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maximum exposure with current digital backs ?

archivue

Active member
i've just read that : " The increased long exposure capability of the Credo 80 to 2 or more minutes based on temperatures also seemed like a great bonus over the 32 seconds I had with the Aptus II."
source : Upgrading to the leaf credo 80 by Robb Williamson / Luminous Lanscape

i know the IQ 260 is the best in this regards, but what are the limitations of the others ? 2mins seems enough for architecture…

Credo 60 ?
IQ 160 ?

thanks
 

dougpeterson

Workshop Member
For Phase/Leaf:
Most 40/60mp models: 1 min @ ISO50 (includes Credo 40, Credo 60, P40+, P65+, IQ140, IQ160), with the exception of IQ260 which has a long exposure model capable of 1 hour exposures @ ISO140
80mp models: 2 min @ ISO35 (Credo 80, IQ180, IQ280)

These specs are a good rule of thumb, but will vary based on ambient temperature, and what your quality requirements are. In really cold environments you can get quite a bit longer than the spec; in really hot environments quite a bit shorter. In general these backs all have a fairly strong "cliff" such that 20-30 seconds shorter than this spec the quality is quite good, and 20-30 seconds longer than this spec is quite bad. But none of them have a "hard limit" programmed into the firmware where the back stops working - it just gets progressively noisier.

Contact your dealer for relevant sample raw files, and/or an evaluation rental, so you can make your own judgement on what's good, acceptable, and barely usable for each back.
 

archivue

Active member
Thanks !

Is there a major improvement at around 28s exposure between an Aptus II 7 and a Credo 60 ?

with the improvement of C1 (v6… v7… v8) … semi long exposures are much better than they used to be, even with an altus 22 !

Anyway i can't afford an IQ260, and i prefer my leaf Aptus II 7 over a P45+ in therm of colors ! So, i will probably test an IQ160 or Credo 60 at 50s sometimes...
 

archivue

Active member
i've received the credo for Testing !

few problems :
- My RM3D was calibrated for my DM33... it looks like, the credo is about -1.4 ... so i can't reach infinity...
- My dealer send me just one battery and no charger, you can charge the battery via FW but it takes ages ( i've borrowed a friend's charger)
- The in back live view is really crap... crappier the live view in computer using Aptus 22 and Leaf capture
- My Leaf FW800 cable doesn't fit, but my unibrain is ok


Good points
- the screen is excellent
- navigation is quite good... except few things : you can't have access to the leveling tool if there's no image in the card (maybe i'm wrong?) and my fingers are too bigs sometimes ;-)
- when i compare it to my Aptus II 7 (DM33) for exposure around 10 to 30s... everything being the same, the credo seems much more sensible.
- sound allert much better
- feels solid and really well built... fits nicely the RM3S

now i have to open the files... that was just a quick test, it was windy, and i wasn't shure of my calibration... so i won't post crops for now... not a serious test !
 
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Paul2660

Well-known member
While you have the Credo 60, see if you can borrow a laptop with USB 3 and experiment with tethering. The USB3 connection really makes a big difference. The Surface Pro 2 or 3 really are a great compliment to the USB3 connection.

Your findings with Live View are to be expected. CCD's can't refresh fast enough and bloom terribly. You also heat up the CCD pretty quickly in live view thus creating more noise. Battery life will suffer also.

Paul
 

archivue

Active member
While you have the Credo 60, see if you can borrow a laptop with USB 3 and experiment with tethering.
Paul
a lap top in the field it's not an option for me... i'm in a city where you have to watch for you stuff while shooting...
+ 1 rm3d + 5 lenses + tripod + batteries + disto + lcc +... is enough for my back...
 

archivue

Active member
Rodenstock 28HR... sensor size...

while i will probably have troubles to use movements with my current lens arsenal ( 28HR, 35XL, 45ASD, 55ASD, 72L ) with a large sensor as the Credo 60... i will lost quite a lot of angle of view with the Credo 40 and 50 compare to my current DM33.
 

archivue

Active member
I hope that tonight i will be able to shoot more images... if there's no wind...

But for now, my conclusion are :

Credo 60 is really a good back :
Great colors
Great interface (except the strange navigation for the leveling tool)
Feels really well built
Good screen
Being able to use it as an aptus or as a P+ with technical camera is a real +
Having a leveling tool even if not perfect is really good
The look is great... it looks it was made for a RM3D ;-)

Credo 60 VS DM33 (aptus II 7)
- Larger files, but in C1 with my "old" Mac Pro i didn't find a lot of change
- larger angle of view ... great of course, but less movements available
- the Credo 60 looks more sensible !?

And finally, if i was shopping for a back for general purpose photography, credo 60 will be in my really short list !
Actually, my DM33 serves me quite well... i wanted to test the Credo 60 for semi long exposure... in that domain, it's a little bit better than my DM33, but not enough to justify to swap ;-(
The best tool for MY STYLE of shooting, is probably the iQ260 but i just can't afford it now !
So, i will continu with my aptus, (maybe i will ad a second hand P45+ to my collection specifically for long exposure)... and i hope that later i will buy a IQ260 or the credo equivalent... or even a Credo with a CMOS sensor that can handle lens movements and long exposure !
 

weinlamm

Member
Good morning,

why do you think that the Phase IQ260 is better than the Credo 60 for you? There are some points different - but from the sensor-side they should be the same.

And Live-View:
Why crappy to you? Because of the frames (Phase should be the same; only the new CMOS-sensor is better: IQ150, 250 or Credo 50) or have you a problem with "to much light"? The second thing is the reason, why I allways have a grey-filter in my bag.
 

archivue

Active member
Good morning,

why do you think that the Phase IQ260 is better than the Credo 60 for you? There are some points different - but from the sensor-side they should be the same.
The iQ 260 is The back for long exposure... as P45+ was before !

the liveview eats the battery in 10min of shooting !

the quality is far from good
i have tried to focus with it for interiors... the light level was perfect for it. the focus was off !
 

weinlamm

Member
The iQ 260 is The back for long exposure... as P45+ was before !
Ok. That's a reason I could understand. It's an totally other kind of photography if you need to shoot long exposure.
But I don't understand why you compare then with your DM33... With this you have only 32sec - and then 'shut down' without an picture. With an Credo you should keep a picture on your card. For me (I had a DM22 earlier) a big plus.

the liveview eats the battery in 10min of shooting !

the quality is far from good
i have tried to focus with it for interiors... the light level was perfect for it. the focus was off !
I can't say too much about this theme: I only use Liveview with my Cambo sometimes to control how wide I'm really shifted (to control via the Viewfinder is not as easy...). And sometimes if I shoot Macro.
So I'm not working very long with this. For my use it's 'good enough'.

But you are right. With a DSLR or the new Credo 50/IQ150/IQ250 should have a much better Live View. I had seen this a Photokina - the Live View of the new Credo 50 is much better. But: then you have an other Sensor-size... :shocked:
 

archivue

Active member
But you are right. With a DSLR or the new Credo 50/IQ150/IQ250 should have a much better Live View. I had seen this a Photokina - the Live View of the new Credo 50 is much better. But: then you have an other Sensor-size... :shocked:
the credo 50 isn ´t an option for technical camera, you can ´t tilt or shift the lens... similar as a p30+
 

Paul2660

Well-known member
the credo 50 isn ´t an option for technical camera, you can ´t tilt or shift the lens... similar as a p30+
Actually, the review that Guy did shows that the Credeo 50 and IQ250/150 can work fine with technical cameras and movements. Of the lenses you listed as owning, I believe only 1, the 35XL will have problems with movements.

Voidshatter's post:
http://www.getdpi.com/forum/medium-format-systems-digital-backs/52000-lcc-23hr-35hr-40hr-iq250.html

Clearly shows how well the 23HR does. It gets better movements than with the full frame CCD backs. Once again he did a lot of work, and testing with various lenses, and thanks to him and his dealer for the information.

You might have to sell the 35XL, and get the 35HR, or move to the 40 HR-W. The 40 HR-W did very well with the Credo 50, up to 15mm of movement. More than enough for a lot of work.

The IQ260, IS NOT anywhere as clean as the P45+ in long exposures. It still has a lot of stuck pixels and noise issues. I own one and am not that impressed with anything longer than say 3 to 5 minutes. It may do better in the winter with cooler temps, but most of my testing was in the spring in my area, and it was between 56 and 69 degrees F, which is in the correct range.
The P45+ I owned, easily did 45 to 1 hour shots that were really very clean, and still held a lot of details. I did a lot of night photography and late evening work with the P45+ and it's long exposures IMO are still the best for CCD.

The 250, has everything you need, if you can live with the crop, of 1:3, which with wides will be considerable. It's the cleanest back out there, much better than the P45+ for 30min to 1 hour exposures and the best for the 30 second to 5 minute work. You can get the same abilities with a Credo 50, just no wifi, which is currently not too much to miss. Live View on the CMOS is excellent, and becomes a workable tool, and your battery life, no longer takes a huge hit, and it seems the sensor doesn't get as hot/noisy when using it.

I would not rule out the 50 backs, and the same dealer that allowed the eval for you on the 60, might be able to get a 50 for you. It would be most interesting to see what you think after you test it.

Personally for me, as a IQ260 owner, if I could get around the 1:3 crop issue, I would have long ago traded in my 260. Guy's testing showed that movements for the lenses I own, except the 354XL are still very possible. There is still some question on the 60XL, as it had issues with the first testing DT did, and as far as I know DT never followed up with it. If they did, I never saw the results. For my work 15mm of movement shift is about the max I can get with the 40 HR-W on a 260 anyway, as the built in image circle marker starts to hard vignette by 16mm. The 250 would go further, up to 18mm as you won't hit this marker as soon due to the crop but the sensor crosstalk issues start to show up pretty harsh.

Right now, I am still in the process of considering a switch to the IQ250, working with a dealer as Phase offers no good trade in solution for the 260 to 250 route. I know that the next big thing is coming sometime next year, and it seems it will be a Sony chip, full frame or 1:1 like the P45+, however the issues with tech lenses still may be an issue and with the larger chip, unless a huge design change is made, the issues will be exacerbated.

I would not rule out the 50MP chip solution until you try it in your working environment.

Paul
 

torger

Active member
Yes I would not rule out the Sony CMOS which can produce good real-world results if you keep within it's limits. Overshifting leads to sudden breakdown due to the offset microlenses which has caused some of the initial tests look worse than it is.

Still it's far from an ideal match with the tech wides and you push a good bit past the designed boundaries. The sensors very low noise and high DR together with Capture One's robust demosaicer and good LCC algorithm make the real-world results quite good even when pushed to quite high amount of crosstalk.

From an engineering standpoint I don't really like this type of system design with ill-matched components, but can't deny that real-world results are still often very good as demonstrated in Guy's Credo 50 review.

There is no single back today that's best on everything, and it's very personal what aspects one can compromise with. After seeing Guy's review and Voidshatters post I think there are many users that will be pleased with it even for tech wide angle work, assuming Rodenstocks are used of course.
 
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