First 7Artisans 35mm f/2 Lens Review

[Guest]

Advertisement (gone after registration)

On ‎6‎/‎22‎/‎2018 at 2:05 AM, Ecar said:

Yes, adjusting for infinity should give you accurate focus across the range, although there will always be a hint of focus shift (it's a Sonnar-based optical formula after all).

While the 50/1.1 was essentially spot on upon arrival, the 35/2 was way off. The good news is that it took me less than 15 min to adjust with the screwdriver provided.

Focus is very smooth and almost Leica-like on my copy, with no rough spots, but the aperture ring is slightly wobbly and clunky. Time will tell if it ends up falling apart...

I have only managed to take a few shots with it so far, so no opinion on IQ yet.

How did you calibrate your lens?

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[TomB_tx]

The procedure and a focus chart should have come with the lens. You have to compare the recorded image with the RF focus point to see which direction it is off, then loosen two screws anchoring the focus cam and shifting it as indicated and tighten it again. Much easier with digital and live view. Perhaps you can borrow an M10 to adjust it.

They say to adjust at 2 meters, which is a good compromise. However I notice on mine the slope of the focus cam is slightly off, for when it is right on at 2 meters it has slight front focus at 1 meter, and back focus at 3-4 meters.

[david strachan]

1 hour ago, iancaldo said:

How do you calibrate the focus of the lens? I'm using film, so I can't really see the results (picture) right away. I did get my first roll and some are slightly out of focus.

Ian

Can you do focus tests on grease-proof paper stuck on the film rails with back open.  The paper acts as a screen so you can see any adjustments...might need a loupe.

...

 

 

[Ecar]

1 hour ago, iancaldo said:

How did you calibrate your lens?

I used a digital M with LV. I appreciate it's not as simple with film. Is there any dealer near you that would let you borrow an M240 or M10?

[Guest]

34 minutes ago, david strachan said:

Ian

Can you do focus tests on grease-proof paper stuck on the film rails with back open.  The paper acts as a screen so you can see any adjustments...might need a loupe.

...

 

 

Is this similar to what you are suggesting?

 

[Guest]

Assuming that my Leica M2 is perfectly calibrated (it was recently CLA'd by Kanto Camera), here's what I did..

I selected a distant vertical target (about 3 kilometers away) and push the focus tab all the way to the "infinity stop". At this point, the rangefinder patch shows that the target is not in focus (not aligned). I adjust the lens (turning clockwise about 0.5mm-1mm) so that the target is perfectly aligned to the rangefinder patch.

Would this be enough?

[david strachan]

Advertisement (gone after registration)

3 hours ago, iancaldo said:

Is this similar to what you are suggesting?

 

Yes.

...

[david strachan]

Hi ian

You should check any adjustments in real time using the ground glass screen method...waxed paper, in this case.

I am not aware of Artisans calibration methods, perhaps someone else can help.  Definitely better if you can borrow a digital M series which is known to be calibrated.

Good luck.

[Guest]

2 hours ago, david strachan said:

Hi ian

You should check any adjustments in real time using the ground glass screen method...waxed paper, in this case.

I am not aware of Artisans calibration methods, perhaps someone else can help.  Definitely better if you can borrow a digital M series which is known to be calibrated.

Good luck.

I tried the ground glass method. I used a semi-transparent scotch tape as mentioned in other forums. I was able to check the focus real time. When the target is in focus, the distance of the camera to the subject does not match the lens distance scale, and the RF patch is way off. However, when I adjust the RF patch to perfectly align it to my subject, the distance scale is correct. But the image in the ground glass (scotch tape) is a little out of focus. I used a loupe just to make sure. I wonder if the distance of the tape from the lens is an issue? I try to tape it similar to where the film should be. 

 

[Guest]

A better approach would be to go to the Leica store and borrow their M10. 

[Guest]

or test a roll of film with focus in different distances? 

[TomB_tx]

If you have an M10 (or other digital M with live view) the adjustment is fast and easy, and doesn't really need a graduated focus chart. You just need an object with clear detail around a point on which to focus. Mount the camera on a tripod, ideally about 2 meters from the target, and focus the rangefinder exactly on the target. (In this example I used a closer distance so the indicator marks I made would be easier to see.) Then use a sharp (0.5mm) pencil to mark on the lens distance scale where the RF shows it is in focus:

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Then, without moving the camera or target, switch to Live View and use magnified focus to get the sharpest focus on the same target point. This will likely be a bit different than the RF if the lens hasn't been adjusted yet. Mark this point on the lens also:

The distance between the two marks is the amount the focus cam needs to move so that the RF indicated focus matches the true image focus. In this case, the lens cam needs to move clockwise so the RF will focus at the same point as the image.

To adjust, the lens helical must stay fixed while you move the focus cam, so it is easiest to do with the lens against the infinity stop. Remove the lens, set it to the stop, and mark the cam where it aligns with the edge of the bayonet tab. Then make another mark the same distance apart as the marks made on the distance scale, and in the same direction - so here the second mark is left of the mark at the stop:

Now slightly loosen the two screws that lock the focus cam in place:

Then, holding the helical against the infinity stop, rotate the focus cam until the "RF" mark aligns with the edge of the bayonet tab:

Snug up the two screws with the cam in this position and verify that it is aligned when the focus is at the infinity stop.

Then re-check the difference between the RF and Live View focus, and repeat if necessary.

This should adjust for all distances IF the focus cam on the lens is accurately ground. On my sample the cam slope is slightly off, so the focus drifts a bit as you focus at different distances. That's why Leica no longer uses a steeply sloped focus cam on their lenses.

 

Edited June 27, 2019 by TomB_tx

[TomB_tx]

BTW, I ran the same focus shift tests on this 7_A lens as I did on the new Voigtlander 35 f1.4 II, and the 7_A does not show focus shift that I can detect. Of course, shift is more likely on faster lenses. 

[Guest]

58 minutes ago, TomB_tx said:

If you have an M10 (or other digital M with live view) the adjustment is fast and easy, and doesn't really need a graduated focus chart. You just need an object with clear detail around a point on which to focus. Mount the camera on a tripod, ideally about 2 meters from the target, and focus the rangefinder exactly on the target. (In this example I used a closer distance so the indicator marks I made would be easier to see.) Then use a sharp (0.5mm) pencil to mark on the lens distance scale where the RF shows it is in focus:

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Then, without moving the camera or target, switch to Live View and use magnified focus to get the sharpest focus on the same target point. This will likely be a bit different than the RF if the lens hasn't been adjusted yet. Mark this point on the lens also:

The distance between the two marks is the amount the focus cam needs to move so that the RF indicated focus matches the true image focus. In this case, the lens cam needs to move clockwise so the RF will focus at the same point as the image.

To adjust, the lens helical must stay fixed while you move the focus cam, so it is easiest to do with the lens against the infinity stop. Remove the lens, set it to the stop, and mark the cam where it aligns with the edge of the bayonet tab. Then make another mark the same distance apart as the marks made on the distance scale, and in the same direction - so here the second mark is left of the mark at the stop:

Now slightly loosen the two screws that lock the focus cam in place:

Then, holding the helical against the infinity stop, rotate the focus cam until the "RF" mark aligns with the edge of the bayonet tab:

Snug up the two screws with the cam in this position and verify that it is aligned when the focus is at the infinity stop.

Then re-check the difference between the RF and Live View focus, and repeat if necessary.

This should adjust for all distances IF the focus cam on the lens is accurately ground. On my sample the cam slope is slightly off, so the focus drifts a bit as you focus at different distances. That's why Leica no longer uses a steeply sloped focus cam on their lenses.

 

THANK YOU VERY MUCH! 

I really appreciate this detailed instruction. I followed it, and adjust the lens accordingly. The lens now focuses correctly at infinity, and about 2 meters from the lens. Will need to test this on an M10, or a roll of film.

[AndreasG]

Tom,

in one of the photos in #132 I see the 6bit coding WBBBBW, same as the Summicron 2/35. I recently could test the 7artisans 2/35, S/N 6336xx, without coding, which showed substantial barrel distortion - not suited at all for straight lines outside the center.  Does the coding prevent or at least improve such distortion?

[TomB_tx]

1 hour ago, AndreasG said:

Tom,

in one of the photos in #132 I see the 6bit coding WBBBBW, same as the Summicron 2/35. I recently could test the 7artisans 2/35, S/N 6336xx, without coding, which showed substantial barrel distortion - not suited at all for straight lines outside the center.  Does the coding prevent or at least improve such distortion?

No - Leica 6-bit coding only corrects color casts and vignetting, not distortion. I ran a quick check today and the 7-A has similar barrel distortion to the Voigt 35 f1.4 Nokton, although the Nokton may be a bit more pronounced.

My 7-A came coded this way, but I hear they have stopped doing that.

Edited June 27, 2019 by TomB_tx

[AndreasG]

Thank you for the clarification, my impression of the non coded 7-A is that vignetting is not a big issue, however, I noted in the corner color casts in areas of high contrast. Not sure I should buy this lense...

[deathontheshore]

Am 27.6.2019 um 14:17 schrieb TomB_tx:

If you have an M10 (or other digital M with live view) the adjustment is fast and easy, and doesn't really need a graduated focus chart. You just need an object with clear detail around a point on which to focus. Mount the camera on a tripod, ideally about 2 meters from the target, and focus the rangefinder exactly on the target. (In this example I used a closer distance so the indicator marks I made would be easier to see.) Then use a sharp (0.5mm) pencil to mark on the lens distance scale where the RF shows it is in focus:

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Then, without moving the camera or target, switch to Live View and use magnified focus to get the sharpest focus on the same target point. This will likely be a bit different than the RF if the lens hasn't been adjusted yet. Mark this point on the lens also:

The distance between the two marks is the amount the focus cam needs to move so that the RF indicated focus matches the true image focus. In this case, the lens cam needs to move clockwise so the RF will focus at the same point as the image.

To adjust, the lens helical must stay fixed while you move the focus cam, so it is easiest to do with the lens against the infinity stop. Remove the lens, set it to the stop, and mark the cam where it aligns with the edge of the bayonet tab. Then make another mark the same distance apart as the marks made on the distance scale, and in the same direction - so here the second mark is left of the mark at the stop:

Now slightly loosen the two screws that lock the focus cam in place:

Then, holding the helical against the infinity stop, rotate the focus cam until the "RF" mark aligns with the edge of the bayonet tab:

Snug up the two screws with the cam in this position and verify that it is aligned when the focus is at the infinity stop.

Then re-check the difference between the RF and Live View focus, and repeat if necessary.

This should adjust for all distances IF the focus cam on the lens is accurately ground. On my sample the cam slope is slightly off, so the focus drifts a bit as you focus at different distances. That's why Leica no longer uses a steeply sloped focus cam on their lenses.

 

Hi,

this is my first post here. I am struggling with focus adjustment. I thought, I could adapt the lens on a mirrorless camera (Fujifilm X-T2) and use 7artisans adjustment tips. But when I rotate the focus cam nothing seems to happen, focus is still shifted. I rotated the focus cam clockwise until it can't be rotated any more. Does this only work with a digital M?

Thank you

[Advertisement]

Hallo,

Look here: Leica M

[TomB_tx]

Yes, the focus cam only has a function on the Leica M rangefinder. The versions for mirrorless don't have or need the focus cam.

[deathontheshore]

vor 17 Minuten schrieb TomB_tx:

Yes, the focus cam only has a function on the Leica M rangefinder. The versions for mirrorless don't have or need the focus cam.

I'm sorry, I didn't specify what lens I have. It is an M mount lens. Is it possible to adjust focus of an M mount lens adapted to a mirrorless camera?