Diffraction effects on medium format cameras 

When I was younger I just didn't care about technicality, I just shot and enjoyed myself. As I've gotten older, and picked up film once again, I find myself obsessing over optic perfection nonsense. It's almost disheartening. Digital ruined me in this regard - I want everything to be perfect. I've been trying to train that out of me, and it's been very helpful as I've picked up wet printing. Who knows how much paper I'd go through trying to be perfect. "Good enough" is truly the right philosophy.

reminds me of something my photographer friend told me when I started pointing out grain in a photograph I'd taken. He said "I believe anyone who insists on studying the grain of an image instead of appreciating its content is missing the point of a photograph" In short, if your image is strong, no one will care if it's got a little grain or not pin sharp. The photograph is what matters

Just dropping in to say thanks for your channel, Steve. You’re by far my favourite photographer on RU-vid, and I always leave with a thumbs up usually thinking, “What a lad!” - I really admire your approach and motivation, not least your style. So, thanks again for sharing your knowledge in the way you do. It’s much appreciated 🙂

That first photograph with the yellow filter, stopped down aperture and square format is absolutely excellent ! Thank you

Well said Steve. You don’t usually hear this much sense on RU-vid.

Also, great idea to use a tripod as often as practical and possible, even at much faster speeds ( my opinion ). Thank you again. Wonderful video.

"Sharp enough for me..." Spot on! And of course much depends on the print size. When I was shooting film forty years ago diffraction was something to be aware of, but not necessarily something to worry about. Out of focus is nearly always more detrimental. I think a lot of the current concern about it comes from the writings of digital photographers interested in the capacity to print very large. My life became easier when I decided to permit myself f16. I haven't noticed any problems at the modest print sizes I can afford, and as a result I'm willing to experiment further...

I think front to back sharpness is not required in majority of shots. Having areas out of focus adds to the depth in the image and helps lead eye to the main subject. Also, our own eyes don't have front to back sharpness when looking at a scene when we are out in the landscape, so I'm unsure as to why some photographers obsess over it and use focus stack etc. 🤷‍♀

Quite an interesting ramble. I really enjoy how you are walking us through your thought process. The horizontal tree trunk was my favourite. Seems to me you could revisit the first scene with the Intrepid and use some lens tilt to accomplish full front to back sharpness. My rule of thumb is place the focus at the first third of the distance. Seems to work, mostly.

Thank you so much for all your wonderful videos I not only learn a lot with every video but I find them very enjoyable and inspiring.

Great video, I picked up a Bronica SQ-A last weekend with three PS lenses (50, 80 and 150), can't wait to get out in the field with them. Your videos are one of the main reasons why I bought this system.

Great shots. F16 and F22 are my default apertures for landscape on 35 mm and medium format, respectively.

Another super thought provoking video. I always wondered why manufacturers put f/22 markings on lenses if they were totally unacceptable. Seems like they have a use and your concept seems to show how. Many thanks!

Very interesting results and discussion. Empirical testing in the 3-d world always beats charts. Each lens is indeed different, and I appreciate the emphasis on using them enough to know what they are capable of, and what are their limitations. I need to spend a lot more time leaning my equipment. Cheers!

The only time I worried about diffraction was on my Royal Australian Airforce photographic course. There was no way I was going to use f22 and risk a retest 😂

Thanks Steve. I love your practical approach and your eye for an interesting composition. The production quality of your YT videos is always a treat - as is your dry sense of humour.

I'm so pleased to see this video! I mentioned diffraction and voila, here it is! It's OK to have some, in pursuit of more sharpness (apparent). Same as the idea of wide angles having more depth of field. It seems so! One shooting in an artist's studio, had perfect accuracy to focus accurately. I did a wide,35mm, normal 50mm, then the 90mm. When I looked at prints, using magnifier, the real depth of field was same on all. The wide saw more, the 50mm was good and the 90mm seemed less depth of field. The magnifier showed same on all. 6x6 is big these days! Easier to work with!

Every lens at every aperture setting -- even wide open -- has diffraction. As you said, the question is whether the diffraction is worse than the alternative. I generally avoid going smaller than f/11 with 50 mm lenses on 35 mm film, but with a 90 mm on my RB67 (6x7 cm) f/16 and even f/22 don't cause me stress. First, the lens is almost twice the focal length, so f/22 is barely smaller actual aperture diameter than the f/11 on that 50 mm, but second, the 6x7 frame is more than twice the height and about twice the width of the 35 mm frame -- meaning I only have to magnify it half as much for a given print size, so any slight "fuzziness" from diffraction is only half as damaging to the final print as it would be on 35 mm. In other words, f/22 in medium format is still better than f/11 on 35 mm. And go on up to that 8x10 I've seen you haul around and f/45 is no big deal; if you've got a lens that offers it, you might even use f/64 if needed to get the depth of field and let you blur that moving water a little...

Steve, excellent as always. But, take it from a Canadian, never underestimate a gang of savage squirrels.

nice to see in that last shot, you did use the mirror lock up feature, as, even such a small format as 6 x 4.5 does have a big mirror.

*Good video and nice pictures:* According to Fourier optics theory, the diameter of a diffraction spot from a point light source with a wavelength of about 0.5 µm, is about 27-29 µm at the focal plane of the camera when using f/22. Thus, the scan pitch needs to be about 14-15 µm, or about 1800 dpi. On a 6x6 cm frame, this corresponds to nearly 17 megapixels of real image data. Note also, that every point of the image is sampled in this analysis, unlike with a digital camera with a Bayer filter, which employs interpolation (demosaicing) algorithms to generate the image data.

Great stuff as always. I love stopping down for long exposures in the dim woods. The only thing I ever run into is the sharpness is often negated by wind+foliage movement. Also, love that you're using m43; that's how I started (and still use) photography and also use it for digitizing film! Question about your SQ: Is that a Bronica brand square lens hood with a built in square filter holder? None of my Bronica hoods (ETRSI/SQA) have that filter functionality!

Excellent video as always!!! Thanks Steve!!!

Thanks for sharing this enjoyable and informative vlog Steve. I like your humour.

I think the stigma around f/22 is from smaller formats like full frame and aps-c. The larger the film plane, the higher the diffraction threshold. I shoot f/22 on 645 without worrying about diffraction.

People get way too fixated on diffraction. It's a real effect but not nearly as severe as you would think from the hype. When I started in photography you hardly heard of it, it was only when digital cameras with super high resolutions started to make it more obvious that we heard about it in every review. I used to use f32 occasionally on my old Mamiya C33 and it was usable for prints up to 16x20 with no issues (certainly I've never had any comments or feedback on their sharpness!). But more realistically, if you stick to "1 stop above the widest and one below the smallest" it'll usually be fine. Even on my digital Olympus MFT system I occasionally use f22 when the conditions prevent focus stacking. Better a very slightly soft shot than an out-of-focus one!

Must admit to not being worried about diffraction Steve. I used it once to get the effect I wanted and have never thought twice since. I wanted a shot of Kylemore Abbey in Co Galway with a good lot of mist coming off the Lough. Unfortunately the mist was a bit thin but clearly visible. So closed down to f 64, which gave a lovely softness and the feeling of the mist being thicker. Another photographer came over and asking about the LF camera. When he saw I was using f 64 my shot was 'not worth a cr@p because of diffraction' Great debating Vlog Steve. Cheers Diz

Beautiful shots . With my Fuji x system and the 35mmF2 and 50 mm F2 lenses I rarely go beyond F8. That is the advantage of apsc format. :))

PHOTO QUOTE OF THE DAY "Images can describe, abstract, interpret, but they are not absolute." - - Carolyn Drake

The aperture of the 150 mm lens at f/22 is three times the aperture of the 50mm lens at f/22. That's why it has more diffraction. Smaller aperture, more diffraction.

Lovely video !

one other observation, diffraction is not the only issue with f 22 , things like the increased shutter timing (1,2,3,4,8 seconds +), and the necessary tripod steadyness to get no motion blur, infering film choice (asa), as resiprocity failure would come into this with such long exposures, esp. for some stocks of film, also mirror slap, with such long exposures, so m_up use is also essential here to. lens choice also is affected by this apature, as less light gets in, the longer a lens gets, due to size, and amount of glass to refract through; so shorter lenses facillitate more light, so you can do shots in darker areas, as there is less 'systemic' light loss.

This photography game is more dangerous than I thought. Sinking bogs. Squirrel attacks. I might just watch the telly. 😉

f/22 on medium format has the same diffraction on the final print as f/11 on a full-frame 35mm camera, since it needs to be enlarged only half as much to reach the same print size. Nobody complains that their 35mm f/11 image was wrecked by diffraction, so you shouldn't worry about f/22 on medium format either.

I would say that maybe back in the early days of digital, yeah you tended to avoid f/22, but with in-camera corrections now, I wouldn't have a problem shooting at f/22 if I had to. Now the key being "if I had to". Lenses and technology has come a long way since the first days of digital cameras and lenses. Yes there might still be some diffraction in even some of the best lenses of modern day, but usually this is only seen when pixel peeping too, and most people likely won't notice at viewing distance. I'm a sucker for sharpness though with my landscapes, and when I need front-to-back sharpness I'll do the focus stacking first to ensure the best image quality but am not opposed to f/16 or f/22 if I'm on the go. I also think that we are often times show diffraction and shooting at f/22 on a test chart in a controlled environment, and while this will tell the "true" story about diffraction and small apertures, I think it somewhat can over-exaggerate diffraction, as in you may see it on a test chart in a controlled environment, but may not notice it in practice in the field. Test charts are good for checking to make sure lenses don't have any obvious issues (like focus or decentering issues or otherwise checking for overall sharpness at various scenarios -- FLs and apertures, or comparing two lenses) but they aren't always fair comparisons to what you can expect in the field. I think in the field, some of the diffraction is sort of lost in the various textures and color, among other things, unless you're pixel peeping, so you won't notice it as much as you would on a test chart.

Great video, as always. Thanks a lot.

I worry about it often and generally take the lazy man’s way out and bracket. Since I do a lot of macro work, diffraction is always on my mind. I prefer 35mm for macro as it’s really hard working with larger formats as the working distance gets absurdly low, 1:1 lenses are hard to find, and the longer focal lengths make extension cumbersome with medium format. Diffraction definitely becomes much more of an issue at f/22 with 35mm lenses. I’ll shoot f/22 medium format but really try to avoid it with 35mm - I even try to avoid f/16 when possible and prefer f/11 for landscapes with 35mm. On my Pentax 6x7, f/22 doesn’t usually cause enough diffraction for me to be concerned about it and images are usually sharp. As with anything, context is always the key. As you demonstrate, f/22 works quite well in some situations with your 6x6.

I think diffraction will be a little bit more noticeable in the 35mm but as you've alluded too much is relative. Happily my latest squirrel related damage has mostly healed just in time for my day off.

The forest always delievers. Great compositions, Steve. As for diffraction, I am not usually too worried about it if I were using ' normal ' B&W film. With something like the CMS20II, Rollei 80s, Adox/Efke 25 or even PanF, I will be a bit more careful. F6.3 for MFT, F9 for APSC, F11 for FX/35mm, F16 for my Hasselblad or 6X7, and F32 on the 4X5 is my usual working apertures for standard lenses. But, if the composition warants it, I am more than happy to tolerate a bit of the ' Airy Disc ' for extra D.O.F. TBH, with most normal emulsions the resolving power is the limiting factor.

Thank you an interesting video making a lot of sense. Like you I get to know my lenses and know whay thye will do.

I had a Bronica EC with a 50mm Nikkor f4. Ideal for front to back sharpness.

I am not a tripod person so i set my cameras (35mm and 120) at most to f8 or f11 and shoot handheld. So in that sense I don't have to think too much about diffraction.

Thanks for the reminder that it is okay to step down! I fear diffraction so rarely go below f/11 haha though tbh the main reason is because I am always too lazy to use a tripod.... I have heard that diffraction kicks in much sooner for smaller formats (and also for closer distances) so I guess that's worth keeping in mind. Folk seem to use their large format cameras at like f/1 kajillion without a care in the world.

I sometimes print 8 x 8" or even 5 x 5" from ancient, simple lens medium format cameras and the results look fine. Likewise printing from tiny 2/3 sensor digital format cameras. In film days exhibition prints from 35mm negatives rarely exceeded 16" and were often less. 1/250, f8 prints from a 28mm lens were sharp enough to do the job, whereas now near and far subjects would probably be out of focus and may exhibit camera shake when enlarged from a full frame digital sensor.

I'm out this PM with my medium format camera and B&W film. Thanks, Steve. I would never have seen those images. They almost look infrared.

Yes I do worry about diffraction. I mostly stick to f16 on medium format. 645/6x7. I do however move into f22 confidently on my 6x9 rangefinder. It's true though that I do focus stack my film images, though not as rigorously as my digital ones. I am envious of your three compositions per roll :V

On FF, f/22 can be a lot. On MF, it's going to be a lot less pronounced. Go to something like MFT, and you might start knowing it as low as f/8.

My guide for myself is that I think twice at using an aperture that is less than 4mm in diameter. Only a problem I have is with APS-C and M43. It will be interesting to here how you get on with 35mm. P.S. I also use my SQ when out for fun.

4:30 The swirling shape of the surrounding foliage almost gives that image a “Petzval” feel. F128 and be there 😂. Sharpness is overrated, soft focus in the forest is what does it for me.

Much like a brief yeti sighting, I could swear I had a Gary Gough sighting in this video at the brief beach scene, then I realized not all photographers on the beach are Gary Gough, even if they use a 10-stop filter, like not all yeti sightings are yetis. But some sightings are space aliens, or not.

I never worry about diffraction if it means getting the shot or not. I'd much rather have a slightly soft image vs no image at all.

It may be misplaced to throw the focus on the gear you are using, but based on these examples it seems you might have better flexibility using an SL66, with both Scheimpflug compensation and a more useful depth of field scale, all the while keeping the same size and weight of your overall package.

As you say, sharp enough is often good enough, depending on the subject

My Bronica lenses aren't Zeiss sharp so a bit of diffraction isn't a concern of mine. I'll shoot at f/3.5 or f/32 if the shot warrants it.

Brilliant video, as always Steve. What hood do you use with your Bronica lenses? I notice it has a filter holder built into the design. Thanks.

Lovely shots. For the fallen tree scenario, what are your thoughts on using something like a tilt-shift lens to keep the receding tree sharp?

All the great medium format photographers end up with one foot in the dirt. We`re aaaall the same -_*. Love forest swamp. F22 on bronica is like f16 on 35mm, so i think real ugly diffraction starts somewhere one or two stops beyond. People, who make lens know it, thats why you`ll find such f-stops on very "special" lens.

The proof of the pudding is in the eating. Looks pretty delicious to me.

one question Steve, can you do the same, with a multi_exposure image, and focus stack, adding both forground and background shots together ( each at shallower dof's, and adding to a single image). Or another alternative, is take the foreground and background as two separate shots, combining both negs onto the same paper print in the darkroom?

If I have to close down I will I don't care. I do it sometimes with ring photos at weddings.

Hi Steve, another great video. Do you use a macro lens, when you create digital files? Have done a video on your digital file process, I have a Panasonic GX8 would that be suitable?Keep up the good work!

Steve, I love your work and your movies. What's your take on digital camera scanning?

Great video as always. Just ditched my Pentax 645 for the Bronica ETR Si and a new in the box never used SQ-A with 80mm lens. Wanted the ablity to switch films while shooting. What lovely cameras. A question. That looks like a Bronica OEM lens hood on your camera. What is holding the filters on the hood? Is that a Bronica product?

Hello Steve Could a polarization filter reduce the diffraction phenomenon?

IMO if you are shooting consumer film, don't worry about it...

Have scanned your negatives?

Do you develop your XP2 as C41 or with a B&W developer? Also, I take it that you like to use XP2 in this type of situation?

yes, at 5:54, Funny, we all know you, an old guy spilt his chocolate milk!!!! , or was it chocolate brownie?

'clouds aren't sharp' ... that gets a like 😂

“f/ 64 and be there” ;-)

Do I worry about diffraction? No. Use f22 when I need to, some times you get great surprises.

Nope!

No I couldn't care less. I'm more interesting in striving to make interesting photographs.

Putting the issue to rest concerning full frame will be nice. Thanks for the political bog slog!