06:02 11:57:16+02:00 History Software Agent - Adobe Photoshop Lightroom 6.14 (Windows) History Changed - / Derived From Document ID - 4F1C3E75149E495551660044089B79B5 Derived From Original Document ID - 4F1C3E75149E495551660044089B79B5 DCTEncode Version - 100 APP14 Flags0 - [14], Encoded with Blend=1 downsampling APP14 Flags1 - (none) Color Transform - YCbCr Camera ID - 72157662779818774 Camera Type - Digital SLR https://www.flickr.com/photos/wibble...in/dateposted- family/ -- teleportation kills |
#9
|
|||
|
|||
Macro wide open - ??
On Sun, 03 Jun 2018 13:42:02 +0200, Paul Carmichael
wrote in : On 03/06/18 06:01, android wrote: On Sat, 02 Jun 2018 10:01:22 +0200, Paul Carmichael wrote in : On 01/06/18 19:09, android wrote: On Fri, 01 Jun 2018 18:33:36 +0200, Paul Carmichael wrote in : On 01/06/18 17:39, android wrote: On Fri, 01 Jun 2018 11:30:25 -0400, nospam wrote in lid: In article , android wrote: Why does my macro lens (Tamron SP90) open up to 2.5? Does it ? as it seems to state f2.8 on the web. It could be that the firmware of the camera has access to the lense T value in its database. PC uses a fairly modern EOS 6D mark II, IIRC. There is according to DxO Mark two different Tammies 90SP one T/3.0 and the other, newer T/3.3. The latter would be more like 2.5 rather than 2.8 if the former is used for reference... HTH! or it could actually be f/2.5 http://www.adaptall-2.com/lenses/52B.html Sure. But that would not be reported from lense to camera. I chipped the adaptall. So yes, it is. Then you would need to program the chip to report that that you want it to report... Well obviously. And knowing that the lens is 2.5-22, that's what I programmed it as. You were kind enough to post a link to a picture with the full exif, and it does not seem to be programmed at all: I don't get your point. Do you know how these chips work? The chip tells the camera that it's a 90mm lens. I have to tell the camera the aperture setting. It won't let me go below 2.5 or over 22 (I "programmed" the chip to know it's a 90mm lens with aperture between 2.5 and 22). What I tell the camera is what's reported in the exif. Obviously the chip can't know what I've set the aperture to. Also, the chip enables focus confirmation. They are generally sold as "focus confirmation chips". Exif: Max Aperture Value - 2.5 Oki... "Capture Type - Standard Lens Info - 1-65535mm f/? Lens Model - 1-65535mm Lens Serial Number - 0000000000 Compression - JPEG (old-style)" Not a very complete programing then... And you complaint against your lense was? -- teleportation kills |
#10
|
|||
|
|||
Macro wide open - ??
On Sun, 03 Jun 2018 15:36:12 +0200, Paul Carmichael
wrote in : On 03/06/18 15:27, android wrote: On Sun, 03 Jun 2018 13:42:02 +0200, Paul Carmichael wrote in : On 03/06/18 06:01, android wrote: On Sat, 02 Jun 2018 10:01:22 +0200, Paul Carmichael wrote in : On 01/06/18 19:09, android wrote: On Fri, 01 Jun 2018 18:33:36 +0200, Paul Carmichael wrote in : On 01/06/18 17:39, android wrote: On Fri, 01 Jun 2018 11:30:25 -0400, nospam wrote in lid: In article , android wrote: Why does my macro lens (Tamron SP90) open up to 2.5? Does it ? as it seems to state f2.8 on the web. It could be that the firmware of the camera has access to the lense T value in its database. PC uses a fairly modern EOS 6D mark II, IIRC. There is according to DxO Mark two different Tammies 90SP one T/3.0 and the other, newer T/3.3. The latter would be more like 2.5 rather than 2.8 if the former is used for reference... HTH! or it could actually be f/2.5 http://www.adaptall-2.com/lenses/52B.html Sure. But that would not be reported from lense to camera. I chipped the adaptall. So yes, it is. Then you would need to program the chip to report that that you want it to report... Well obviously. And knowing that the lens is 2.5-22, that's what I programmed it as. You were kind enough to post a link to a picture with the full exif, and it does not seem to be programmed at all: I don't get your point. Do you know how these chips work? The chip tells the camera that it's a 90mm lens. I have to tell the camera the aperture setting. It won't let me go below 2.5 or over 22 (I "programmed" the chip to know it's a 90mm lens with aperture between 2.5 and 22). What I tell the camera is what's reported in the exif. Obviously the chip can't know what I've set the aperture to. Also, the chip enables focus confirmation. They are generally sold as "focus confirmation chips". Exif: Max Aperture Value - 2.5 Oki... "Capture Type - Standard Lens Info - 1-65535mm f/? Lens Model - 1-65535mm Lens Serial Number - 0000000000 Compression - JPEG (old-style)" Not a very complete programing then... And you complaint against your lense was? What is is with you? Did you not read what I wrote? Sure did. You can't take the heat well, do ya? And what complaint are you talking about? This one: On Fri, 01 Jun 2018 15:59:10 +0200, Paul Carmichael wrote in : I'm sure this has been done to death before, but here goes... Why does my macro lens (Tamron SP90) open up to 2.5? So it's made that way! Unless it's to take photos of a molecule, what's the point? With your lense? I does focus beyond 5cm don't it? The last question was rhetorical... https://en.wiktionary.org/wiki/rhetorical_question#English -- teleportation kills |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
[SI] Wide Open is now open for viewing | bowser | 35mm Photo Equipment | 3 | March 9th 09 11:43 AM |
[SI]: New Mandate: Wide Open | bowser | Digital Photography | 22 | February 14th 09 08:44 PM |
[SI]: New Mandate: Wide Open | bowser | Digital SLR Cameras | 22 | February 14th 09 08:44 PM |
DSLR lenses not good wide open at wide angle? | Alfred Molon[_4_] | Digital Photography | 7 | July 16th 08 01:29 PM |
Canon efs 60mm f2.8 macro underexposure wide-open | Geoffrey | Digital Photography | 0 | October 11th 06 11:57 AM |