Is the 50mm A1.7 faster than F1.7?

paperbag846 · 10-27-2010, 10:14 AM

Originally posted by ramair455

I have a 28 that has beautiful bokeh....

Maybe I was too hard on the bokeh... I think the bokeh is great for a wide angle. However it does not blur nearly as much as a 50mm, simply due to the focal length. While I'm still not sure what is bothering him so much, I still think that he is noticing the benefit of a longer focal length w.r.t subject/background seperation, which is much more challenging to do with a wide angle lens.

I still think, in many ways, that the "problems" he is noticing with the DA 21mm is simply what you get with a wide angle lens, which is why it is good to own both. There are certainly many pictures I can think of that are just impossible to capture with a 50mm, and the 21 is the perfect compliment to that (IMHO).

Now he is talking about gamma... where I would start to wonder if he should look at the "camera calibration" section of lightroom. The camera you have will adjust settings for the DA 21, but won't for the A 50 because there is no chip inside that lens. Therefore, you might simply prefer the default camera calibration over the optimized one for the DA 21?

troglodyte · 10-27-2010, 12:40 PM

Paperbag,
How do you make the k-7 act like the A50 inside the camera? I have test equipment for gamma curves, like video processors, caliberated crt monitor, etc. I never thought to check. I just assumed a standard gamma but gamma is very very low so that

troglodyte · 10-27-2010, 12:45 PM

on my PC LCD colors look muddy and not vibrant which has a much higher gamma. Seems odd that the camera would 'optimize' such a low gamma curve.
Normally for pictures I just expose, snap adjust exposure and sharpness in LR. All is fine with the A50mm

troglodyte · 10-27-2010, 12:47 PM

doing that. I don't have to adjust curves like this.

**Lowell Goudge** · 10-27-2010, 12:50 PM

how about a photo

it is hard to imagine the issue without seeing it.

paperbag846 · 10-27-2010, 01:13 PM

1) In lightroom, you could save a preset with just the gamma curve. This preset could be named "DA 21 Gamma" and you could use it to quickly adjust the gamma of all your DA 21 photos fairly quickly.

2) Look under camera calibration in "develop" and fool around. There are no settings in the camera... rather, you want to adjust how Lightroom interprets the information out of the camera. It would be easier for you to learn how this feature works yourself by fooling around.

I've never had a real issue although it is clear to me that every lens I own adds its own colour hue and contrast to the mix. I tend to take it one by one, but I love post-processing (probably
"over fix" my photos if anything). This is just something I get used to, and I kind of like it.

For example, my A 28 2.8 tends to be a little more neutral colour wise, which can be very calm or film-like. My K 55 1.8 tends to be very soft and muted - great for portraits. My A 50 1.7 tends to be a fireball - super saturated and contrast heavy - great for photos that POP. It's really down to the individual lens.

It adds another dimension to choosing the right prime outside of focal length and aperture. However, if you correct the DA 21 to look like the A 50 1.7 and like it that way, save those changes as a preset and you will be able to make any photo you want look like the A 50, with the advantage of the wider focal length.

Make sure when you save your preset to only save the things you want changed for every photo - likely the gamma curve, but not white balance. Make sense?

troglodyte · 10-28-2010, 12:14 AM

paperbag,
I tried what you said but there just wasn't quite enough options. So I instead loaded a A50 photo and manipulated a few da21 photos until I had a preset which worked at .66 exposure as a starting point so I could auto tone and back to my preset

troglodyte · 10-28-2010, 12:17 AM

a happy medium was reached. I don't like doing post much. My 50mm requires almost none, while the da21 is a fussy child!

troglodyte · 10-28-2010, 12:22 AM

Hey all,
I'd post examples till you'd bleed if you so desire. I'm on a cell that limits text as is. I finally found out why each post is limited on an 'unlimited' plan. It's because unlimited doesn't mean unreasonable! But as soon as I can get on a real

troglodyte · 10-28-2010, 12:23 AM

computer I will upload tons and you'll all probably wish you didn't ask!

paperbag846 · 10-28-2010, 06:47 AM

Trog,

I'm confused, you can save a preset with the "tone curve" which is your gamma. Any option you can set, can be saved as a preset. So if the gamma response is different between lenses, this would be the way to fix it.

Remember, everything is subjective. Some people like strong contrast, some people like a soft curve. My friend likes to make his digital images look like film by adjusting the darks up, to make it look more like vintage film. In his words "The problem is, digital just looks too GOOD".

egordon99 · 10-28-2010, 09:43 AM

Originally posted by troglodyte

So would getting a medium format camera allow me to use a 50mm lens with the light properties ie DOF, isolation, etc but gain the angle of view I want? 21mm on aps-c and 35mm on FF?

Not the SMC-A 50mm f/1.7 as I doubt it casts a large enough image circle for medium format film.

egordon99 · 10-28-2010, 09:47 AM

Originally posted by paperbag846

Considering you want a fast-as-possible wide angle, increasing the sensor size will help, but is becoming less necessary as technology improves. You will get thinner DOF's because you will be able to stand closer to your subjects with the same focal length.

Changing your position changes the perspective, which changes the "look" of the image.

The general "thought" that yields "Full frame has shallower depth-of-field" has to do with requiring a LONGER focal length on FF to achieve the same framing AND perspective compared to crop.

As an example, I love my Sigma 30mm f/1.4 on my crop bodies. I get very shallow DOF @ f/1.4. Now I want even shallower DOF, but want to retain the same framing and perspective. I mount a 45mm f/1.4 on a FILM camera (or digital FF, whatever...) and retain my position. The DOF is shallower because the absolute aperture is bigger with the 45mm compared to the 30mm, even though both are f/1.4.

egordon99 · 10-28-2010, 09:49 AM

Originally posted by paperbag846

See what you did here? f4 at 21mm does not equal f4 at 50mm. Thats why you should do the test that Lowell suggested to figure out how each lens exposes.

But they SHOULD be close. Otherwise external (incident) light meters would NOT work.

Using the f/ notation takes the focal length out of the "equation". Otherwise you would just use absolute aperture. "Yeah, I'm shooting my 50mm at an aperture of 25mm. To retain my exposure with my 30mm, I'll need to shoot at an aperture of 15mm."

Using f/2 makes much more sense when talking about aperture in regards to exposure.

egordon99 · 10-28-2010, 09:52 AM

Originally posted by troglodyte

'optimized for digital'. The A lens doesn't do this crap and is decades older with no fancy stuff. I shouldn't have to dissect images like this.

No, you shouldn't need to disect anything. Just go out and shoot! Concentrate on the lighting, composition, and exposure, and not any teeny tiny differences in "rendering"/whatever.

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10-27-2010, 10:14 AM	#61
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395	Originally posted by ramair455 I have a 28 that has beautiful bokeh.... Maybe I was too hard on the bokeh... I think the bokeh is great for a wide angle. However it does not blur nearly as much as a 50mm, simply due to the focal length. While I'm still not sure what is bothering him so much, I still think that he is noticing the benefit of a longer focal length w.r.t subject/background seperation, which is much more challenging to do with a wide angle lens. I still think, in many ways, that the "problems" he is noticing with the DA 21mm is simply what you get with a wide angle lens, which is why it is good to own both. There are certainly many pictures I can think of that are just impossible to capture with a 50mm, and the 21 is the perfect compliment to that (IMHO). Now he is talking about gamma... where I would start to wonder if he should look at the "camera calibration" section of lightroom. The camera you have will adjust settings for the DA 21, but won't for the A 50 because there is no chip inside that lens. Therefore, you might simply prefer the default camera calibration over the optimized one for the DA 21?

10-27-2010, 12:40 PM	#62
troglodyte Veteran Member Join Date: Jul 2010 Location: Oz Posts: 408 Original Poster	Paperbag, How do you make the k-7 act like the A50 inside the camera? I have test equipment for gamma curves, like video processors, caliberated crt monitor, etc. I never thought to check. I just assumed a standard gamma but gamma is very very low so that

10-27-2010, 12:45 PM	#63
troglodyte Veteran Member Join Date: Jul 2010 Location: Oz Posts: 408 Original Poster	on my PC LCD colors look muddy and not vibrant which has a much higher gamma. Seems odd that the camera would 'optimize' such a low gamma curve. Normally for pictures I just expose, snap adjust exposure and sharpness in LR. All is fine with the A50mm

10-27-2010, 12:47 PM	#64
troglodyte Veteran Member Join Date: Jul 2010 Location: Oz Posts: 408 Original Poster	doing that. I don't have to adjust curves like this.

10-27-2010, 12:50 PM	#65
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,886	how about a photo it is hard to imagine the issue without seeing it.

10-27-2010, 01:13 PM	#66
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395	1) In lightroom, you could save a preset with just the gamma curve. This preset could be named "DA 21 Gamma" and you could use it to quickly adjust the gamma of all your DA 21 photos fairly quickly. 2) Look under camera calibration in "develop" and fool around. There are no settings in the camera... rather, you want to adjust how Lightroom interprets the information out of the camera. It would be easier for you to learn how this feature works yourself by fooling around. I've never had a real issue although it is clear to me that every lens I own adds its own colour hue and contrast to the mix. I tend to take it one by one, but I love post-processing (probably "over fix" my photos if anything). This is just something I get used to, and I kind of like it. For example, my A 28 2.8 tends to be a little more neutral colour wise, which can be very calm or film-like. My K 55 1.8 tends to be very soft and muted - great for portraits. My A 50 1.7 tends to be a fireball - super saturated and contrast heavy - great for photos that POP. It's really down to the individual lens. It adds another dimension to choosing the right prime outside of focal length and aperture. However, if you correct the DA 21 to look like the A 50 1.7 and like it that way, save those changes as a preset and you will be able to make any photo you want look like the A 50, with the advantage of the wider focal length. Make sure when you save your preset to only save the things you want changed for every photo - likely the gamma curve, but not white balance. Make sense?

10-28-2010, 12:14 AM	#67
troglodyte Veteran Member Join Date: Jul 2010 Location: Oz Posts: 408 Original Poster	paperbag, I tried what you said but there just wasn't quite enough options. So I instead loaded a A50 photo and manipulated a few da21 photos until I had a preset which worked at .66 exposure as a starting point so I could auto tone and back to my preset

10-28-2010, 12:17 AM	#68
troglodyte Veteran Member Join Date: Jul 2010 Location: Oz Posts: 408 Original Poster	a happy medium was reached. I don't like doing post much. My 50mm requires almost none, while the da21 is a fussy child!

10-28-2010, 12:22 AM	#69
troglodyte Veteran Member Join Date: Jul 2010 Location: Oz Posts: 408 Original Poster	Hey all, I'd post examples till you'd bleed if you so desire. I'm on a cell that limits text as is. I finally found out why each post is limited on an 'unlimited' plan. It's because unlimited doesn't mean unreasonable! But as soon as I can get on a real

10-28-2010, 12:23 AM	#70
troglodyte Veteran Member Join Date: Jul 2010 Location: Oz Posts: 408 Original Poster	computer I will upload tons and you'll all probably wish you didn't ask!

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10-28-2010, 06:47 AM	#71
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395	Trog, I'm confused, you can save a preset with the "tone curve" which is your gamma. Any option you can set, can be saved as a preset. So if the gamma response is different between lenses, this would be the way to fix it. Remember, everything is subjective. Some people like strong contrast, some people like a soft curve. My friend likes to make his digital images look like film by adjusting the darks up, to make it look more like vintage film. In his words "The problem is, digital just looks too GOOD".

10-28-2010, 09:43 AM	#72
egordon99 Inactive Account Join Date: Dec 2006 Location: Outside of Philly Posts: 1,561	Originally posted by troglodyte So would getting a medium format camera allow me to use a 50mm lens with the light properties ie DOF, isolation, etc but gain the angle of view I want? 21mm on aps-c and 35mm on FF? Not the SMC-A 50mm f/1.7 as I doubt it casts a large enough image circle for medium format film.

10-28-2010, 09:47 AM	#73
egordon99 Inactive Account Join Date: Dec 2006 Location: Outside of Philly Posts: 1,561	Originally posted by paperbag846 Considering you want a fast-as-possible wide angle, increasing the sensor size will help, but is becoming less necessary as technology improves. You will get thinner DOF's because you will be able to stand closer to your subjects with the same focal length. Changing your position changes the perspective, which changes the "look" of the image. The general "thought" that yields "Full frame has shallower depth-of-field" has to do with requiring a LONGER focal length on FF to achieve the same framing AND perspective compared to crop. As an example, I love my Sigma 30mm f/1.4 on my crop bodies. I get very shallow DOF @ f/1.4. Now I want even shallower DOF, but want to retain the same framing and perspective. I mount a 45mm f/1.4 on a FILM camera (or digital FF, whatever...) and retain my position. The DOF is shallower because the absolute aperture is bigger with the 45mm compared to the 30mm, even though both are f/1.4.

10-28-2010, 09:49 AM	#74
egordon99 Inactive Account Join Date: Dec 2006 Location: Outside of Philly Posts: 1,561	Originally posted by paperbag846 See what you did here? f4 at 21mm does not equal f4 at 50mm. Thats why you should do the test that Lowell suggested to figure out how each lens exposes. But they SHOULD be close. Otherwise external (incident) light meters would NOT work. Using the f/ notation takes the focal length out of the "equation". Otherwise you would just use absolute aperture. "Yeah, I'm shooting my 50mm at an aperture of 25mm. To retain my exposure with my 30mm, I'll need to shoot at an aperture of 15mm." Using f/2 makes much more sense when talking about aperture in regards to exposure.

10-28-2010, 09:52 AM	#75
egordon99 Inactive Account Join Date: Dec 2006 Location: Outside of Philly Posts: 1,561	Originally posted by troglodyte 'optimized for digital'. The A lens doesn't do this crap and is decades older with no fancy stuff. I shouldn't have to dissect images like this. No, you shouldn't need to disect anything. Just go out and shoot! Concentrate on the lighting, composition, and exposure, and not any teeny tiny differences in "rendering"/whatever.