Thematic Post your Exclusive Gallery Rejects

**Ash** · 04-21-2011, 08:25 PM

With the luxury of focus stacking Tanner, there is never the need for anything more than f/8. So you're definitely justified there. The above shot was between 1:1.1 and 1:1, so effectively it would have been life-size, hence the thin DoF.

I take your point though - I have no doubt there will be diffractive degradation of IQ at anything smaller than f/8, and it's all the more magnified with the use of extension tubes and lens reversing. I appreciate that, and that's why I leave such extreme macro work to budding masters as yourself, and just stick to 1:1 or less myself.

**BigDave** · 04-21-2011, 09:27 PM

Yeatzee:

I understand the calculations for the higher effective f-numbers, this is due to the inverse square law (bellows factor) coming into play. But diffraction is not dependent on the effective f-number, only the actual f-number used at the lens. The effective f number is just used to calculate the proper exposure under the given lighting situation. Given enough distance between the lens and image plain, you can get an f1.8 lens, wide open, to give an effective f-number of f72 or 90. OK, we are talking about a LOOONGGG bellows distance then, but diffraction would not come into play at this wide aperture. THis is what my research has indicated.

yeatzee · 04-21-2011, 10:27 PM

Originally posted by BigDave

Yeatzee:

I understand the calculations for the higher effective f-numbers, this is due to the inverse square law (bellows factor) coming into play. But diffraction is not dependent on the effective f-number, only the actual f-number used at the lens. The effective f number is just used to calculate the proper exposure under the given lighting situation. Given enough distance between the lens and image plain, you can get an f1.8 lens, wide open, to give an effective f-number of f72 or 90. OK, we are talking about a LOOONGGG bellows distance then, but diffraction would not come into play at this wide aperture. THis is what my research has indicated.

my point still holds true

**Ash** · 04-29-2011, 02:12 PM

And one more for this collection - only comment was for the distracting dark spot created by a leaf that was in the way. Can't argue with that:

Rhesus macaque

Class A · 04-29-2011, 05:42 PM

Originally posted by Ash

But what lens/setup are you using that produces this level of haze?
I've looked at my images at 100% and even at f/22 my FA 100 macro is very sharp.

Ash, Tanner is right, one should best avoid high f-ratios. It is not a matter of lenses, the diffraction effects simply reduce the resolution.

Look at Table 3 of this "Sensors outresolved by lenses?" article. On APS-C, an f-ratio of f/22 leaves with the equivalent of 2MP resolution, independently of how high your sensor resolves.

Tanner, your "saluting spider" is a cracker shot! Congrats! As for PEG rejecting it: No comment.

**Ash** · 04-30-2011, 03:29 AM

Originally posted by Class A

Look at Table 3 of this "Sensors outresolved by lenses?" article. On APS-C, an f-ratio of f/22 leaves with the equivalent of 2MP resolution, independently of how high your sensor resolves.

I had a look at the table and I'm sure it applies to most lenses, and I wouldn't bother shooting at f/22 with most other lenses, but the macro lenses retain a lot more detail at those smaller f-ratios than other lenses.

I'm not all that convinced that a 16Mp image at f/22 with my FA 100 macro would have the equivalent resolution of 2Mp. I see far more detail than that on my images.

Class A · 04-30-2011, 05:46 AM

Originally posted by Ash

I had a look at the table and I'm sure it applies to most lenses, and I wouldn't bother shooting at f/22 with most other lenses, but the macro lenses retain a lot more detail at those smaller f-ratios than other lenses.

I see no reason why they should.

Maybe because they show more detail to begin with, it looks as if they retained more, but the article clearly talks about diffraction in a lens-independent way and, again, I cannot think of any reason as to why a macro lens would make any difference to the physics.

JeffJS · 05-22-2011, 06:50 PM

Exif | K5JS6131_mDFA100_May21_2011 | Flickr - Photo Sharing!

FB..

Nice lighting and background control, but uninteresting and awkwardly aligned central composition with cropping of features above and below that form part of the subject. The thin DoF has also caused the front of the subject to be out of focus.

I guess I can agree for the most part but I don't know how to add interest to a shot like this (uncropped) when the entire shot is bokeh. That is, what difference would the position in the frame make? The only thing I could really guess at is a Portrait orientation.

thoughton · 05-23-2011, 02:37 AM

Originally posted by JeffJS

That is, what difference would the position in the frame make? The only thing I could really guess at is a Portrait orientation.

No offense Jeff, but that is basic Composition 101! Central subject = bad, off-center subject = good

Obviously this is a rule of thumb, but for most situations it works.

JeffJS · 05-23-2011, 06:49 AM

Originally posted by thoughton

No offense Jeff, but that is basic Composition 101! Central subject = bad, off-center subject = good

Obviously this is a rule of thumb, but for most situations it works.

Except it isn't centered. There is more open space on the left than there is on the right.

**BigDave** · 05-23-2011, 04:37 PM

Yes Jeff, there is, but ever so slightly. This composition would have worked much better in the vertical/portrait format, and with the bud/stem on the left or right third of the frame. And the comment about the DoF is valid. You need more of it, especially giving sharpness in the front, where the viewer would expect to see it. You probably would not have suffered any Bokeh reduction either.

Regards,

JeffJS · 05-23-2011, 05:00 PM

I know... I'm just nitpicking a little bit

After taking a few more looks at it, it isn't as sharp as it could have been.

photolady95 · 05-23-2011, 07:13 PM

Tried again did you? Me too. We'll see it this one gets through. I've have three that were rejected there but approved in that other gallery.

JeffJS · 05-23-2011, 07:26 PM

Actually I've tried several times. I've just been blasting them out of the regular galleries and haven't been putting anything here. I see which 3 you are referring to in your PPG. One of them WAS in the PEG but then bounced. I see Mr Eagle made it in too. Good show!

photolady95 · 05-24-2011, 07:01 AM

Well, another PEG bites the dust:

And there was no comments as to why. Well, it's in PPG for approval now, so I'll wait and hope on that gallery.

Thanks Jeff. I was happy when the eagle got in PPG as well as the others, I just wish I could get one in PEG as well. I've seen some accepted in there that I consider should have been rejected toot sweet. LOL

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04-21-2011, 08:25 PM	#331
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	With the luxury of focus stacking Tanner, there is never the need for anything more than f/8. So you're definitely justified there. The above shot was between 1:1.1 and 1:1, so effectively it would have been life-size, hence the thin DoF. I take your point though - I have no doubt there will be diffractive degradation of IQ at anything smaller than f/8, and it's all the more magnified with the use of extension tubes and lens reversing. I appreciate that, and that's why I leave such extreme macro work to budding masters as yourself, and just stick to 1:1 or less myself.

04-21-2011, 09:27 PM	#332
BigDave Site Supporter Join Date: Sep 2010 Location: Hudson Valley, NY Photos: Gallery \| Albums Posts: 2,626	Yeatzee: I understand the calculations for the higher effective f-numbers, this is due to the inverse square law (bellows factor) coming into play. But diffraction is not dependent on the effective f-number, only the actual f-number used at the lens. The effective f number is just used to calculate the proper exposure under the given lighting situation. Given enough distance between the lens and image plain, you can get an f1.8 lens, wide open, to give an effective f-number of f72 or 90. OK, we are talking about a LOOONGGG bellows distance then, but diffraction would not come into play at this wide aperture. THis is what my research has indicated.

04-21-2011, 10:27 PM	#333
yeatzee Veteran Member Join Date: Feb 2009 Location: Temecula Photos: Gallery \| Albums Posts: 3,675	Originally posted by BigDave Yeatzee: I understand the calculations for the higher effective f-numbers, this is due to the inverse square law (bellows factor) coming into play. But diffraction is not dependent on the effective f-number, only the actual f-number used at the lens. The effective f number is just used to calculate the proper exposure under the given lighting situation. Given enough distance between the lens and image plain, you can get an f1.8 lens, wide open, to give an effective f-number of f72 or 90. OK, we are talking about a LOOONGGG bellows distance then, but diffraction would not come into play at this wide aperture. THis is what my research has indicated. my point still holds true

04-29-2011, 02:12 PM	#334
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	And one more for this collection - only comment was for the distracting dark spot created by a leaf that was in the way. Can't argue with that: Rhesus macaque

04-29-2011, 05:42 PM	#335
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by Ash But what lens/setup are you using that produces this level of haze? I've looked at my images at 100% and even at f/22 my FA 100 macro is very sharp. Ash, Tanner is right, one should best avoid high f-ratios. It is not a matter of lenses, the diffraction effects simply reduce the resolution. Look at Table 3 of this "Sensors outresolved by lenses?" article. On APS-C, an f-ratio of f/22 leaves with the equivalent of 2MP resolution, independently of how high your sensor resolves. Tanner, your "saluting spider" is a cracker shot! Congrats! As for PEG rejecting it: No comment.

04-30-2011, 03:29 AM	#336
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Originally posted by Class A Look at Table 3 of this "Sensors outresolved by lenses?" article. On APS-C, an f-ratio of f/22 leaves with the equivalent of 2MP resolution, independently of how high your sensor resolves. I had a look at the table and I'm sure it applies to most lenses, and I wouldn't bother shooting at f/22 with most other lenses, but the macro lenses retain a lot more detail at those smaller f-ratios than other lenses. I'm not all that convinced that a 16Mp image at f/22 with my FA 100 macro would have the equivalent resolution of 2Mp. I see far more detail than that on my images.

04-30-2011, 05:46 AM	#337
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by Ash I had a look at the table and I'm sure it applies to most lenses, and I wouldn't bother shooting at f/22 with most other lenses, but the macro lenses retain a lot more detail at those smaller f-ratios than other lenses. I see no reason why they should. Maybe because they show more detail to begin with, it looks as if they retained more, but the article clearly talks about diffraction in a lens-independent way and, again, I cannot think of any reason as to why a macro lens would make any difference to the physics.

05-22-2011, 06:50 PM	#338
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Exif \| K5JS6131_mDFA100_May21_2011 \| Flickr - Photo Sharing! FB.. Nice lighting and background control, but uninteresting and awkwardly aligned central composition with cropping of features above and below that form part of the subject. The thin DoF has also caused the front of the subject to be out of focus. I guess I can agree for the most part but I don't know how to add interest to a shot like this (uncropped) when the entire shot is bokeh. That is, what difference would the position in the frame make? The only thing I could really guess at is a Portrait orientation.

05-23-2011, 02:37 AM	#339
thoughton Veteran Member Join Date: Jul 2009 Location: Saffron Walden, Essex Photos: Gallery Posts: 362	Originally posted by JeffJS That is, what difference would the position in the frame make? The only thing I could really guess at is a Portrait orientation. No offense Jeff, but that is basic Composition 101! Central subject = bad, off-center subject = good Obviously this is a rule of thumb, but for most situations it works.

05-23-2011, 06:49 AM	#340
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Originally posted by thoughton No offense Jeff, but that is basic Composition 101! Central subject = bad, off-center subject = good Obviously this is a rule of thumb, but for most situations it works. Except it isn't centered. There is more open space on the left than there is on the right.

05-23-2011, 04:37 PM	#341
BigDave Site Supporter Join Date: Sep 2010 Location: Hudson Valley, NY Photos: Gallery \| Albums Posts: 2,626	Yes Jeff, there is, but ever so slightly. This composition would have worked much better in the vertical/portrait format, and with the bud/stem on the left or right third of the frame. And the comment about the DoF is valid. You need more of it, especially giving sharpness in the front, where the viewer would expect to see it. You probably would not have suffered any Bokeh reduction either. Regards,

05-23-2011, 05:00 PM	#342
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	I know... I'm just nitpicking a little bit After taking a few more looks at it, it isn't as sharp as it could have been.

05-23-2011, 07:13 PM	#343
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	Tried again did you? Me too. We'll see it this one gets through. I've have three that were rejected there but approved in that other gallery.

05-23-2011, 07:26 PM	#344
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Actually I've tried several times. I've just been blasting them out of the regular galleries and haven't been putting anything here. I see which 3 you are referring to in your PPG. One of them WAS in the PEG but then bounced. I see Mr Eagle made it in too. Good show!

05-24-2011, 07:01 AM	#345
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	Well, another PEG bites the dust: And there was no comments as to why. Well, it's in PPG for approval now, so I'll wait and hope on that gallery. Thanks Jeff. I was happy when the eagle got in PPG as well as the others, I just wish I could get one in PEG as well. I've seen some accepted in there that I consider should have been rejected toot sweet. LOL