p.1 #1 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Thought I would start this thread as Fred and I both have this lens and we both bought PCX Front Filters for it. Those filters come in the end of the week so we will be updating this as we start our testing. Now I want to be careful here as the Filters we bought are Guy PCX 2000 and Fred PCX 2500. What I am going to show here is the WRONG front filter but one that is on hand that we use for the CV 35 1.7 lens which has less field curvature and we use a PCX 5000 which is weaker to control the field curvature of the 35mm. By simulation the CV 28 needs either a PCX 2000 or 2500 to fully correct the field curvature. Im not going to post too much using the PCX 5000 because again it is NOT THE CORRECT FILTER for the CV 28. But it does show improvement in the native lens, its just not enough even though with PCX 5000 F8 looks to be very good. The goal here is getting it to about F4 with the stronger PCX 2000/2500.
Again I repeat this is the WRONG filter but gives us a good idea what to expect as we get our stronger PCX 2000/2500 filters.
Also to be clear this is the lens we are talking about:
p.1 #2 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
The shots are At F2 wide open for this lens and as you can see the 28 Ultron has a lot of filed curvature. Pretty obvious in the picture of the lens itself. Here are two images both at F2 with no filter and the wrong filter the PCX 5000.
I will just do F2 and F5.6 crops as I really just want to show WHATS POSSIBLE with the correct filters of the PCX2000/2500.
p.1 #3 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
As you can see even at F2 there is a big improvement in the corners. So we are on the right path here and going forward with the correct filters F2 should really look good and if we can hit the goal of across the frame sharpness at F4 or F5.6 than this will be a outstanding small, light weight lens to have in the bag. Also the 28 has a focus tab which is really nice for focusing. Okay lets do a couple crops
p.1 #4 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
I should note on center this lens is very close to the 35mm 1.7 and I did do a center test that I will show that comparison. The 35mm 1.7 is a notch better at F2 but its very close.
p.1 #7 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
On center it looks to be very even which is expected as we really are not correcting center but mid frame and corners/edges. But even with the weaker filter there is much improvement.
Im going to do F5.6 as thats really the end goal or F4 to get even across the frame.
p.1 #8 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
As you might expect we are being the Guinea Pigs here and Actually Fred was the first Guinea Pig here and I followed him. My 28mm happens to be a good copy but Freds went back for exchange. He should have a fresh one today along with the CV 40mm 1.2 to test, so he is going to be busy this week. I hope he will join me here with his outstanding infinity test on the Ultron 28mm. I love his infinity tests as they are a perfect spot to shoot them, I know I was there at his house.
p.1 #9 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
GMPhotography wrote:
As you might expect we are being the Guinea Pigs here and Actually Fred was the first Guinea Pig here and I followed him. My 28mm happens to be a good copy but Freds went back for exchange. He should have a fresh one today along with the CV 40mm 1.2 to test, so he is going to be busy this week. I hope he will join me here with his outstanding infinity test on the Ultron 28mm. I love his infinity tests as they are a perfect spot to shoot them, I know I was there at his house....Show more →
Good idea to start this thread Guy.
Last week, I posted a 1:1 crop showing the extreme corner with a CV 28/2 Ultron + PCX5000...which is the wrongfront-lens for this lens.
Still, the extreme corners looked great starting at f/6.7. I'm hoping that the PCX2000 or 2500 will make this even better and according to simulations, it will. The CV 28/2 is an awesome little lens...very well-built wit tight tolerance. Mechanically, it reminds me of a Leica lens and it even has a focusing tab (metal whereas the Leica is plastic).
I like it even better than the 35/1.7 Ultron in terms of build.
p.1 #10 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Thanks Fred
I should point out right now and this is important folks. We are using the same L to M adapter from K&F concepts and the reason for this when we add the PCX in any strength we need to extend our infinity, a normal adapter like a Hawks of VC or even just a standard adapter we can't extend to infinity. For some unknown reason the K&F will but it has some variance here as well. I have 3 and only 2 work. Here is a link to what you need. As far as the front filter setup it will be the same as the 35 1.7 which Fred has a link to to add to this thread so your all on the same page.
Here is the link to the adapter that we both are using. I think you can buy them off eBay as well
p.1 #11 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Lets move on to 5.6 just to show how much the improvement is getting on this great little lens. BTW new this only cost 600 dollars and with PCX , adapters and setup. 750 total so very affordable for a great little 28mm
p.1 #14 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
As you can see some real improvement especially in the corners. Now I think the mid frame is still weak but with the stronger PCX of the 2000/2500 is where things will improve. On center again its very sharp with or with. Bottom line its getting better across the whole images even with the weak filter.
Now i want to stop here because its the wrong filter and next we will consentrate on the filters that the simulation called for the PCX2000/2500
But up to this point I just wanted to show what is possible. This thread will get updated as we continue on in our testing.
But one other thing I wanted to show was on center of the little Big Bronco scene and here I used the ubber sharp VC 35mm 1.7 lens at F2 and the 28 at F2. Obviously the 35mm gets a slight 1/3 a stop edge and thats great but the 28mm looks really good against it.
2) The second shows the same simulation including the PCX 5m which is the PCX Guy and I used for the samples above. (As you can see it's not optimal)
3) I just got this simulation and it shows the PCX 2m and 2.5m at smaller apertures, particularly f/5.6 and f/8.
They look very similar with the 2.5m slightly ahead at f/5.6 and f/8
So, it looks like the PCX 2m is better wide open (f/2)
At f/4 both PCX 2m and 2.5m are very similar and starting at f/5.6, the 2.5m is slightly head.
Keep in mind these are simulations based on a perfect lens. Actual results will of course vary.
p.1 #16 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
I bought this 28/2 lens two months ago, and I don't see this kind of smearing without any filters when attached to my M-mount cameras which are all film based. So far I really like this lens. A few examples below:
p.1 #17 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
And thats a great point as these VC M mount lenses are designed for Leicas sensor stack and film bodies which is thinner than Sony's and that is where our problems lie. Glad you posted that as it explains how good this lenses are for Leica bodies but not on Sonys and we have to make these adjustments.
p.1 #18 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
GMPhotography wrote:
And thats a great point as these VC M mount lenses are designed for Leicas sensor stack and film bodies which is thinner than Sony's and that is where our problems lie. Glad you posted that as it explains how good this lenses are for Leica bodies but not on Sonys and we have to make these adjustments.
This was not my conclusion. I don't see any debit with this lens when also mounted on my A7R - if there is a slight corner smearing, it is unrecognizable in the real world photos taken with this combo without pixel peeping. My point was that I don't find any need for this kind of filters not even when combined with the Sony camera. It was one reason why I decided to buy this lens because by not being an ASPH lens, it shows much less - negligible IMO - corner issues with the Sony sensor than other rangefinder-based 28 mm lenses do.
p.1 #19 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
retrofocus wrote:
I bought this 28/2 lens two months ago, and I don't see this kind of smearing without any filters when attached to my M-mount cameras which are all film based. So far I really like this lens. A few examples below:
Yes, the goal here is to make the CV 28/2 Ultron + PCX lens work just as good on the Sony body as it does on the Leica. (which is the camera it was designed for)
p.1 #20 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Fred Miranda wrote:
Yes, the goal here is to make the CV 28/2 Ultron + PCX lens work just as good on the Sony body as it does on the Leica. (which is the camera it was designed for)
As I said in my response to Guy above, I don't think this kind of filters are needed at all with this lens when mounted on a Sony camera - at least telling from performance on my A7R. The last two photos in my post above were taken with the Sony A7R and this lens (with Fotasy M/E-mount adapter).
