Image not sharp at infinity stop

[Chazphoto]

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Hi,

I've now experienced this with two 50mm APO-Summicron lenses and wanted some advice.  I've taken photos with the focusing ring turned to infinity, using a sign or similar in the middle of the frame at some distance away, to check for infinity focus.  In both cases, the writing on the sign was blurred.  Recently comparing with a 50mm Summilux-ASPH and the same procedure, the writing was clear.  I'll post the images when I get to the home computer, but would like some advice as to what I'm seeing, please.  I'm wondering if the sign I'm photographing is not actually far enough away to be infinity as far as the 50mm APO is concerned?

Note, this is not a case of photo sharp and viewfinder not-aligned at infinity stop, which is often discussed.

Thanks

 

Chazphoto

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[wizard]

vor 17 Minuten schrieb Chazphoto:

using a sign or similar in the middle of the frame at some distance away

To be sure, that sign should be at least 100m, better still at least 500m away. And you do need to make sure that the camera is held absolutely still during exposure, so better use a tripod or a shutter speed in excess of 1/1000s.

[charlesphoto99]

I have a 135mm APO that started to fall apart on me so I sent it off to DAG. Once back, I was amazed at how much more focus room there was near infinity. Before, lets say I was photographing an airplane (a series I'm working on) and I'd just ram it to infinity and it told me I was in focus (thankfully usually covered by DOF). Now I actually have lots of room and after what I thought of as infinity. In fact, the Cascade mountains from our living room, about 50 miles away, are not at infinity but just slightly below, this all with the rangefinder, not EV.

[Huss]

3 hours ago, Chazphoto said:

Hi,

I've now experienced this with two 50mm APO-Summicron lenses and wanted some advice.  I've taken photos with the focusing ring turned to infinity, using a sign or similar in the middle of the frame at some distance away, to check for infinity focus.  In both cases, the writing on the sign was blurred.  Recently comparing with a 50mm Summilux-ASPH and the same procedure, the writing was clear.  I'll post the images when I get to the home computer, but would like some advice as to what I'm seeing, please.  I'm wondering if the sign I'm photographing is not actually far enough away to be infinity as far as the 50mm APO is concerned?

Note, this is not a case of photo sharp and viewfinder not-aligned at infinity stop, which is often discussed.

Thanks

 

Chazphoto

It sounds like your lens is focusing past infinity, and needs to be adjusted.

[Chazphoto]

Hi guys and thanks.  I was just playing with the Summilux 50mm while waiting for fish 'n chips (!).  There is definitely more "room" between the hard stop and having a moderately distant object in focus.  As Wizard noted, I think that the first sign I photographed last weekend, was only a few 100 metres away and that may not have been far enough for hitting the infinity stop to be a good measure of focus.  The second photo was much further away.  Again, I will post the examples when I get home.

Tonight's "dry" experiments (nothing interesting to photograph near the fish 'n chip shop!) reminded me of how difficult it can be to tell what's in focus at such distances, hence the temptation to turn the focusing ring to infinity and leave it there.  It is almost more of a feeling of sharpness in the RF patch than seeing aligning edges.  Interesting that this was easier with the 135mm APO-Telyt once fettled by DAG.

Not sure that the 50mm APO lenses were focusing past infinity, but I didn't think to check.  I guess you could do that by shooting a succession of roadsigns on a diagonal stretching far away and focusing on the central one at 1000m+.  Would be tricky to find such a test site.

Cheers

 

Chazphoto 

[Chazphoto]

Here's the whole image, f2 50mm APO, focused on the "Rye Art" sign in the middle of the frame, by turning to infinity stop.   

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[Chazphoto]

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Same image with 50mm Summilux, focused the same way, also at f2.

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[Chazphoto]

Here are the second pair, where the centre of the image is a lot further away.  Both at f4.  First from the 50mm APO:

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[Chazphoto]

And here is the same scene with the 50mm Summilux at the infinity stop and at f4:

 

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[Chazphoto]

Centre of 50mm APO on second pair:

 

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[Chazphoto]

Centre of 50mm Summilux shot:

 

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[Jon Warwick]

Is the focus ring not getting to infinity, or is it focusing way beyond it?

My M 75 Summarit appears to do the former now, ie, when I rotate the focusing ring in the direction of infinity, I can see the split image heading close to, but not fully getting to where it should be, ie, there is simply not enough turn in the focusing ring beyond its hard stop now to get infinity in focus.

My lens feels like the focusing ring has uneven resistance, as though it “slips” when it goes through a part of its rotation and the focus ring grates a bit. I don’t know quite what’s wrong with it and causing all this, but pretty clear that my lens likely needs some love and attention in Wetzlar!!

Does your 50 APO feel like it has any mechanical issues when you use it?

Edited September 1, 2023 by Jon Warwick

[Chazphoto]

Hi Jon

 

thanks for asking.   I was borrowing the 50mm APO so it was new to me.  However, it felt mechanically fine with a smooth-running focus ring all the way round , without stiffness and no difference in the torque required to turn it.  Focused fine at all other distances, if I did my job correctly. 

I hope you find a solution for your Summarit   

Chazphoto

[Chazphoto]

No one with a similar experience?  I don't have the borrowed lens, so can't continue to check, but I wonder if I needed a shade less than full turn to infinity stop on even the photograph of the fairground?  

The 50mm APO-Summicron-M receives some negative comments from time to time and I'm really not trying to add to that (either with these observations or my other thread about needing a little slower shutter speed when at f2, compared to the Summilux-ASPH).  I'm still really drawn to the lens and the occasions on which I've borrowed one are making for interesting findings.  For one thing, I have confirmed for myself that the colour fidelity is a bit better than the 50mm Summilux-ASPH, which has a slightly yellow or warmer tone, visible in some lighting & subject conditions.  I'm also convinced about the full frame resolution compared to the 50mm Summilux-ASPH, though again where you need it and where you see it remain more relevant considerations than the fact that the lens can do that.  I've also been reminded, with both lenses, that my ability to get focus right is a much larger variable than the two lenses!

But, focusing using the infinity stop on the ring should eliminate that, right?  If the subjects are at infinity and the lens is working as it should.

Thanks

Chazphoto

[Photoworks]

The lenses are fine mechanics. especially with the new versions with FLE, They benefit from adjustments.

I have sent a few lenses for calibration to the local Leica service and they all came back in perfect focus. It is a routine adjustment and in many places, it can be done on the same day.

 

[hmzimelka]

On 9/1/2023 at 5:19 PM, Chazphoto said:

Hi,

I've now experienced this with two 50mm APO-Summicron lenses and wanted some advice.  I've taken photos with the focusing ring turned to infinity, using a sign or similar in the middle of the frame at some distance away, to check for infinity focus.  In both cases, the writing on the sign was blurred.  Recently comparing with a 50mm Summilux-ASPH and the same procedure, the writing was clear.  I'll post the images when I get to the home computer, but would like some advice as to what I'm seeing, please.  I'm wondering if the sign I'm photographing is not actually far enough away to be infinity as far as the 50mm APO is concerned?

Note, this is not a case of photo sharp and viewfinder not-aligned at infinity stop, which is often discussed.

Thanks

 

Chazphoto

The APO Summicron-M 50mm I briefly owned for all of one day also didn't reach infinity focus... probably around the 50 meter mark, which left infinity slightly defocused up until f/4. Focus was at least accurate, but the rangefinder patch didn't line up with infinity subjects. I wasn't too surprised, as my experiences with Leica products hasn't been great. A lot of problems! 

[lct]

I would check in LV mode with focus magnification. If the focus point is still blurred, at the same shutter speed and aperture, the lens needs calibration.

[Chazphoto]

Thanks all.  @hmzimelka, I remember reading your blog entry about the lens; seems that you had a rotten copy. 

@lct Wish I had thought about that!  Certainly would help to know whether I had hit focus correctly or needed to dial back that fraction, because what I was focusing on wasn't far enough away.  Not something I can tell in the rangefinder patch.  As I explore further, I will remember that advice, thanks.

Regarding CLAs, repairs, fine-tuning etc. we have no DAG equivalent in the UK.  Although I heard good things about the Leica Store Manchester repair service, they don't service the digital cameras or the lenses, as far as I can see.  Leica Mayfair are very helpful and organised sending my 90mm Elmarit-M to Wetzlar during the pandemic for 6-bit coding (a good use of pandemic time-out, I thought), but if I find a 50mm APO-Summicron that I can actually afford to buy, I'd rather I didn't lose it for 2 months at the outset.  

Cheers

 

Chazphoto

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[hansvons]

15 hours ago, lct said:

I would check in LV mode with focus magnification. If the focus point is still blurred, at the same shutter speed and aperture, the lens needs calibration.

 

This. Leica lenses have a hard infinity stop. When you reach that, the lens “sees” infinity. A 50mm at f4 and a distance of 400+ metres should render tack-sharp images in the centre. It not, your lens either refuses to reach infinity or goes beyond infinity. We are talking half millimetres here. Both can happen, the latter is a regular when adapters are involved. 

From what I can make of your pictures I’d send it off to a CLA. Any reputable camera repair shop with Leica experience can do that. I’m sure there are a few in the UK. Just ask the forum. 

Edited September 7, 2023 by hansvons