Imaging Source DMK21

[Merlin66]

Seeking opinions/ comments.
Is it worthwhile, for solar imaging, to upgrade from the base DMK21 to the new 618 version??

[marktownley]

Not tried it, however have heard a few people say it's more sensitive in Ha so they get shorter exposure times... You could get shorter exposure times by just removing an ER... (sorry, i'll stop it!)...

[NandoPG]

Merlin,
Just regarding solar imaging, I wouldn´t. The extras you are going to get with this camera is almost none if you compared with your DMK21.

For me what is important in a solar camera is: native sampling capability, what is provided by the pixel size, the size of the sensor, speed in frames per second e low noise.

My point is, in the case of the Sun we have lots of energy in the images to be captured so that noise normally is not a primary issue. Likewise, the solar phenomena are relatively slow and 12 to 15 fps is a frame rate more than reasonable.

Concluding, I think that a great benefit would be achieved by upgrading from a DMK21 to a DMK51AU

Fernando

[oldfrankland]

Seeking opinions/ comments.
Is it worthwhile, for solar imaging, to upgrade from the base DMK21 to the new 618 version??

Spectral response curve shows a very significant increase in sensitivity at 6563A. Higher shutter speed at 60fps is always desireable when shooting close ups of prominences. An activated prominence that syphoning or backstreaming blurs terribly if your exposure time is slower than a couple milliseconds and at less than 60 frames per second.

I took delivery of a '618 last week but have not had a chance to get out with it yet. Hopefully in the next couple days.

[Merlin66]

Hmmm
The 60fps frame rate infers you can use an exposure value < 1/60s. I can't get anywhere near this on proms with my double stack SM60....so maybe the increased Ha sensitivity could help?

[Photonist]

Merlin66

I would recommend a real upgrade to Basler Ace ACA1300-30gm. It is a GigE camera, but I had no problems. In Europe it is available from for example Airylab in France. They have excellent service (also in English) and they even includes the superb capture program called Genika in the camera price. Take a look here:
http://www.airylab.fr/index.php?option= ... &Itemid=71

There is much information on different CCD chips, presentation, faq, tests, amateur images etc. The user guides and software interface is in English. See http://www.airylab.fr/
Use menu Systemes d’imagerie – Cameras Basler
and here http://www.baslerweb.com/products/ace.html

More nformation on the Genika software is here http://genicapture.com/
and here http://www.airylab.fr/AirylabUS/index.p ... /astronomy

I bought it last spring and would not even consider anything else (for Europeans). It is excellent and very versatile and also sensitive to Ha. To use the full capacity of the camera you need a modern laptop to handle the huge data flow.

Viljo

[NandoPG]

Viljo,
You are absolutely right, this camera means a real upgrade !! I didn't know the camera, but I can say I am amazed with the specs, namely:

Pixel Size: 3.75um x 3.75 um
Pixel Matrix: 1296 x 966
Frame Rate: 32 fps at full resolution
Quantum Efficiency (IR): around 54%
Data Interface: The very convenient Ethernet.

It was not clear (I don't read French at all) if the internal ADC is 8 or 10 bits.

I just bought a Flea3 from Point Gray Research for my planetary images, but I fell in love for this camera. Needless to say that it is already in my wish list.

Fernando

[Photonist]

Fernando,

I don’t know about the internal ADC being 8 or 10 bits or not. The specs say the camera works in Pixel Bit Depth 8 or 12 bits and packed 12 bits. Anyhow the data flow using 12 bits is so huge that only a few people have laptops that can take more. However, there is a great Area Of Interest feature that is sometimes helpful if you want greater speed or smaller data flow.

A moderate modern laptop will do with the camera, but the critical point is the hard disk. A SSD hard drive is a must for using full speed and resolution. Luckily my laptop had a second empty hard disk bay so I installed a 120GB SSD disk which should be enough for a one day imaging session. It works great but must be copied somewhere and emptied after one or two sessions. If the disk gets full during imaging, I don’t get any warning and have empty files. I learned it the hard way after two failures.

The camera is super small, about thumb size. It produces SER files which work great in both AviStack and Registack.

The camera needs the free Pylon driver software from Basler for the GigE but no problem with it.

Viljo

[solarchat]

I currently own and use the DMK21 old style and new style along with the PGR Flea and Chameleon amontg others.

The newer DMK21 is a gigantic leap above the older chip style. It is much more sensitive for prominences and very close in AR shots, which is the only reason I use it. The 640X480 resolution of the camera leaves a lot to be desired when doing full disk shots but the camera is perfect for use with a 2.5X barlow or higher. The 60fps allows you to basically freeze a prominence in time to get a highly detailed, almost motion free image.
Still it is hard to go from 1600X1200 on ly other cameras down to 640X480 . The pic I had published in on the Nat Geo website this year was taken with the new DMK21...(by a 9 year old , sorry pro imagers..it aint that hard):)

[Merlin66]

Viljo,
Basler Ace ACA1300-30gm Looks good, but what about the pricing??
(Nothing obvious on the AiryLab site?)
EDIT: Found this link:
https://www.rhpstore.com/basler-ace-aca ... p-412.html

Looks like $767 in the US, probably more in Euro???

[NandoPG]

Viljo,
There is a huge difference when the conversion of signal out of the sensor is performed using a 10 or 12 bits ADC and when ADC is a 8 bits and after the conversion they upconverte the file to a higher bit space using some piece of software.

But even if a 8 bits ADC for the Basler camera is something amazing.

Space for storage nowadays it is so cheap that I think it is not an excuse for not to use a high end camera like this. I have a HD of 750Gb on my i7 and a Firewire B server (800MB exchange ratio) where I can connect up to 2 x 1TB external HD. Currently I have just 1 connected to the server. All of this scheme cost me less than US800,00 and problem solved once and for all.

Fernando

[Photonist]

Ken,

The AiryLab site has the pricing here on the Tarifs page
http://www.airylab.fr/index.php?option= ... &Itemid=66

The camera costs 730 EUR plus the power adapter of choice around 55 EUR. I chose the POE injector option to have only one cord to the camera. Note that the excellent Genika software is included when buying from AiryLab (it is their own product). Bought separately Genika cost 50 EUR. There are a few free programs but I have not had success with them (last time I tried).

Viljo

[Photonist]

Fernando,

Hard disk size is not the problem, I meant the disk speed. That’s why I mentioned the SSD drives. On the AiryLab pages there are much information on disk speed. I did not believe it at first and thought that a modern fast 7500rpm hard disk would be enough, but no. The frame rate was much slower than specified and sluggish. I tried many tricks and optimization of the laptop but all in vain. If you want full frame rate and resolution, a SSD disk is needed or something as fast. The GigE interface is fast.

Viljo

[Photonist]

Ken,

I have not followed the price of other options lately as I do not see any need for the near future. Anyhow, I would sell almost anything to get the Basler. But note that some people need to upgrade their laptop, at least to a really fast disk drive. To get started an external cheap USB3 disk might work if you have the connector on the laptop. However you get only decent speed, not full speed.

One important detail to consider and check is the GigE interface on the laptop. Some brands can have problems. I have used the Basler on three different laptops without problems. There is detailed guidance on AiryLab and Basler pages.

Viljo

[oldfrankland]

I currently own and use the DMK21 old style and new style along with the PGR Flea and Chameleon amontg others.

The newer DMK21 is a gigantic leap above the older chip style. It is much more sensitive for prominences and very close in AR shots, which is the only reason I use it. The 640X480 resolution of the camera leaves a lot to be desired when doing full disk shots but the camera is perfect for use with a 2.5X barlow or higher. The 60fps allows you to basically freeze a prominence in time to get a highly detailed, almost motion free image.
Still it is hard to go from 1600X1200 on ly other cameras down to 640X480 . The pic I had published in on the Nat Geo website this year was taken with the new DMK21...(by a 9 year old , sorry pro imagers..it aint that hard):)

Yup. No single piece of equipment is perfect for everything. 640x480 compared to 1600x1200 is definitely apples and oranges.

Killer about the Nat'Geo shot by one of your 9 year old students!

[oldfrankland]

Interesting. According to the Point Grey web site, spectral response curves for the ICX445 and ICX618 CCDs are essentially identical.

http://www.ptgrey.com/support/downloads ... ICX445.pdf

Of course, it is a given that the characteristics of the CCD is only part of overall camera performance.

[oldfrankland]

After spending a couple hours with the DMK21618, I can only echo what Stephen said about the camera being a significant step up from the original DMK21. Far more sensitive, especially noiticable when viewing and imaging prominences. If shooting at high magnification with 640x480 is your thing, this camera is killer!

Seeing is typical winter stuff here in the SF bay area, but may have a couple shots with the 618 to post. The flare loops I shot on Friday were the first images with the camera. Thus far, looks like money well spent.

[astroflyer]

Viljo,
Basler Ace ACA1300-30gm Looks good, but what about the pricing??
(Nothing obvious on the AiryLab site?)
EDIT: Found this link:
https://www.rhpstore.com/basler-ace-aca ... p-412.html

Looks like $767 in the US, probably more in Euro???

I purchased my Basler Ace ACA1300-30gm from Xagyl.com
Currently CA$645.75 ~ 490.962 EUR
Great service & very quick shipping.

[MapleRidge]

Hi Ken...

I have the 618 chipped DMK21 camera but have only used it for planetary work. It does have a substantial improvement in the near IR when imaging with several IR pass and Methane bandpass filters. The small chip area is in my mind its only real downfall, but to focus in on smaller regions it would work very nicely.

Note, my comparison is against the Lumenera cameras I have used for solar/planetary...the Infinity 2-1M and Lu-075M).

If you want a flexible system, we either need multi cameras or a larger chip that you can use smaller ROI to cature smaller areas when you don't need the full array and avoid slow downloads and filling up storge space with un-wanted data.

Someone mentioned the response curves of several chips...and I have a small issue with the Sony charts...wonder what others think. They do not list the absolute QE for the chips, just realtive respsonse to the maximum. How can we objectively rate one chip at a higher QE if the baseline or relative scale is not standard?

Brian

[Merlin66]

I have the Std DMK21 which has worked well for me for the last few years - yes, I think it would be a good upgrade, but my $$$ are going towards a CaK filter set-up. Anyway I have the DMK41 firewire which is good.
Re the QE curves...we generally make the assumption that the peak will be around 60%.