M240 focus calibration with CV 35mm 1.4II MC and TTArtisan 50mm 1.4

[kuchars22]

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Hi all,

I bought the CV 35 1.4 II MC as my first lens when I acquired the M240 a few weeks ago, my first ever Leica. Having used it for a week, I thought nothing of it in terms of sharpness, other than I thought it was a bit soft in the centre, and put it down to being a "classic" lens. Then I got the TTA 50mm 1.4 which came with a focussing chart - I calibrated this to the body and is now pin sharp. So I decided to use the same chart for the CV lens and discovered the softness was due to some front focussing. Would it be better to calibrate the RF to the CV lens (which doesn't offer self-calibration), and then calibrate the TTA lens to the "calibrated" body, or simply replace the CV and get the TTA 35mm 1.4 and self-calibrate that also? I'm not a fan of sending my kit away for weeks or months for £££, so I'd rather do things myself where possible. I've seen videos of people calibrating the horizontal cam with a hex bolt, and the vertical adjustment inside the top plate - is this effectively what needs to be done for an RF calibration?

Also, the TTA focus chart is tested at 2m from the focal plan and at 30degs. Does this method allow for the widest possible focus window from closest to infinity?

Thanks for your input.

[kuchars22]

Strangely, I just re-did the test and it appears to be working ok now?! I shot it on a tripod at all apertures using the RF focussing, then repeated again using Live View and both are the same in terms of sharpness! Whereas the in the first test I did prior to posting my thread, I focussed using LV, and looked through the VF to see that the patch wasn't aligned (which lead me to writing this post). Confused.com. However, I would still like to know the answer to the question about RF calibration. 

[a.noctilux]

😄

it's time to take real pictures now.

In my way of thinking, only real use can be considered "calibrated gear" or not.

[tom.w.bn]

The CV 35 Version II should not behave like that. Version I had focus shift issues they should be gone with version II. I would not consider the multi coated version a "classic lens" where some optical flaws are part of the charme.

Giving your camera and lens away to calibrate them correctly has the danger that the lens is not 100% ok and then your rangefinder is calibrated to a faulty lens. Imagine buying a 3rd lens that is perfectly ok... what then....

Don't overthink the calibration process. The TT Artisan needs a basic calibration. Without that I would not go out and use it for real photos. If you don't have problems in real world scenarios, I would not try to calibrate more or repeat it.

I have the TT 50mm. When thinking about a 35, I'd rather buy the CV 35 Version II and not the TT 35 because I wanted the 35 to be small.

[kuchars22]

Yep, same thinking in terms of setup. I’m no longer shooting professionally so the Leica is just for pure personal and emotional shooting.

Been out today and just editing my 35 shots - they’re nice and crisp. The city walk didn’t suit the 50mm so didn’t try that, but with Halloween street parties tomorrow I will give that a go then. 

One thing I want to add: the photos are much sharper when viewed on a “secondary display” in Lightroom, compared to an Original preview on the main screen - anyone know why?

Edited October 29, 2022 by kuchars22

[sometimesmaybe]

On 10/30/2022 at 6:39 AM, kuchars22 said:

One thing I want to add: the photos are much sharper when viewed on a “secondary display” in Lightroom, compared to an Original preview on the main screen - anyone know why?

short answer - it's old(er) tech

longer answer - low screen resolution and different LCD panel tech used: 

• the 3inch LCD screen has around 920k dots, which sounds impressive but that's only around 640 x 480 of resolution (or 0.3 megapixel); and
• the LCD is a TFT panel (which comes with it's own pros/cons). Your secondary screen prob uses an OLED or an IPS panel (which tend to have better colour accuracy and contrast).  

[kuchars22]

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8 minutes ago, sometimesmaybe said:

short answer - it's old(er) tech

longer answer - low screen resolution and different LCD panel tech used: 

• the 3inch LCD screen has around 920k dots, which sounds impressive but that's only around 640 x 480 of resolution (or 0.3 megapixel); and
• the LCD is a TFT panel (which comes with it's own pros/cons). Your secondary screen prob uses an OLED or an IPS panel (which tend to have better colour accuracy and contrast).  

I mean on my computer monitors, not the camera’s lcd monitor. I’ve got a triple monitor setup but use one screen for the main develop module, and the secondary display as a loupe. The loupe display is higher resolution than the develop screen, even though i’m supposed to be using full res 1:1 preview

[sometimesmaybe]

4 hours ago, kuchars22 said:

I mean on my computer monitors, not the camera’s lcd monitor. I’ve got a triple monitor setup but use one screen for the main develop module, and the secondary display as a loupe. The loupe display is higher resolution than the develop screen, even though i’m supposed to be using full res 1:1 preview

i see... 

I dont use lightroom so i cant comment on whether this is a software/hardware issue, but it might be worth checking the capacity of the dock or the cables being used to connect your monitors to your GPU. i think you need HDMI 1.4 or DP1.2 to support 4k