Tagged with chart - Personal View Talks

50mm lenses, fast ones

Tesselator — Mon, 11 Jul 2011 03:12:30 +0000

I thought there was a thread on this already but I can't seen to locate it. I guess it could have been on another site tho... Anyway I recently compared 10 "normals" with apertures larger than 2.0 in a 1m res-chart test and thought in might be useful to post up.

During the shooting of the Takumar I caught some specular reflections. I recently built an automatic indoor bird bath for my parrot and it's got a little lightshow that goes off every time it turns on. Those lights showed up in the test chart without me noticing - and I'm way too lazy to reshoot. :D

These were all done on the 1m chart at ISO 100, with AE turned on. WB was set to the chart's white looking through the Canon FD 50/1.4 SSC and left there so the color differences (for white at least) could be compared. I only included the right and left corners cuz that's pretty much mid-area if shot on a FF anyway (not center, but mid).

This test obviously won't tell everything about a lens like how sharp it is when focused to infinity or what the bokeh is like, but I guess it's a pretty good comparison for these to show sharpness at one meter. And 1 to 3 meters is nice bust portraiture with a 50mm on the GH1.

The chart numbers are to be multiplied by 100 to get LPP (Lines Per Picture). But actually, since I was pulled out just a tad in order to use the box for framing the shots, maybe multiplying by 107 or so would be more accurate. :D I shot them all in 4x3 format on a Linhof tripod, with the 10s timer, using the 15X zoom MF assist - using the right-most red box (above) as the focus point.

The Canons seem to be the winners (in this test) but all of those are IMO excellent lenses - except the Rokkor-PF F/1.7 maybe. And it's an awesome looking antique. I have a bunch of other 50's that start at 2.0 or greater which are also very wonderful - like the 55/2.8 Nikkor Micro, the Minolta AF 50/2.8 Marco or some of the Zeiss/Jena Biotars and various Tessar implementations, etc..

I also wanted to test the Voigtlander 50/1.5 but I can't seem to find my adapter.

Cheap ColorChecker chart alternative

Vitaliy_Kiselev — Mon, 30 Jan 2017 04:40:14 +0000

ColorChecker like colors
24 colors
21.5cm x 14.7cm
Package weight - 146g
$19 only including shipping

Note - do not use ColorChecker references for this, but for matching shots across different takes, places or cameras it works perfect.

https://www.aliexpress.com/item/Professional-24-Color-Card-Test-Color-Balancing-Card-Palette-Board-for-Superior-Digital-Color-Correction-Photography/32838095942.html

Is it worth getting Color Checker Passport?

stoney — Tue, 05 Jul 2011 11:19:37 +0000

I use GH1 and GH2 for photo, too. The adjustment from Color Checker Passport looks great, but $99. Is it worth?

http://forums.dpreview.com/forums/readflat.asp?forum=1041&message=37905620

Lens resolution: your lenses are worse than 4k video

apefos — Thu, 12 Nov 2015 14:05:20 +0000

It seems that lens resolution will be an issue for the 8k video. In the lenstip website they do measurements about lens resolution in line pairs per milimeter (lp/mm) and also with resolution charts.

The average resolution for a full frame lens is around 45-50lp/mm and a great m43 lens is around 77-82lp/mm. The resolution charts shows the lenses at around 2000 - 2600 lines resolution maximum in still photos. Using a full frame lens in m43 sensor is worse because the sensor magnify the center area so the lp/mm will be half compared to same lens in a FF camera, a focal reducer can help a lot.

So the still lenses can work good up to 4k resolution, sometimes lower resolution than 4k video, and maybe for 8k video there will be the need of new special lenses, high price.

Considering that the indie people can buy only low price lenses, so work with 8k video will not make sense. 4k video is the maximum resolution for our photo/still lenses, no matter they are m43, aps-c or ff lenses.

Example: the 12-35 lens at f4 is around 77lp/mm in the image center, the GH4 sensor in 4k is 8.1mm height, doing the maths this lens will resolve around 1250 lines in GH4 4k video.

The new full frame Sigma Art 20mm 1.4 can do around 47lp/mm, so it will resolve around 770 lines in GH4 4k video. With a focal reducer this can increase to around 1080 lines. Most good Full Frame lenses are around a 50lp/mm maximum, and this is stoped down to f5.6

In a full frame camera, considering the sensor 36 x 20,25mm, this same sigma lens can resolve around 1900 lines.

The RGB bayer pattern decreases the camera resolution a little bit, around 1,33x less than the pixel count, so a 2160p video will deliver a maximum 1620 lines. The GH2 is 1080p and is around 810 lines.

Lens resolution is a good reason for Panasonic release new cameras with the multi aspect sensor, a bigger sensor can use more image area form the lens and record higher resolution, more lp/mm. The GH4 sensor is 8.1mm height, 1250 lines with the 12-35 lens. The multiaspect sensor with 3840x2160 pixels for video would be 10,09mm height, and could record 1560 lines from the same lens.

All these maths shows that 4k video is the sweet spot resolution for a video camera and for the lenses we can buy, and all these maths are in image center, in corners the lenses resolution is worst.

Table of the Hacks

blazer003 — Wed, 22 May 2013 17:32:29 +0000

I was heavily involved in testing and created my own personal custom settings for the GH1. I had the camera before it was ever hacked and was really happy to be able to boost its performance. At that time I had lots of extra time to keep up to date with all the patches and to an extent, knew what each patch did.

I was late to the GH2 game (as I really was fine with my GH1 other than the terrible green banding in low light that my camera produced. Honestly, it was one of the worst I've seen of any examples) and my job in the last couple years has been more projects and less time to dink around (I'm not complaining). So I've messed around with Flowmotion, and Sanity, not as much with Driftwood as I don't have 95 MB/s cards and don't have the time. But there are so many hacks, variations of Driftwood hacks especially, that I'd like to try out, but even being an "experienced" GH hacker, there are so many out there I have a hard time wrapping my head around what they do, or claim to do and what the new settings are.

Really, it's been this way for anyone coming into the GH hacking world from the beginning with the GH1. Tons of information spread across tons of forums and topics.

So, my question is: Is there anywhere that has a simple table with a lot of the major settings and some information on what their claims, bitrates and GOPs are? Something like the attachment below (this data is probably NOT AT ALL accurate, I'm doing it as an example). If there isn't one, doesn't anyone else think that this would be extremely helpful, especially for someone who isn't on the forums every couple of days keeping updated on the latest and greatest patch? I could have done this for the GH1, but I'm not qualified (as I stated above) to do this for the GH2.

Is there someone willing to put together a rough list? Maybe a wiki page somewhere so others can add details to each?