tbpeur01 wrote:
I’m a big fan of this lens so far - the combination of sharpness, size, and rendering, along with the extra bit of reach, means this one will see lots of use. The first image is to simply show the bokeh and sharpness wide open. The last few were added for good measure.
The rendering looks nice here, but it would look even better on the wide open shots if you were in full mechanical shutter - there's noticeable bokeh clipping due to electronic first curtain in the wide open shots that reduces the quality of the bokeh a bit. But nice shots nonetheless!
chiron wrote:
Great work on the comparisons. You've created a classic thread. Now to update with the 35 GM and then to do the 50/55mm lenses when the GM is here. Then the 40/45 lenses.
Then the 85's!
Too much work and those are no my preferred FL's!!!!!! But, I do hope do a comparison with the GFX 45, GM 35, 35i with one or two others at some point. Lately I have been into diffusion filters of different types, which are vastly underrated IMO. I think I might do some more posting on those, though people probably don't care that much.
Just received the 65mm this afternoon and went for a walk to local garden and captured this image. Not a pretty image and shot at f11, but I do like the rendering.
I want to save readers, especially nehemiahphoto, a wade in the swamp that surrounds the terms 'Field of View' and 'Angle of View'. Some love this kind of thing as much as I do not. A fair reasoning is this:
'whilst AOV and FOV are different things, they are both measured as angles...it states that AOV is a property of the lens and does not change no matter what size of sensor is in the camera, whilst FOV is a function of the lens AND the sensor size.' Much more on the subject here if you are in the 'need to know' camp:
Now all that matters is what makers report and what actually happens. The reason for the second part of the sentence is (i) the alarming rise in the tendency for distortion correction, and its implications for stated AOV/FL, together with (ii) the often outrageous levels of breathing in stills lenses.
Makers report AOV in the places I look for the data, usually B&H, or Cosina or Sony, probably others too. So you get numbers like 62.0, 63 or 63.4, and whole integers will most likely be rounded and will not be perfectly accurate, but are still better than nothing. Back when makers treated users with less contempt, Carl Zeiss used to report minutes as well as degrees (there are 60 minutes to a degree for the angle calculation).
Once you have these AOV data, you can search all the technical waffle (the data swamp) for a simple text entry field that converts AOV to focal length. I use this one below not because it is 'better' but the other sites bury this very useful feature amongs the impenetrable related information they want to assail you with:
Of course it is called 'FOV', but we all use the same sensor dimensions give or take, so I believe you can press on here. Enter your AOV in the right side text entry field and read off the equivalent FL to the left.
To complete the exercise here are the derived FLs of the lenses you cite, gained from the Pentax site:
CV M 35/2 APO - 34.9mm
CV E 35/2 APO - 35.9mm (different!)
CV 35/1.7 - 36.0mm
CV M 35/1.2iii - 36.3mm
CY 35/1.4 - 35.7mm
RX1 - 35.3 (post correction, we can be certain of this!)
Sigma 35i - 35.0mm
AOV data are almost aways listed in 'Full Specifications' or similar page titles. Others will likely have better formulas/calculators - the topic should be an Alt lens FAQ, I think. Or somewhere easier to find than here. Of course if we had breathing data, we could see close and infinity FLs, then we could get ready for a real surprise:
'The AOV of a lens is based on the lens *focused to infinity* using the sensor (or film) size for which it was designed.' Breathing varies greatly among lenses, leading to incorrect assumptions on 'taken image AOVs/FLs' shorter than infinity. Imagine knowing the true FL of a portrait lens at acceptable portrait distances, say 2m? From the DPR lens reviews (they do this well now as they know video is getting bigger) it seems breathing is fairly linear as one pulls focus.
Do you know of a way to calculate/tell actual FL beyond shooting crops/comparing lenses?
The stated FL's aren't that accurate often--the three (35/2, 35/1.7, 35/1.2iii) CV's and CY 35/1.4 are much tighter than the RX1 and 35i.
No easy calculator for that. Usually manufactures provide 'precise' angle of view numbers for their lenses (measured at infinity) and whenever lenses with equal FL have different AOV numbers, it's a good hint.
For example, Sigma says the 35/2 DG DN AOV is ~0.5 degree wider than the new GM. Not sure if this is before or after correction so this number may not consistent between brands.
Since I usually test lenses at infinity using the same subject and framing, it's noticeable when a lens is wider or narrower than another but the 'real' FL is only an approximation. I would also add that I never correct for distortion (in-camera or in post)
If I understand this correctly... *Toggle the lens FL/MM and compare Angle of View or sometimes presented as Horizontal, Vertical and Diagonal AOV or Field angle or just one AOV number provided on the lens data sheet, this will give an approximation on the true FOV based upon Angle of View specs
I am thinking about replacing my 35 ZA and 35 Bigma with 35I. I have a fast toddler and both my 35s can keep up with her. I feel 35 ZA is slightly faster, but both lenses are pretty fast. Is 35I slower than Bigma? If yes, that will be a deal breaker for me. GM is nice, but still big and I really don't want any of my lenses to be over a lb.
35I is ticking most boxes for me, but Sigma 45C has my confidence shaken in Sigma's AF capabilities. 45C and CV 50/1.2 are my most frustrating lenses for toddler photography and two of my best lenses IQ wise.
ramesesthe2nd wrote:
I am thinking about replacing my 35 ZA and 35 Bigma with 35I. I have a fast toddler and both my 35s can keep up with her. I feel 35 ZA is slightly faster, but both lenses are pretty fast. Is 35I slower than Bigma? If yes, that will be a deal breaker for me. GM is nice, but still big and I really don't want any of my lenses to be over a lb.
35I is ticking most boxes for me, but Sigma 45C has my confidence shaken in Sigma's AF capabilities. 45C and CV 50/1.2 are my most frustrating lenses for toddler photography and two of my best lenses IQ wise....Show more →
I sold my 35i for the reasons you mention needing it above - couldnt quite keep up with my kids. Granted I shoot on the older a7rii, but it wasn’t as reliable as the ZA or 35/1.8.
GMPhotography wrote:
A7rII is not AF fast at all. I had a lot of issues with it on the speed side
Yeah, I seem to be in the minority on this topic, but one of the earlier posters on the 35 gm thread had both the 35i and 35 gm on the a7r iv, and he felt the gm was considerably better in af among other areas (member lifeandmylens).
Fred Miranda wrote:
No easy calculator for that. Usually manufactures provide 'precise' angle of view numbers for their lenses (measured at infinity) and whenever lenses with equal FL have different AOV numbers, it's a good hint.
For example, Sigma says the 35/2 DG DN AOV is ~0.5 degree wider than the new GM. Not sure if this is before or after correction so this number may not consistent between brands.
Since I usually test lenses at infinity using the same subject and framing, it's noticeable when a lens is wider or narrower than another but the 'real' FL is only an approximation. I would also add that I never correct for distortion (in-camera or in post)...Show more →
Thanks. I only know from comparing lenses on tripod but often as real shooting distance, but that's a laborious way figure it out, and doesn't' account for focus breathing and such.
philip_pj wrote:
I want to save readers, especially nehemiahphoto, a wade in the swamp that surrounds the terms 'Field of View' and 'Angle of View'. Some love this kind of thing as much as I do not. A fair reasoning is this:
'whilst AOV and FOV are different things, they are both measured as angles...it states that AOV is a property of the lens and does not change no matter what size of sensor is in the camera, whilst FOV is a function of the lens AND the sensor size.' Much more on the subject here if you are in the 'need to know' camp:
Now all that matters is what makers report and what actually happens. The reason for the second part of the sentence is (i) the alarming rise in the tendency for distortion correction, and its implications for stated AOV/FL, together with (ii) the often outrageous levels of breathing in stills lenses.
Makers report AOV in the places I look for the data, usually B&H, or Cosina or Sony, probably others too. So you get numbers like 62.0, 63 or 63.4, and whole integers will most likely be rounded and will not be perfectly accurate, but are still better than nothing. Back when makers treated users with less contempt, Carl Zeiss used to report minutes as well as degrees (there are 60 minutes to a degree for the angle calculation).
Once you have these AOV data, you can search all the technical waffle (the data swamp) for a simple text entry field that converts AOV to focal length. I use this one below not because it is 'better' but the other sites bury this very useful feature amongs the impenetrable related information they want to assail you with:
Of course it is called 'FOV', but we all use the same sensor dimensions give or take, so I believe you can press on here. Enter your AOV in the right side text entry field and read off the equivalent FL to the left.
To complete the exercise here are the derived FLs of the lenses you cite, gained from the Pentax site:
CV M 35/2 APO - 34.9mm
CV E 35/2 APO - 35.9mm (different!)
CV 35/1.7 - 36.0mm
CV M 35/1.2iii - 36.3mm
CY 35/1.4 - 35.7mm
RX1 - 35.3 (post correction, we can be certain of this!)
Sigma 35i - 35.0mm
AOV data are almost aways listed in 'Full Specifications' or similar page titles. Others will likely have better formulas/calculators - the topic should be an Alt lens FAQ, I think. Or somewhere easier to find than here. Of course if we had breathing data, we could see close and infinity FLs, then we could get ready for a real surprise:
'The AOV of a lens is based on the lens *focused to infinity* using the sensor (or film) size for which it was designed.' Breathing varies greatly among lenses, leading to incorrect assumptions on 'taken image AOVs/FLs' shorter than infinity. Imagine knowing the true FL of a portrait lens at acceptable portrait distances, say 2m? From the DPR lens reviews (they do this well now as they know video is getting bigger) it seems breathing is fairly linear as one pulls focus....Show more →
Very interesting. Thanks for taking the time to compile this response with links. The values you've stated line up with my experience. One point of interest here. According to the Zeiss data sheet for the CY 35/1.4, the actual FL is 36.5, while the nominal is obviously 35mm, with a FOV of 62 degrees.
However, on the linked Pentax calculator above, the FL is 36.003 mm when plugging in Zeiss measured horizontal FOV of 62 AOV value. Not the 36.5mm stated on the Zeiss data sheet. Maybe it's a breathing differential?
Grahamc wrote:
I thought this was the 65mm thread??
The last 10 posts were about the 35mm or not 35mm??
Just asking.
Photographers break the rules. Actually it is quite common to see how a lens renders along with its brother or sister in the same class . Given the 65 for me I wanted to match it with a 35 than would be both small and render similarly. I’ll get the GM even though I may not keep it but now I’ll have a 2 lens combo that will match each other. Secondly you don’t learn shit unless we talk about these things. I’ve been around forever and I always still learn something , so if you don’t want to learn and be a better shooter than don’t come along at all and stick to the same beer daily. At least we did not jump to canon or Nikon which makes me want to puke every time they are brought up.
tbpeur01 wrote:
Yeah, I seem to be in the minority on this topic, but one of the earlier posters on the 35 gm thread had both the 35i and 35 gm on the a7r iv, and he felt the gm was considerably better in af among other areas (member lifeandmylens).
I wonder if that is because the 35i seems to only use contrast detect in AF-S, I'm not sure if that is common with third party lenses (and maybe even Sony's own) but I was shocked at how much faster the 35i is in AF-C. It's like a different lens, I am using an A7R III.
