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SK 35mm and 28mm with Credo 40 or 60?

gebseng

Member
Thought I'd share a very recent image with the 28XL & Credo 60. Last Thursday I did a series of 8 images to the company that built this bridge and this particular one I maxed out a 8mm rise, but the top is still tacksharp without smear.
If you don't torture the 28XL, then it is absolutely FAB also with 60mp big gun.

great! tacksharp, that's what I want to hear!

geb
 

Guy Mancuso

Administrator, Instructor
Thanks Guy! Yeah, I'm aware I'll be losing some wide angle FOV with the 44x33mm sensor. However, compared to my current 48x36 sensor that's only -10%. Right now, I substitute a 23 or 24mm by stitching with the SK35, which works great! And in a really desperate back-to-the-wall (literally!) situation when shooting architecture, I could even do some limited stitching with the credo 40 and the SK24.

Budget vs. focal length: very good point of course. When I started my reasoning about Credo 40 vs. 60, my first idea was to ditch the SK35 and either go for a 32HR with the credo 40 or a 40HR with the credo 60 (which both would be exact replacements considering the change in sensor size). But these Rodenstocks seem awfully expensive compared to the SK-s. Also, colleague photographers told me about more flare problems with the Rodenstocks compared to the SK-s. Another point is that I once had the Roddie 35HR as a loaner, and had some issues with barrel distortion near the outer end of the image circle, which is of course correctable if you jot down your shift/rise settings, but is a real no-go for high-volume commercial work. That's what made me think about keeping the SK35 in first place, and I'm really happy that seems to work out now!

geb
The Roadie 28 does have a little distortion as well. I did a review of the SK 28 and Roadie 28 on the 160. Might want to read that just for some info. I bought the SK but than returned for the roadie. The SK I was seeing some faint magenta cast after my LCC but this was awhile ago and C1 has gotten better at LCC. Still might be worth a read. Just for data finding
 

dougpeterson

Workshop Member
Hi everyone,The (very helpful!) "Tech Camera Overview" on digitaltransitions.com (https://www.digitaltransitions.com/page/tech-camera-overview) list the SK 35/5.6 lens as "compatible" with <40MP backs and as "limited compatible" with 60MP backs.
That's our chart, so thanks for the kind words.

I hope I can elaborate.

In the effort to keep the "overview" simple enough to be useful to someone at the start of their search for a good tech camera kit we did simplify/omit some information.

As you noted IQ140/IQ160/Credo40/Credo60 are all 6 micron backs and as such, if you put any of those sensors in a particular physical position relative to the lens they would react the same. Or put differently a Credo 40 has a lot more in common with a Credo 60 than a DM33 (33mp) or P45+ (39mp), as regards it's reaction to wide angle tech camera lenses.

But reading the chart as-is was deemed acceptable in so far as the IQ140 / Credo 40 sensor is smaller than the IQ160/IQ260/Credo60 and therefore the same amount of movement (e.g. 10mm shift) will result in less intra-frame color/fall-off issues.

I hope this clears it up, or, at the least, does not make it even more confusing.

---

As a side note to all: would it be better for us to switch our column headers to read "5.2 µm, 6.0 µm, >6.8µm" instead of "<40mp / 60mp / 80mp"? Our thought in using the resolutions was that someone just starting their search for tech camera kits would be intimidated/confused by the use of micron size to signify specific backs. Sometimes by trying to be too complete/accurate you can end up obfuscating the most important message. In this case the core message was to make sure clients were aware of, and consider in their search, that some lenses have limitations or are entirely incompatible with specific backs, especially the 80mp ones.
 

daf

Member
Doug: I think the best way for this Information would be to indicate the image circle usable/pixel size.
 

gebseng

Member
That's our chart, so thanks for the kind words.

I hope I can elaborate.

In the effort to keep the "overview" simple enough to be useful to someone at the start of their search for a good tech camera kit we did simplify/omit some information.

As you noted IQ140/IQ160/Credo40/Credo60 are all 6 micron backs and as such, if you put any of those sensors in a particular physical position relative to the lens they would react the same. Or put differently a Credo 40 has a lot more in common with a Credo 60 than a DM33 (33mp) or P45+ (39mp), as regards it's reaction to wide angle tech camera lenses.

But reading the chart as-is was deemed acceptable in so far as the IQ140 / Credo 40 sensor is smaller than the IQ160/IQ260/Credo60 and therefore the same amount of movement (e.g. 10mm shift) will result in less intra-frame color/fall-off issues.

I hope this clears it up, or, at the least, does not make it even more confusing.

---

As a side note to all: would it be better for us to switch our column headers to read "5.2 µm, 6.0 µm, >6.8µm" instead of "<40mp / 60mp / 80mp"? Our thought in using the resolutions was that someone just starting their search for tech camera kits would be intimidated/confused by the use of micron size to signify specific backs. Sometimes by trying to be too complete/accurate you can end up obfuscating the most important message. In this case the core message was to make sure clients were aware of, and consider in their search, that some lenses have limitations or are entirely incompatible with specific backs, especially the 80mp ones.
Thanks a lot, Doug! This makes the chart even more useful to me. As I understand it, the chart is geared more towards the "modern" IQ and Credo backs, since some of the older (Kodak sensors? microlenses?) designs don't perform so well with shifted wide angle lenses?
 

dougpeterson

Workshop Member
Thanks a lot, Doug! This makes the chart even more useful to me. As I understand it, the chart is geared more towards the "modern" IQ and Credo backs, since some of the older (Kodak sensors? microlenses?) designs don't perform so well with shifted wide angle lenses?
Really it's the P21+ and P30+ that are the two that are very problematic with shifted wides (with the 30+ being much worse than the 21+). There are also some Hasselblad backs that fit into this category.

I've just added a note in the details below the chart to explain that. Thanks for pointing it out!
 
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