Large Format Digital Photography

maxotics wrote:

The problem with tilt/shift on all DSLRs in my experience is the flare you get as you move the image. If you tilt up, you're essentially projecting most of the image to the side of whatever is between the lens and sensor. If you have a shiny tube connecting to the camera, even if black, it can reflect that light onto the sensor. For example, I used a Canon TS on my Sony A7 and if I changed the movement too much I'd get flare. So I'd say that's the biggest issue you'll come up against.

Flare is always an issue, of course, but I've not found it to be an insurmountable one.  I also flag my lenses very carefully, as one way to prevent excessive light from bouncing around inside the camera is to limit how much light gets in in the first place!

AudiiDudii wrote:

For example, what focal length range of lenses do you prefer to use? Without a bag bellows, you'll be lucky to be able to use wide-angle lenses of any kind, due to the longish flange-to-focal distance view cameras typically have.

At the moment, I'm more interested in longer focal lengths. Say 75mm up. I have a Canon TS-E 24mm and Laowa 15mm macro/shift that cater for the wider side (for me, for now).

Also, when capturing images with a small-format sensor, the range of movements used will be quite a bit smaller, so greater precision is required than it was back in the film days and geared movements are helpful, too.

That was something I had considered and what lead me towards those cameras, rather than a T/S adapter and medium format lens dangling on the front of the camera.

Better, I think, to buy one of the five used Toyo VX23DS present available on eBay and start with that or buy a Cambo Actus and skip the DIY bits altogether. <shrugs>

The Cambo Actus looks like just the thing but at the moment, my curiosity doesn't extend to that many $$. I just want get a feel for what I can and can't do. The next step may well be the Cambo.

Once upon a time I started piggy backing a film camera on cheap Newtonian telescope on a mount with no drive. Now I have umpteen telescopes, mounts, cameras, etc and an observatory under construction. Start small and then get carried away.

Alas, those cameras aren't an option for me, as they would require me to use at least medium-format lenses and even the shortest one of those is too long for much of the subject matter I photograph. And I'm not sure I need a laptop, either, as a tablet should be able to do the job, but we'll see...

I don't know of any cameras that work with just a tablet (but I don't really follow the tablet side). I think you are limited by drivers to just Windows and Linux. There are a few options that use a Raspberry Pi (or one in a proprietary box) to control the camera and capture the images and then you control that from a tablet. Most of the newer CMOS cameras are lighter than a camera with a similar sensor size. You will have to factor in a power supply for cooling.  Typical draw would average around 1A.

Steve.

SteveInNZ wrote:

I don't know of any cameras that work with just a tablet (but I don't really follow the tablet side). I think you are limited by drivers to just Windows and Linux. There are a few options that use a Raspberry Pi (or one in a proprietary box) to control the camera and capture the images and then you control that from a tablet. Most of the newer CMOS cameras are lighter than a camera with a similar sensor size. You will have to factor in a power supply for cooling. Typical draw would average around 1A.

I'm thinking specifically of the QHY 367C and running it via SharpCap on a Surface Pro 6 tablet ... check it out at QHY 367C.

AudiiDudii wrote:

I'm thinking specifically of the QHY 367C and running it via SharpCap on a Surface Pro 6 tablet ... check it out at QHY 367C.

It's an impressive camera. I was considering it at one stage but there were other options that suited my needs better. I have a few QHY cameras and I use SharpCap a lot. The author is very responsive with both bug fixes and user requests.

How long are the typical exposures with your current approach ?

I do wonder a little if you'd actually gain a great deal over your existing setup. The astro camera is very "no frills" so there's a lot more fluffing around to get an exposure. If you're doing say 5 second exposures, the gain from cooling would be minimal but the time taken to get a result, longer.

Of course, you can always buy a tracking mount and take up astrophotography.

Steve.

ProfHankD wrote:

AudiiDudii wrote:

SteveInNZ wrote:

I don't know of any cameras that work with just a tablet (but I don't really follow the tablet side). I think you are limited by drivers to just Windows and Linux. There are a few options that use a Raspberry Pi (or one in a proprietary box) to control the camera and capture the images and then you control that from a tablet. Most of the newer CMOS cameras are lighter than a camera with a similar sensor size. You will have to factor in a power supply for cooling. Typical draw would average around 1A.

I'm thinking specifically of the QHY 367C and running it via SharpCap on a Surface Pro 6 tablet ... check it out at QHY 367C.

Well that is a very nice little device! Basically, it's a Sony A7R sensor, with cooling, packaged for raw access over USB3. Seems to be about $4.4K, which is really cheap for what it is. Tempting indeed....

And it doesn't use Sony's funky lossy compression scheme, writes truly raw data (so no "star eater" issues!) and also doesn't drop back to writing 12-bit files for exposures longer than 30 seconds. Plus, it has no IR filter, so I can use it for daylight IR photography, too! Not only that, but its form-factor -- no deep, built-in handgrip! -- makes it quite easy to mount it on all three of my FrankenKameras and/or swap it between them in just a few seconds.

It only does 3.2FPS at full resolution, so scanning a large area isn't going to be blazingly fast....

Although I have some concerns about using a rolling shutter, 3.2 FPS is fast enough for my purposes. I'm also concerned about how well it will perform using a B+W hot filter for daylight photography. Both of which are the main reasons I want to try one before buying one, because it won't be the bargain it otherwise appears to be if I can't get it to work well for the type of photography I do.

SteveInNZ wrote:

AudiiDudii wrote:

I'm thinking specifically of the QHY 367C and running it via SharpCap on a Surface Pro 6 tablet ... check it out at QHY 367C.

It's an impressive camera. I was considering it at one stage but there were other options that suited my needs better. I have a few QHY cameras and I use SharpCap a lot. The author is very responsive with both bug fixes and user requests.

How long are the typical exposures with your current approach ?

Because of the image quality limitations imposed by Sony's lossy compression scheme and firmware that causes the A7R's bit depth to automatically drop back to just 12 bits for exposures longer than 30 seconds, I try to keep my exposures under 30 seconds.

But that's not an accurate indication of my needs, as I generally pass on taking photos that require longer exposures due to the inevitable loss of image quality.  Realistically, 240 seconds is probably long enough, although I can probably use 360 seconds a few times each year.

I do wonder a little if you'd actually gain a great deal over your existing setup. The astro camera is very "no frills" so there's a lot more fluffing around to get an exposure.

Yes, I know.  But I already do quite a bit of fluffing about now, both before and after the actual exposures, so I don't believe this will prove to be a problem.  That said, though, it is yet another reason why I really want to try one before buying one!

If you're doing say 5 second exposures, the gain from cooling would be minimal but the time taken to get a result, longer.

Go back and look at the median-blended example I posted.  Those photos were taken at an ambient temperature of around 65 degrees; increase that 40 degrees and it will look as though fireflies are having their annual convention there!  The noise and numbers of hot/stuck pixels increases so dramatically when the ambient temp is over 100 degrees I usually put my camera away and simply stop photographing during July and August.

Of course, you can always buy a tracking mount and take up astrophotography.

That's not too likely!  Because the light pollution around here is pretty bad (although I like it for my urban nighttime photos!) and the urban lights of the Phoenix metropolitan area are still visible 90 miles away from the city, I will need to drive two hours each way to find good seeing and that's just not possible with my schedule.

But even more than that, it simply doesn't interest me.  I took a few elective courses in college, but the bug never bit me. 

Yes, I've worked on designs that could do something along those lines.  I also looked into the QX cameras, cameras for microscopes too, etc.  I have built a robot using a stepper board from Evil Mad Scientists and python scripts to control those, camera, etc.  
I don't have enough interest/use in these systems I've built and most of the photo world isn't even remotely supportive, don't know how to put that.  So am no longer working much on this stuff but have cameras for my own use and anyone who has real large-format love in their heard   If you want to talk on phone, just DM me your number and good time to talk and I'm happy to tell you all I know.

Charles Chien wrote:

Hi maxotics and AudiiDudii,

I had been thinking of such a setup a while back since I purchase one for Mamiya to e-mount (not compatible with A7R) from Fotodiox. I had been thinking of improving something like this - in your case, you take 40 shots to get a 5x7 - what if you are able to place two A7R, one at position #1, and the other at #21, then you only need you gig 20 times cutting the time in half. That's one of the reason that I had been eyeing on something like in the form of Sony QX1, which is very small compared to a regular camera. Unfortunately QX1 does not have manual mode so it isn't suitable for this application. But imaging Sony has a full-frame camera in Sony QX1 form, it would work perfectly, and you might be able to put 4 of those with cameras at positions #1, #3, #21, #23 at a time - taking only 12 shots for get a 5x7. In any case, hope to see more of this from you two. And, please also feel free to PM me with this.

This isn't the answer you're probably hoping to hear, but based on my experience with the trio of Sony RX1 cameras I have, I'm not optimistic about this approach working very well.

Because I am skeptical that you can find three camera bodies and lenses that perform similarly enough that their files can be combined seamlessly.

For instance, I can readily see differences between the files captured by my three RX1s.  Not only in terms of sharpness and resolution, but also with color and exposure, which varies very slightly, but noticeably between them.

There are also potentially a few other issues that come to mind, but this is the foremost concern I have with your propose project.

But who knows?  For your purposes, perhaps the files don't need to be identical in every respect and this approach will work very well for you.  So perhaps give it a shot and see how well you like the results?